MX2008008764A - Fermented milk or yoghurt powder with a high density of lactic ferments - Google Patents

Abstract

The present application relates to a fermented milk or yoghurt powder which contains very high contents ofS. thermophilusandL. bulgaricus, and which exhibits exceptional storage capacities. In the powder according to the invention, no substantial loss of liveS. thermophilusandL. bulgaricusis observed after four months of storage at 2O°C. The powder according to the invention has microbiological characteristics such that it itself corresponds to the name yoghurt or fermented milk.

Description

FERMENTED MILK OR YOGURT IN POWDER WITH A HIGH DENSITY OF LACTICAL FERMENTS Field of the Invention The present invention relates to the dairy industry and the food industry. It refers to a fermented milk powder or yogurt comprising at least a quantity of Streptococcus thermophilus and at least a quantity of Lactobacillus bulgaricus and having a high concentration of live or viable lactic ferments. It also relates to means for producing that powder and more particularly to a process for the production of yoghurts or fermented milks with high concentrations of live or viable lactic ferments, to a process for the production of the powder from those yogurts or fermented milks already intermediate and final products made or obtained through the performance of these procedures. It also relates to the applications of the powder according to the invention in the food field, and more particularly in the field of dairy products, cakes and sweets. BACKGROUND OF THE INVENTION In the prior art numerous trials have been conducted for the production of fermented milk or yogurt. The solutions of the prior art have not made a symbiosis between S. thermophilus - L. bulgaricus, exerted in the dairy substrate in such a way that the substrate is transformed into a product in powder form that is suitable for human consumption, and that responds to the name of fermented milk or yogurt, with a population of lactic ferments, and in particular S. thermophilus , at least equal to 5,108 cfu / g, and / or with a population of L. bulgaricus of at least 1,104 cfu / g. Indeed, the prior art applications generally describe the spraying of culture media: these culture media can not lead to a product that responds to the appeal of fermented milk or yogurt. In addition they generally can not be administered to the human being. This is the case, for example, of the solutions described in EP 0 924 993 B1 (Sociedad des Produits Nestlé SA), which discloses a dehydrated food containing lactic acid bacteria, and of patent EP 0 818 529 B1, which discloses a process of spray drying (Sociedad des Produits Nestlé SA). In both cases, the lactic acid bacteria are supplied in the form of a pre-concentrated culture medium. The food product obtained according to the teachings of the prior art is a food that is not a fermented food. The present invention proposes a fermented milk powder or yogurt that responds to the appeal of fermented milk or yogurt, this means a fermented milk powder or yogurt with high content of S. thermophilus and L. bulgaricus alive or viable. The powder according to the invention is the result of a lactic symbiosis, and presents high contents of S. thermophilus and L. bulgaricus, without the need to add live lactic ferments before inoculation by fermentation. The powder according to the invention has particularly high contents in S. thermophilus and L. bulgaricus: in fact they are considerably higher than the legal requirement to receive the appeal of fermented milk or yogurt, and it has remarkable preservation properties. Brief Description of the Invention The present invention relates to: - a process for the production of yoghurt or fermented milk with high concentration in lactic acid bacteria, - a process for the production of fermented milk powder or yogurt, the powder is obtained from of a yogurt or fermented milk with a high concentration of lactic acid bacteria, and having a high concentration of lactic acid bacteria, - an inoculated milk substrate, which can be obtained as an intermediate product during the production of the yogurt or fermented milk process according to the invention and / or during the execution of the Process for the production of powder according to the invention, - a yogurt or fermented milk, which can be obtained as a final product of the Process for the production of yoghurt or fermented milk according to the invention, and / or as a product intermediate during the performance of the powder process according to invention, - to the final product obtained with the process for the production of powder according to the invention, this is a fermented milk powder or yogurt, - to compositions, and more particularly to foods, such as cakes, sweets, containing at least one powder according to the invention. The fermented milk powder or yogurt according to the invention has a high concentration of live or viable lactic ferments, and more particularly S. thermophilus and L. bulgaricus. It is the result of a symbiotic activity between S. thermophilus and L. bulgaricus: it does not correspond to a juxtaposition of inoculations that would be simply added in a more pulverized medium, rather to the preservative pulverization of a milk after the symbiotic lactic fermentation exerted by S thermophilus and L. bulgaricus. The fact that the powder according to the invention has high contents of S. thermophilus and L. bulgaricus, and that it is the result of the exercise of a lactic symbiosis between S. thermophilus and L. bulgaricus, leads to the fact that the powder according to the invention responds to the appeal of fermented milk or yogurt. The fermented milk powder or yogurt according to the invention has a high concentration of live or viable lactic ferments, and more particularly S. thermophilus and L. bulgaricus. According to the applicant's knowledge, the powders of the previous technique do not have a composition and contents of lactic ferments, which confer the appellation of yogurt or fermented milk. In fact, commercial yogurt powders commonly have a very low residual lactic flora, which in the prior art is considered as advantageous from the technological point of view which gives it a great organoleptic stability. Certain commercial powders have very high lactic ferment contents, but using an enrichment procedure after drying (input of exogenous bacteria). They also have high contents of S. thermophilus, but hardly measurable contents of L. bulgaricus. Finally, it is further stated that the yoghurt powders contain high contents of lactic ferments, or even with a stable quality for 6 months at room temperature; but the measurements made by the applicant on these powders, detailed below (see examples 12 and 13 below), show that the actual initial population is lower than advertised, and that these powders do not have sufficient stability during storage, leading to to a significant decrease in lactic flora. The powder according to the invention has remarkable preservation properties, both at 5 ° C and at 20 ° C. For example, at the end of 4 months of storage at 20 ° C, there is no substantial decrease in living or viable populations of S. thermophilus and L. bulgaricus. At 35 ° C, a progressive decrease of the lactic flora is observed, but with a speed generally comparable to the of commercial powders stored at 5 ° C or 20 ° C, preservation conditions considered ideal by the expert. According to the applicant's knowledge, none of the powders of the prior art does not have both: - a content of S. thermophilus and L. bulgaricus thus high, and - good preservation properties, such as the powder according to the invention (cf. examples 12 and 13 ahead). In the present invention, ST (or St) means Streptococcus thermophilus, and LB (or Lb) means Lactobacillus bulgaricus. Brief Description of the Drawings Figure 1 presents the major types of flow curves obtained by the application on a model of fermented milk with a decreasing and increasing tear gradient: upper curve, medium of high viscosity (lactic derivatives of the filamentous type); curve of a medium, medium viscosity medium (lactic derivatives of the textured type), curve below, medium of low viscosity (lactic derivatives of the brittle type). Figure 2 illustrates the determination of the viscosity of a fermented milk model from the descending part of a flow curve obtained by applying an increasing gradient and then decreasing tear (viscosity = slope of the regression line of the descending part of the flow curve, showing in the abscissa the square root of the tear gradient and in the ordinates the square root of the difficulty).

Figure 3 presents a scheme of the soft atomization device adapted for the production of a powder according to the invention. Figure 4 shows two acidification kinetics: - bottom curve: kinetics of acidification obtained by inoculating a milk substrate with an ST strain with a content of 2.7.109 cfu / g and a strain of LB with a content of 1, 4.107 cfu / g (inoculation according to the invention, which leads to a yogurt according to the invention), and - upper curve: kinetics of acidification obtained by inoculation of an identical dairy substrate with the same strains of ST and LB, but at doses lower than those previously known by the invention (inoculation of ST at 1.1O7 cfu / g, and from LB at 5,104 cfu / g). Figure 5 illustrates the initial population differences of ferments (in this figure, "Danone 1", "Danone 2" "Danone 3" and "Danone 4" the powders of the present invention, while «Dr. Süwelack M / A 5.4 Active »,« EPI PY48 »its the prior art powders). Figure 6 illustrates the stability of the ferments in the powders of the invention preserved at 35 ° C for 2 weeks (in figure 6, «DANONE 1», «DANONE 2» «DANONE 3» and «DANONE 4» its the powders of the present invention). Figure 7 shows the evolution of the speed constant (product k x C0) depending on the storage temperature. In figure 7, «DANONE 1», «DANONE 2» and «DANONE 3» the powders of the present invention, while "Suwelack" (= "Dr. S? welack M / A 5.4 Active") and "EPI PY48" its the prior art powders. Figures 8A and 8B show the evolution of the normalized population in lactic ferments during the course of time for the commercial powders, and for the powders according to the invention. The powders of the invention are "DANONE 1", "DANONE 2" and "DANONE 3", while "Suw. M / A 5.4 Active »(=" Dr. S? Welack M / A 5.4 Active ") and" EPI PY48"its the prior art powders. Figure 8A: master curve in linear coordinates (thick solid line = order 2, dashed lines = order 2 plus or minus 20%) Figure 8B: master curve in logarithmic coordinates (solid continuous line = order 2, dotted lines = order 2 more or less20%) Figures 9 and 10 show the cumulative survival values of ST (figure 9) and LB (figure 10), as a percentage of the initial dose after passage through the stomach and small intestine.

Figure 9 (ST): raw or filled powder of the invention (the three upper curves), compared to a reference yogurt (bottom curve) obtained from inoculation doses lower than those pre-known by the invention. Figure 10 (LB): powder of the invention - raw powder - (upper curve), compared to a reference yogurt (bottom curve) obtained from inoculation doses lower than those previously known by the invention.

Figure 11 shows the survival cup ST + LB measured during the course of the preservation at a temperature of 20 ° C of the powders of the invention («Danone 1», «Danone 2» and «Danone 3 »), And of a powder available commercially (« Dr S? Welack »=« Dr. Suwelack M / A 5.4 Active »). Brief Description of the Invention The invention object of the present patent application proposes a technical solution to produce: - a fermented milk or yogurt with high concentration in lactic ferments, under living or viable form, without it being necessary to proceed to the addition of bacteria lactic that does not participate in the lactic fermentation and / or that will be added later to the inoculation, and without it being necessary to concentrate the fermented dough, and - a fermented milk powder or yogurt with high concentration in lactic ferments, under living form or viable, which can be obtained from a fermented milk or yogurt of that tißo with a high concentration in lactic ferments, and without the addition of lactic ferment (s) to the powder. The powder according to the invention responds to the appeal of fermented milk or yogurt. For this purpose, the present invention proposes: the use of at least one strain of S. thermophilus, and at least one strain of L. bulgaricus for fermentation of a lactic substrate, - inoculate the strains with a content considerably higher than that generally used for the manufacture of yogurt, - preferably select strains of S. thermophilus which are the fragile strains, - incorporate at least one strain of L. bulgaricus in a quantity not negligible, to develop a symbiosis S. thermophilus - L. bulgaricus, - to dry fermented milk or yogurt obtained under sufficiently mild conditions to maintain a total population of S. thermophilus and L. bulgaricus of at least 1,107 cfu / L, preferably at least 5,108 cfu / L, more preferably at least 1.1 O 9 cfu / L, and preferably dry the fermented milk or the yogurt obtained just at the powder obtained having a low Aw, preferably lower or equal to 0.3, more preferably less than or equal to 0.25, most preferably less than or equal to 0.2. As described in more detail below, and illustrated with the accompanying comparative examples, the fermented milk powder or yogurt has exceptional preservation capabilities. The metabolic characteristics of the powders according to the invention are at least equivalent to those of the reference yogurts. The powders according to the invention respond to the yoghurt appeal not only by their high contents in ST and LB bacteria in living or viable form, and by the kinetics of acidification that takes place during the lactic fermentation (see example 4 and Figure 4, see example 11), but also for its contents of secondary metabolites, which are at least equivalent to those of a reference yogurt (see example 10). When the process of the invention is continued, and a massive inoculation of the lactic substrate is carried out. This massive inoculation has the effect of leading to a more limited growth in biomass, in relation to cell growth that will be observed during the manufacture of classic yoghurts (classical doses of inoculation, lower than those of the invention). The inventors demonstrate that, contrary to what was anticipated, although cell growth is considerably reduced, the fermentation activity is at least equivalent, or even superior, to that which can be observed during a classic yogurt fermentation. The invention proposes and allows to separate cell growth and fermentation activity. The inventors demonstrate that the metabolic characteristics of the yoghurts, the fermented milks but also the powders according to the invention are at least equivalent, or even superior, to those that can be observed in a classic yogurt. In fact, the inventors demonstrate that for certain secondary metabolites, such as, for example, folates (vitamin B9), the characteristics of the powders according to the invention they are particularly superior to those of the reference yogurts (see example 10). In addition, the metabolic characteristics of the powders according to the invention, and in particular their superior characteristics in vitamin B9, are retained during storage of the powders according to the invention for several months, for example for at least 4 months at 20 ° C (see examples 12 and 13). In comparison, a classic yogurt generally can not be stored for more than 48 hours at 20 ° C without becoming inadequate for consumption. As in particular, it is illustrated in Examples 4 and 10. The invention demonstrates that the fact of proceeding with a massive inoculation of the milk substrate allows not only obtaining a fermentation metabolism according to the exercise of a true symbiosis ST + LB, then although the growth The cellular metabolism is much more limited than that obtained at the classical doses of inoculation, but further demonstrates that the fermentation metabolism thus obtained is at least equivalent, or even superior to that which can be observed during a classic manufacture of yogurt or fermented milk. The invention further demonstrates that the fact of combining this massive inoculation to a soft but deep pulverization of the yogurt or fermented milk that has been obtained by massive inoculation of the lactic substrate, allows to obtain the powders whose storage stability, and in particular the storage stability at room temperature, it is Excellent. In the prior art, there is a bias according to which a deep pulverization, and more particularly a spray up to Aw (water activity) lower, does not allow to obtain satisfactory survival rates for S. thermophilus and L. bulgaricus. According to a preferred embodiment, the invention proposes precisely to contradict this prejudice by means of a gentle but deeper pulverization, and to combine this spraying process with a massive inoculation of the lactic substrate. The present invention relates to a process for the production of yogurt or fermented milk, which allows to obtain a yogurt or fermented milk with high concentration of lactic ferments, without it being necessary to proceed to the addition of lactic bacteria that do not participate in lactic fermentation and / or that would be added later to the inoculation, and without it being necessary to concentrate the fermented dough. The process for the production of yoghurt or fermented milk according to the invention comprises: the inoculation of a lactic substrate, which is eventually subjected to a heat treatment at least equivalent to pasteurization, by inoculation of at least one strain of Streptococcus thermophilus with high concentration, advantageously at a concentration of at least 5108 cfu / g, and at least one strain of Lactobacillus bulgaricus with high concentration, advantageously at a concentration of at least 1.1O6 cfu / g, to obtain an inoculated milk substrate, - the lactic fermentation of the milk substrate thus inoculated, to obtain a fermented milk or a yogurt. The present invention also relates to a process for the production of a fermented milk powder or yogurt, which makes it possible to obtain a powder with high density in lactic ferments, without it being necessary to add the lactic bacteria that do not participate in the lactic fermentation, and more particularly without it being necessary to add the lactic acid bacteria after the initial inoculation of the liquid dairy substrate. The method according to the invention comprises: the inoculation of a lactic substrate, which is optionally subjected to a heat treatment at least equivalent to pasteurization, by inoculation of at least one strain of Streptococcus thermophilus with a high concentration, advantageously with a concentration of at least 5108 cfu / g, and at least one strain of Lactobacillus bulgaricus with high concentration, advantageously at a concentration of at least 1.1O6 cfu / g, to obtain an inoculated milk substrate, - the lactic fermentation of the milk substrate thus inoculated, in such a way that a fermented milk or yogurt is obtained, - the pulverization of the fermented milk or yogurt thus obtained. Advantageously, the spraying is conducted under the conditions, and in particular under the conditions of temperature and / or duration and / or speed, and more particularly of the temperature conditions, which allow to obtain the survival rates of each of the strains of S. thermophilus and L. bulgaricus, such as the powder obtained contains at least one strain of S. thermophilus and at least one strain of L. bulgaricus, in living or viable form, at a concentration of at least 5,108 cfu / g and at least 1.1O4 cfu / g, respectively. According to a preferred embodiment, the spraying of the fermented milk or yogurt is maintained until obtaining a fermented milk powder or yoghurt having an Aw (water activity) less than or equal to 0.3, more preferably less than or equal to 0.25, more preferably less than or equal to 0.2, taking care that the spray conditions, and in particular the temperature conditions applied, are sufficiently favorable for the survival of the strains of S. thermophilus and L. bulgaricus to obtain the survival rates of each of strains of S. thermophilus and L. bulgaricus, in such a way that the powder obtained contains at least one strain of S. thermophilus and at least one strain of L. bulgaricus, in living or viable form, at a concentration of at least 5,108 cfu / g and at least 1.1O4 cfu / g, respectively. To produce a powder with high concentration in lactic ferments, the process according to the invention no longer requires that a lactic acid bacterium be added without participating in the lactic fermentation.

The process according to the invention no longer requires fermented milk or yogurt to concentrate in order to obtain high contents of S. thermophilus and L. bulgaricus as necessary.

The method according to the invention uses at least one lactic substrate, at least one strain of S. thermophilus, and at least one strain of L. bulgaricus. The term "milk substrate", in the present invention, is understood as "milk" in the sense that it is given in the dairy industry, this means a substrate that contains essentially milk and / or components of milk, and whose composition it is such that the lactic fermentation of this milk substrate by means of strains of S. thermophilus and L. bulgaricus leads to a product that can be used for human consumption, and more particularly that responds to the appeal of fermented milk or yogurt. The term "milk substrate" thus covers milk of animal origin in all its forms and in all its variants of composition: skim milk or not, concentrated milk or not, ultrafiltered milk or not, fresh milk or not, milk powder or not , reconstituted milk or not, milk recombined or not, milk enriched with milk constituents or not, milk added or not with agents useful for manufacturing or the quality of the finished product, such as flavoring agents, flavors, sugars, etc. The term "lactic substrate" does not include the meaning of "culture medium". In fact, the term "culture medium" refers to a medium intended to favor and / or stimulate the growth of lactic acid bacteria, and therefore to produce an inoculum of lactic acid bacteria, while the term "milk substrate" refers to to a medium that it is destined to be subjected to a transformation by fermentation, to produce a food intended for human consumption. Thus, of the numerous additives that can be added to a culture medium to stimulate and / or promote the growth of lactic acid bacteria, they can not be added to a dairy substrate for the production of a fermented milk or yogurt. In this particular case: numerous tensio-active agents and / or emulsifiers and / or solubilizing agents and / or detergents, such as polyoxyethylene-sorbitan-20- monooleate (thus known as polysorbate 80m or Tween 80), acids type citrate, acetate, meat extracts, - plant peptones, glycerophosphate. To carry out the process according to the invention, at least one strain of S. thermophilus is inoculated at a high concentration in the lactic substrate. Advantageously, it is inoculated with a concentration of at least 5,108 cfu / g. Preferably, at least one strain of S. thermophilus is inoculated into the milk substrate at a concentration of at least 1109 cfu / g, more preferably at least 2109 cfu / g, and even more preferably at least 2.5109 cfu / g. g, most preferably at least 2.6,109 cfu / g, even more preferably at least 2.7109 cfu / g. Preferably, at least one strain of S. thermophilus is inoculated into the milk substrate at a concentration of between 1109 cfu / g and 11010 cfu / g (limits included). To carry out the process according to the invention, at least one strain of L. bulgaricus is inoculated on the lactic substrate. Advantageously, it is inoculated into the milk substrate with a concentration of at least 1.1O6 cfu / g. preferably, at least one strain of L. bulgaricus is inoculated in the milk substrate with a concentration of at least 1107 cfu / g, preferably at least 1107 cfu / g, more preferably at least 1.2107 cfu / g, even more preferably at least 1.3107 cfu / g, still more preferably at least 1.4107 cfu / g. Preferably, at least one strain of L. bulgaricus is inoculated into the milk substrate at a concentration between 1,107 cfu / g and 5,108 cfu / g (limits included). Once the dairy substrate is inoculated with a high concentration of the at least one strain of S. thermophilus and with a high concentration of the at least one strain of L. bulgaricus, the lactic fermentation is conducted according to known techniques. the expert in the art, to obtain a product that responds to the appeal of fermented milk or yogurt. The inoculated milk substrate is maintained under the conditions, and in particular the temperature conditions, favorable to the fermentation activity of at least one strain of S. thermophilus and at least one strain of L. bulgaricus, until a fermented milk or yogurt is obtained. The initial pH of the milk substrate is generally between 8 and 6, and drop approximately two to four pH units, and obtain, at the end of the lactic fermentation, a final pH that is generally comprised between 5 and 4 (generally, pH of 4.7-4.6 for yoghurts). In the present invention, all terms have the meaning generally given to them in the dairy industry and / or in the food industry. Thus, when reference is made to a «lactic fermentation», it is an acidifying lactic acid fermentation, which is acidification followed by the production of lactic acids that can be accompanied by the production of other acids, carbon dioxide, and of various substances such as exopolysaccharides (EPS) or aromatic substances, for example diacetyl and acetaldehyde. Likewise, with «lactic ferment», a microorganism or a strain of living or viable microorganisms, which is capable of producing an acidic lactic acid fermentation on a lactic substrate. The terms "fermented milks" and "yoghurts" are given their usual meanings in the field of dairy industry, that is, the products that are intended for animal consumption, and more particularly human, and that their result of lactic fermentation Acidifier of a lactic substrate. These products may contain secondary ingredients such as fruits, vegetables, sugars, aromas, etc. The appeal of "fermented milk" and "yoghurts" responds to strict official standards. This can be reported in the Food Code (prepared by the Food Code Commission under the sponsorship of FAO and WHO, and published by the FAO Information Division, available online at http://codexalimentarius.net; see more particularly, volume 12 of the Food Code "Code Standards for milk and milk products", and the standard "CODEX STAN A-11 (a) -1975", filed under the reference CODEX STAN 243-2003). More particularly, reference can be made to French Decree No. 88-1203 of December 30, 1988 concerning fermented milk and yogurt, published in the Journal Officiel de la République Francesa of December 31, 1988. The contents of this Decree are incorporated by reference in the present patent application. Thus, a yogurt no longer contains lactic bacteria other than S. thermophilus and L. bulgaricus, so a fermented milk may also contain bacteria from those two species. The term "fermented milk" in the present invention refers to a dairy product prepared with a dairy substrate that is subjected to a treatment at least equivalent to pasteurization, inoculated with the microorganisms belonging to the species or to the characteristic species of each product. . The The coagulation of "fermented milks" does not have to be obtained by means other than those resulting from the activity of the microorganisms used. The term "yogurt" (or "yogurt") is reserved to the fermented milk obtained, according to the loyal and constant uses, by the development of specific thermophilic lactic bacteria Lactobacillus bulgaricus (also called Lactobacillus delbrueckií ssp. Bulgaricus) and Streptococcus thermophilus, which must be found alive in the final product, in a proportion of at least 1.1O7 ufe of S. thermophilus and L. bulgaricus bacteria per gram of product, with respect to the milk part of this product.

A product that responds to the yoghurt appeal will then compulsorily contain at least one strain of S. thermophilus and at least one strain of L. bulgaricus in live form, in a proportion of at least 1,107 cfu / g of milk part.

The coagulation of «yoghurts» does not have to be obtained by means other than those resulting from the activity of the microorganisms used. A "fermented milk" or a "yogurt" is not subjected to any treatment that allows to remove an element constituted from the milk substrate used, and in particular it is not subjected to a drainage of the clot. A "fermented milk" or a "yogurt" can be added with one or more aromatic extracts, one or more natural flavors, as well as, in the limit of 30 to 100 by weight of the finished product, one or several sugars and other food products that confer a specific flavor, or even cereals. The introduction of substitution products of fatty and / or protein materials of non-dairy origin is prohibited. The amount of free lactic acids contained in a fermented milk can not be less than 0.6 gram per 100 grams during sale to the consumer, and the content of protein material in relation to the milk part can not be less than that of a milk normal. The amount of free lactic acids contained in a yogurt can not be less than 0.7 grams per 100 grams during sale to the consumer. According to the present invention, fermented milk or yogurt produced by inoculation of at least one strain of S. thermophilus and at least one strain of L. bulgaricus will contain those strains at a concentration slightly higher than that of their inoculation. A fermented milk or yogurt produced according to the present invention may then contain: - at least one strain of S. thermophilus with a concentration of at least 5,108 cfu / g, preferably at least 1,109 cfu / g, more preferably at least 2,109 cfu / g, and even more preferably at least 2,5109 cfu / g, more preferably at least 2.6109 cfu / g, still more preferably at least 2.7109 cfu / g, and - at least one strain of L. bulgaricus with a concentration of at least 1,107 cfu / g, more preferably at least 1, 1,107 cfu / g, more preferably at least 1, 2,107 cfu / g, even more preferably at least 1, 3,107 cfu / g, still more preferably at least 1, 4,107 cfu / g. Preferably, a fermented milk or yogurt produced in accordance with the present invention will contain: - at least one strain of S. thermophilus with a concentration between 1,109 cfu / g and 1,1010 cfu / g (limits included), and at least one strain of L. bulgaricus with a concentration between 1,107 cfu / g and 5,108 cfu / g (limits included). A yogurt or fermented milk according to the invention comprises a high density in ST and LB in living or viable form (contained in ST and LB under living form such as described in the application, for example a content of living ST higher or equal at 5,108 cfu / g and a live LB content greater than or equal to 1,107 cfu / g). According to a particular embodiment of the invention, the yoghurt or fermented milk produced also has a high content of dry matter. In the present invention, the dry matter content, or MS content, corresponds to the mass of residual material measured after having placed the product at 105 ° C for 17 hours, in relation to the initial volume or the initial mass of the product. An MS content can be measured directly, this means placing the product when you want to know the DM content for 17 hours at 105 ° C, and measuring the mass of residual matter that contains the initial volume of the product thus treated. An MS content can be measured indirectly, this means by measuring a parameter of the product from which the MS content can be deduced or estimated. For example, the person skilled in the art can measure the density of the product at a given temperature (for example, at 45 ° C), and deduce the corresponding MS content, for example with the help of a table or a correspondence curve which has been pre-established by the person skilled in the art, to deduce the measure of the density at a given temperature, the corresponding MS value for the product under consideration. In products, such as the starting milk substrate, indirect measurements such as densitometry are generally preferred, since they are faster to use in the direct method. A classic dairy substrate has an MS content in the order of 10-20%, for example 11-13%. A yogurt or a fermented milk obtained by lactic fermentation of a conventional dairy substrate of that type have MS contents that are not essentially different from those of the initial milk substrate, this means a classical MS content in the order of 10-20% . For the use of the invention, a milk substrate can be used with classic MS content. According to a particular embodiment of the invention, yoghurts or fermented milks are produced which, in addition to having high contents in ST and LB as indicated in the present invention, have a higher MS content than the classical MS content, and more particularly an MS content greater than or equal to 25%, for example 25-60%, preferably greater than or equal to 28%, for example 28-55%, more preferably greater than or equal to 30%, for example 30 -45%, more preferably 36-40%. In order to produce such yoghurts or fermented milks, it is convenient to inoculate ST and LB to the contents according to the invention in a dairy substrate where the MS content is essentially different or approximate to that required for the yogurt or fermented milk that would result from the lactic fermentation. of this substrate so that the product obtained by lactic fermentation always responds to the appeal of yogurt or fermented milk, it is obviously convenient not to use a milk substrate whose MS content would be so high that the fermented product obtained would no longer correspond to the definition of a yogurt or fermented milk, but they are closer to dairy products such as, for example, cheeses. It is then recommended to select a milk substrate whose MS content does not exceed 60%, preferably 55%, more preferably 45%. Thus, according to a particular embodiment of the invention, the dairy substrate used it may have an MS content of 25% -60%, preferably 28% -55%, more preferably 28-45%, still more preferably in the order of 30-45%, most preferably 36-40%. To increase the DM content of the yogurt or fermented milk, without the product losing its appeal of yogurt or fermented milk, it is possible to proceed to concentrate the dairy substrate on which the ST + LB fermentation is to be carried out according to the invention . Thus, before the inoculation of ST and LB, the lactic substrate can be concentrated, for example by removing a part of the water contained in the lactic substrate. This elimination of the water can for example be carried out by evaporation, for example by heating the milk substrate until the desired MS content is obtained. The milk substrate can thus be placed at one of the temperatures in the order of 40-90 ° C, for example by subjecting the dairy substrate to a temperature gradient of about 90 ° C to about 50 ° C or 40 ° C, as is the case, for example, when industrial evaporators are used. For safety, at least a sanitary treatment of the milk substrate can precede this concentration stage, and / or be carried out after the concentration stage but before the inoculation of the ST and LB bacteria. A sanitary treatment of this type is a treatment of the dairy substrate intended to sanitize or stabilize, destroy or inhibit all or a part of the agents microbials that can contain the lactic substrate, and more particularly the assembly of the microbial agents that can cause health problems in the consumers, and preferably all or a part of the microbial agents that can lead to the degradation of the food itself. Examples of such sanitary treatments comprising, for example, a heat treatment at least equivalent to pasteurization (for example, treatment at least equivalent to the application of a temperature of at least 72 ° C for at least 15 seconds, such as a temperature 90 ° C for 30 seconds before the concentration of the substrate and / or temperature of 75 ° C for 15 seconds after the concentration of the substrate). To increase the DM content of the yogurt or fermented milk, without losing the product's appeal of yogurt or fermented milk, it is possible to add to the dairy substrate destined to be fermented at least one compound having a part of DM. As the product that is going to be produced must respond to the appeal of yogurt or fermented milk, the CODEX STAN A-1 1 (a) -1975 (referred to under CODEX STAN 243-2003) and / or Decree n. 88-1203 of the French Republic, to verify that the compound or compounds intended to constitute a part of MS are compatible with the definition of yogurt or fermented milk. Thus, it will be avoided to select a compound that can modify the texture and / or the structure of the dairy substrate in a very substantial way, in such a way that the fermented product obtained has the structure and texture of a yogurt or fermented milk. A compound is preferably a product derived from milk. A compound of that type will preferably be low in protein, to limit coagulation problems. Advantageously, a lactose-containing compound is selected, preferably a lactose-rich compound, such as milk whey. Advantageously, the demineralized or sweet whey (pH of approximately 6.5), without removing the lactose. If at least one aggregate compound such as the MS part is in solid form, it represents a direct part of MS. On the contrary, if at least one compound added by way of the MS part is in liquid form, it is convenient to take into account the fact that the MS, this compound also contributes the water in such a way that the resulting MS content It can not be higher than the initial milk substrate. This is for example generally the case when one chooses to add the milk whey in liquid form to the initial milk substrate. In such a case, the addition operation of the MS-contributing compound must be performed by a concentration operation of the dairy substrate by removing a part of the contained water, as described below, for example by an evaporation operation. It will be ensured that at least one compound added to title of part of MS is, or has been treated so that it is free of any microbial agent that can cause problems to the health of consumers and, preferably of any microbial agent that may cause the degradation of the food itself. Such sanitary treatments include in particular a heat treatment at least equivalent to pasteurization (for example, treatment at least equivalent to the application of a temperature of at least 72 ° C for at least 15 seconds, such as a temperature of 90 ° C during 30 seconds before substrate concentration and / or temperature of 75 ° C for 15 seconds after concentration of the substrate). An example of embodiment of the particular embodiment of the invention comprises: a) the treatment of a milk substrate (whose composition is such as to allow this substrate to respond, after lactic fermentation, to the appellation of yogurt or fermented milk) , such that it reaches a DM content greater than or equal to 25% and less than or equal to 60%, preferably greater than or equal to 28% and / or less than or equal to 55%, more preferably greater than or equal to 30% and / or less than or equal to 45%, more preferably of 36-40%, without losing its ability to respond, once fermented, to the appellation of yogurt or fermented milk, the dairy substrate thus treated is a dairy substrate with a high content of MS, this treatment of the milk substrate can be for example performed by: i. concentration of the MS of the lactic substrate, for example eliminating a part of the water it contains, for example by evaporation, and / or by ii. addition to the dairy substrate of at least one compound that is intended to provide the MS to the dairy substrate to be fermented, and whose nature is such that it does not deprive the dairy substrate of its ability to respond, once fermented, the yoghurt appeal or fermented milk, b) optionally, the sanitary treatment of the dairy substrate with a high MS content, to sanitize or stabilize, destroy or totally or partially inhibit the microbial agents that it may contain, and more particularly the assembly of microbial agents that can causing health problems in consumers, and preferably all or part of the microbial agents that can cause the degradation of the food itself, for example by treatment of the substrate by heat treatment at least equivalent to pasteurization (for example, treatment at least equivalent to the application of a temperature of at least 72 ° C for at least 15 seconds, for example the temperature of 90 ° C for 30 seconds), c) the inoculation of the dairy substrate with a high content of MS, which is eventually subjected to the sanitary treatment of step b), for at least one strain of ST and at least one strain of LB at high contents, according to the invention, as described in the present invention, d) the carrying out the lactic fermentation until obtaining yogurts or fermented milk (for a yogurt, the pH that marks the end of fermentation is generally 4.8 + 0.5 / -0.3 pH units, for example pH = 4.8 + 0.4 / -0.3, for example pH = 4.8 +/- 0.3 pH units, for example pH 4.8 +/- 0.2 pH units preferably pH 4.8 + 0.5 / -0.1, for a fermented milk different from yogurt, the pH indicating the end of the fermentation is generally 4.6 +/- 0.2 pH units), e) the yoghurts or fermented milks obtained then of the yogurts or fermented milks with high contents in ST and LB and with a high content of DM, according to the invention, f) if necessary, the pulverization of the obtained yoghurts or fermented milks, to obtain a powder in which the ST and LB populations under living or viable form are in accordance with the invention, as described in the application . The method can also comprise one or several sanitary treatments of the product in question (that is to say applied to the milk, at least one MS-contributing compound and / or to the substrate or milk "mixture"), at the moment in which the expert in the art, consider appropriate, for example, before and / or after step b), and / or before step c). Such sanitary treatment is intended to destroy or inhibit all or part of the microbial agents that this product may contain, and more particularly the set of microbial agents that can cause health problems in consumers, and preferably all or part of the microbial agents that can cause the degradation of the food itself, for example by means of heat treatment at least equivalent to pasteurization (for example, treatment at least equivalent to the application of a temperature of at least 72 ° C for at least 15 seconds, for example temperature of 90 ° C for 30 seconds). A particular example of the embodiment "yoghurt with a high MS content" of the invention is presented in example 12. Once obtained, yogurt or fermented milk with high contents in ST and LB and with high MS contents according to the invention it can be sprayed as described in the application, until obtaining Aw (water activity) low, preferably until obtaining an Aw less than or equal to 0.3, preferably less than or equal to 0.25, preferably lower or equal to 0.2, as described below. The drying must be efficient enough to obtain the value of Aw necessary, and soft enough to conserve the maximum of ST and LB bacteria in living or viable form. In order to carry out this spraying, the procedure described in the application for yoghurts having a classical MS content will be followed, for example with the aid of an atomization device corresponding to the scheme presented in FIG. 3, and / or as described in FIG. example 3. Another example of drying is also presented in example 9.

The fermented milk or yogurt obtained by lactic fermentation is then pulverized under conditions that allow obtaining certain survival rates of each of the strains of S. thermophilus and L. bulgaricus. The pulverization of a fermented milk or a yogurt destroys the integrity of the membrane, and more generally, kills a part of the lactic bacteria present in the fermented milk or yogurt. At the same time, spraying leads to a concentration of lactic acid bacteria content, to the extent that a powder consists of 95 to 99% dry mass, while fermented milk or yogurt is a moist mass, representing the mass dry in general 15 to 20% of its total mass. Preferably, the spray is maintained in such a way that at least one strain of S. thermophilus is contained in the powder according to the invention in living or viable form with a content of at least 5108 cfu / g, more preferably at least 1109 cfu / g, still more preferably at least 2,109 cfu / g, more preferably at least 3,109 cfu / g. Preferably, the spray is maintained so that the at least one strain of S. thermophilus is contained in the powder according to the invention in living or viable form with a content between 1109 cfu / g and 11010 cfu / g (limits included). Preferably, the spray is maintained so that at least one strain of L. bulgaricus is contained in the powder according to the invention in living or viable form with a content of at least 1,104 cfu / g, preferably at least 2,104 cfu / g, preferably at least 3,104 cfu / g, more preferably at least 4,104 cfu / g, even more preferably at least 8,104 cfu / g, most preferably at least 1,105 cfu / g, still more preferably at least 3,105 cfu / g. Preferably, the spray is maintained so that at least one strain of L. bulgaricus is contained in the powder according to the invention in living or viable form with a content between 1,104 and 1,105 cfu / g. All combinations of S. thermophilus content and content of L. bulgaricus are included in the content of the present patent application. For example, and advantageously, the fermented milk or yogurt obtained can be pulverized under conditions that allow obtaining a survival rates of each of the strains of S. thermophilus and L. bulgaricus, as the obtained powder contains the at least one strain of S. thermophilus with a concentration of at least 5,108 cfu / g, preferably at least 1,109 cfu / g, and the at least one strain of L. bulgaricus, in living or viable form with a concentration of at least 1,104 cfu / g , preferably at least 4,104 cfu / g, respectively. Survival rates of at least one strain of S. thermophilus and at least one strain of L. bulgaricus depends on the nature of the strains, the type of spray procedure used, and the conditions, more or less mild, under which this procedure is applied. The pulverization of the fermented milk or yogurt will be soft enough to ensure the best preservation of each of the lactic fermeinoculated in living or viable form. Advantageously it can be carried out by atomization with a gaseous flow temperature (air) such that the temperature of the product (powder) does not exceed 80 ° C, for example a gaseous flow temperature (air) of 190-210 ° C. Advantageously, this atomization is associated with a complementary drying of the granules on a fluid bed; for example, an internal fluid bed in the lower part of the atomization loop. Advantageously, the gaseous flux temperature (air) for the fluid bed (= outlet temperature, if the bed is inside and below the turn) is less than or equal to 100 ° C, preferably less than or equal to 80 ° C , more preferably from 6 ° C to 8 ° C, advantageously from about 70 ° C (see example 3 below, and figure 3). In the context of the present invention, the spray preferably has a yield of at least about 20% as regards the at least one strain of S. thermophilus, preferably at least 25%, more preferably at least 30%. %, Y at least 2.10"5% for the L. bulgaricus strain, preferably at least 5.105%, more preferably at least 0.1%, more preferably at least 0.5% .The spraying of the fermented milk or yogurt is maintained at drying conditions sufficiently intense to produce a fermented milk powder or yogurt that has a low Aw (water activity). Advantageously, the spraying of the fermented milk or yogurt is maintained under the drying conditions leading to a fermented milk powder or yoghurt which, upon leaving the spray, has an Aw (water activity) measured at room temperature. (temperature of 20-26 ° C, for example 25 ° C), which is less than or equal to 0. 3, preferably less than or equal to 0.25, more preferably less than 0.25, advantageously less than or equal to 0.2. Preferably, the Aw will be greater than or equal to 0.05, preferably greater than or equal to 0. 09. According to a preferred embodiment of the invention, this Aw will be 0.05-0.25, preferably 0.05-0.20. more preferably from 0.09-0.19 for example from 0.10-0.19. The pulverization of the fermented milk or yogurt is done by drying and physical transformation in the form of granules (= granulation). The pulverization conditions are then the physical parameters that are applied to the fermented milk or yogurt to obtain the necessary drying and granulation.

The adjustment of the parameters applied during the spraying to obtain the necessary survival rates and the necessary Aw value can be obtained by the person skilled in the art if he makes the adjustments that can be made by trial and error with the help of the general knowledge of the expert in the art. technique These parameters should have a sufficiently smooth effect on the cells of S. thermophilus and L. bulgaricus to have the necessary survival rates, and at the same time have a sufficiently deep effect to obtain the necessary Aw value. An essential parameter against the survival of the cells of S. thermophilus and L. bulgaricus is the temperature (or temperature gradient) applied to dry fermented milk or yogurt. If the spray includes an evaporation of the water, the skilled person can select a sufficiently low temperature (or a low or mild enough temperature gradient) to obtain the necessary survival rates. If the spray includes sublimation of water, the skilled person can select a high enough temperature (or a sufficiently low or mild temperature gradient) to obtain the necessary survival rates. It will then be convenient to apply these temperatures (or this radiant temperature) for a sufficiently long time to obtain the necessary Aw value. The person skilled in the art can then adjust these temperature parameters and the duration to obtain the objective of Survival and Aw contemplated. If the spraying is done by atomization, the drying and granulation are carried out together in the spray tower. If the spraying is carried out by lyophilization, it is then dried by lyophilization, then the pulverization of the paste obtained at the exit of the lyophilization, to transform this paste into powder granules. If needed or required, the spraying may comprise one or more complementary dryings, for example drying on a fluid bed and / or on a vibrating bed. Preferably, these complementary drying is carried out at a temperature of 25-80 ° C. One of these complementary dryings can in particular be required when the granules obtained after the atomization, or, if necessary, at the exit of the lyophilization-granulation, have the required survival rates, but the necessary Aw value is not obtained. It is then possible to place the powder granules under the lower temperatures, which will complete the drying of the granules until obtaining the necessary Aw value, without lowering the contents of S. thermophilus and L. bulgaricus beyond the minimum required contents. Assuming that at this stage, the granules were already formed, the temperatures applied for the complementary drying may be lower, for example 25 ° C-90 ° C. For example, spraying can be done by lyophilization and granulation of the lyophilization paste, and may further comprise a complementary drying on an external bed, for example an external vibrating bed. For example, spraying can be carried out by atomization (preferably taking care that the temperature of the product does not exceed 80 ° C), and further comprising a drying on a fluid bed of the powder granules that have been obtained by atomization. This fluid bed is preferably an internal fluid bed, in the lower part of the atomization tower. This complementary drying on a fluid bed can advantageously be followed by drying on an external bed, for example an external vibrating bed (preferably at a temperature close to room temperature, for example 25-40 ° C). This type of complementary drying is a preferred embodiment of the invention. According to a preferred embodiment of the invention, the spray comprises, in addition to the drying applied to form the powder granules, one or several complementary dryings that are applied to already formed powder granules.

In fact, the inventors have observed that it is more efficient to form powder granules that have the necessary survival rates, but without completely removing the contained water, this means they approach but without obtaining the necessary Aw value, to stabilize the bacteria S Thermophilus and L. bulgaricus are contained without subjecting them to too high a tension, and drying is followed by drying complementary to the granules, preferably at a temperature of 25 to 85 ° C, for example on a fluid bed advantageously, with an air temperature of 60 to 80 ° C) and / or on a vibrating bed (advantageously, at a temperature of 25-4 ° C). According to a preferred embodiment of the invention, granulation is carried out by atomization, and drying is drying at three points, such as: spray by atomization (preferably, taking care that the temperature of the product does not exceed 80 ° C ), and - drying on a fluid bed of the powder granules which have been obtained by atomization, this fluid bed is preferably an internal fluid bed, in the lower part of the atomization tower, this first complementary drying is followed by drying on external bed, for example an external vibrating bed (preferably at a temperature of about room temperature, for example 25-40 ° C). Examples of powder production according to the invention are described in example 1, and advantageous examples of pulverization are described in examples 3 and 9. The powder according to the invention has better preservative properties: the powder according to the invention retains its initial appearance both in terms of color and texture, as well as taste qualities, during the storage of the powder for at least 4 months at 20 ° C. In addition, the rates of S. thermophilus and L. bulgaricus that are contained in the powder under living or viable form remains elevated over time. The fermented milk powder or yoghurt according to the invention retains at least 1,107 cfu / g of live or viable lactic ferments (total population in lactic ferments S. thermophilus and L. bulgaricus), after preservation of this powder for six months at 20 °. C, without and having ajout of S. thermophilus or L. bulgaricus. Advantageously, the powder according to the invention does not suffer any detectable loss in S. thermophilus in relation to the fermented milk or yogurt d where it comes, after a storage of 4 months, or even longer, at a temperature of 20 ° C.

The fermented milk powder or yogurt according to the invention advantageously retains: at least 5,108 cfu / g, more preferably at least 1,109 cfu / g, from the at least one strain of S. thermophilus in living or viable form, and - when at least 1,104 cfu / g of the at least one strain of L. bulgaricus in living or viable form, preferably at least 2,104 cfu / g, preferably at least 3,104 cfu / g, more preferably at least 4,104 cfu / g, more preferably at least 8,104 cfu / g, more preferably at least 1,105 cfu / g, still more preferably at least 3,105 cfu / g of the at least one strain of L. bulgaricus in living or viable form, after preservation of this powder at 2 ° C for four months, or even more, without the addition of S. thermophilus or L. exogenous bulgaricus. Advantageously, at the end of 4 months at 20 ° C, the powders of the invention are at least 2,108 cfu / g of total population S. thermophilus and L. bulgarícus in living or viable form. More generally, this total population is at least 3.5.10e cfu / g, more frequently at least 4108 cfu / g. This is in particular the case when the milk substrate used to produce the yogurt or fermented milk has a classical MS content, this means an MS content of 10 to 20%, for example 11-13%. In a particularly remarkable manner, according to an embodiment of the invention, the survival rates of the total population S. thermophilus and L. bulgaricus content of a powder of the invention is at least 80% at the end of 4 months of storage of the powder at a temperature of 20 ° C. This is in particular the case when the milk substrate used to produce the yogurt or fermented milk has a classical MS content, this means an MS content of 10 to 20%, for example 11-13%. More advantageously, at the end of 6 months at 20 ° C, the powders of the invention comprise more than 1, 0.107 cfu / g of total population S. thermophilus and L. bulgaricus in living or viable form, most generally at least 5,107 cfu / g. Frequently, this total population is at least 1,108 cfu / g, more frequently at least 4,108 cfu / g. This is particularly the case when the dairy substrate used to produce the yogurt or fermented milk has a classic MS content, this means an MS content of 10 to 20%, for example 11-13%. In a particularly remarkable manner, according to one embodiment of the invention, the survival rates of the total population S. thermophilus and L. bulgaricus contained in a powder of the invention is at least 75%, most generally at least 85%. %, at the end of 6 months of storage of the powder at a temperature of 20 ° C. This is particularly the case when the milk substrate used to produce the yogurt or fermented milk from which the powder comes is a milk substrate with a classical MS content (10-20%). The meaningful term is understood here in its statistical sense, and to the extent understood within the framework of the dairy industry. The term "significantly" is used here with its usual meaning in the domain of statistics (for example, t-test, z-test, chi-square value, F-ratio, etc.), that is, to compare one measured value of another, and determine if these measured values differ from each other. The term "significantly" consequently encompasses the fact that the person skilled in the art can take into account the type of deviation (if any), which measures the dispersion of the data in a frequency distribution. The desired value of p is usually placed at an alpha level of 5%, or at the most rigorous level of alpha of 1%. To the knowledge of the applicant, the technical powders above do not have good preservation properties (see examples 12 and 13 below). Of the means that allow to measure the rates of S. thermophilus and L. bulgaricus that are contained in living or viable form in the powder are known to the person skilled in the art including in particular the official method FIL 117B: 1997, Yogurt: enumeration of the characteristic microorganisms, colony counting technique at 37 ° C. The powder, or if appropriate, the filler, to be analyzed can be prepared as described in example 5 below. The strains of S. thermophilus and L. bulgaricus can be selected from those known to the person skilled in the art because they are suitable for a lactic fermentation on the lactic substrate, in such a way that it produces a fermented milk or a yogurt. An example of a strain of S. thermophilus is the strain available in C.N.C.M. under the deposit number 1-2130 (deposit date before the C.N.C.M. = February 24, 1999, depositor = Compagnie Gervais-Danone). An example of a strain of L. bulgaricus is the strain available before the C. N. C. M. under the deposit number 1-1519 (date of deposit before the C.N.C.M. = 30 December 1994, depositor = Compagnie Gervais-Danone). It is preferably selected at least one strain of S. thermophilus and / or at least one strain of L. bulgaricus that has a capacity of propagation on dairy substrate that can produce the inoculation ferments with high density, and more particularly of the ferments whose population of S. thermophilus and L. bulgaricus is: - equal to or higher than 3.1010 cfu / g of S. thermophilus, equal to or greater than 1.1O9 cfu / g of L. bulgaricus, for ferments in frozen form, or - equal to or greater than 1,1011 cfu / g of S. thermophílus, equal to or greater than 4,109 cfu / g of L. bulgaricus, for the ferments in lyophilized form. The population of S. thermophilus and L. bulgaricus can be prepared and / or conditioned separately, or they can be mixed. They can be contained in different granules, or they can be contained in the same granule that provides the types of two populations. Advantageously, and contrary to the usual method for manufacturing a fermented milk or yogurt, preferably they will be selected from at least one strain of S. thermophilus that produces little or no EPS exopolysaccharides (strain of the fragile type).

Preferably, the at least one strain of S. thermophilus is a strain of the fragile type, which does not produce exopolysaccharide (EPS), or which is produced in contents as low as milk-based medium, after cultivation of this strain to a temperature of 40 ° C to a pH of 4.7, has a Casson viscosity at 4 ° C which is less than or equal to 500 mPa.s, preferably less than or equal to 400 mPa.s.

A milk-based medium suitable for such a viscosity measurement may simply be milk, or a model fermented milk medium, such as, for example, a medium composed of 120 grams of skimmed milk powder, 1 gram. of peptide N3 (Vitalarmor 950. Armor proteines), and water to form 1L. Example 6 below presents a detailed example of the protocol. Of the classical doses of inoculation of S. thermophilus can be used (for example, inoculation at 1% v / v), such as those presented in example 6. An example of a strain of S. thermophilus (S. thermophilus Fragile type) is the strain of S. thermophilus available before the CNCM. under the deposit number 1-2130. To select a strain of lactic ferment that does not produce or produce exopolysaccharides (EPS), it may be a procedure known to the person skilled in the art. An adapted methodology comprises the measurement of the viscosity of the fermented milk obtained by fermentation of a dairy substrate with the help of the candidate strains, such as for example a yogurt produced with the help of the candidate strains. One method allows to determine if the strains used for the fermentation of the milk give a fermented milk a filamentous texture (important viscosity), if they are of the textured type (medium viscosity), or if they produce a fermented milk to a texture fragile (low viscosity). Within the framework of the present invention, and contrary to those processes used manufacturing of fermented milk and yogurt that are not intended to be powdered, the preferred lactic derivatives are those that provide a fermented milk with a brittle texture (low viscosity). The method for measuring the viscosity of a fermented milk comprises the use of a cooled viscometer and equipped with a system that allows to apply a growing and decreasing gradient of tearing to the fermented milk, such as the cooled Mettier RM® 260 viscometer and equipped with a coaxial system of type DI N 145. This rotary system allows observing a destructuring of the product as a function of a linear tear gradient, that is, a difficulty at a given gradient. Briefly, this method comprises: the cultivation of the candidate lactic acid (s) on an appropriate culture medium, such as a milk-based medium (milk, fermented milk medium, see example 6), after cultivation of this strain at a temperature of 40 ° C to a pH of 4.7, it has a Casson viscosity at 4 ° C which is less than or equal to 500 mPa.s, preferably less than or equal to 400 mPa.s, [if required, several batches of fermented milks under identical conditions can be products to have several comparable specimens], - if the model fermented milks obtained are one of the closed products, these fermented milks are preferably stirred manually with the help of a spatula during a minute, - incubation at 4 ° C for 30 min of the fermented media, or at least one sample taken from these fermented media, - the viscosity measurements are made at 4 ° C, with the help of a Mettier RM® 260 viscometer cooled and equipped with a coaxial system of the DIN 145 type. A milk-based medium suitable for such a viscosity measure may be simply milk, or a model fermented milk medium, such as, for example, a compound medium of 120. grams of skim milk powder, 1 gram of N3 peptide (Vitalarmor 950. Armor proteines), and water to form 1 L. Example 6 presents a detailed example of the protocol. Classical inoculation doses of S. thermophilus (eg, 1% v / v inoculation) can be used, such as those presented in Example 6. The production is subjected to an increasing tear gradient of 0 to 20 s- 1 for 1 minute. This phase corresponds to the ascending ramp. Then, it is subjected to a decreasing tear gradient of 20 to 0 s -1 for 1 minute, corresponding to the descending ramp. The results are obtained in the form of a continuous flow curve, with ascending ramp and descending ramp between 0 and 20 s-1. Figure 1 shows the three main types of flow curves: - the type of curve obtained with the help of the strain S. thermophilus 001 010 corresponds to a strain that gives milk fermented to filamentous texture (significant viscosity, upper curve), - the type of curve obtained with the help of the strain S. thermophilus 001 098 corresponds to a strain that is of the textured type (medium viscosity, middle curve), - the type of curve obtained with the help of strain S. thermophilus TS 10B (DSM Food specialties Dairy agents; BP 1; 2600 MA Delft; Netherlands) corresponds to a strain that gives a fermented milk a fragile texture (low viscosity , curve down). The tangent at any point of the descending ramp flow curve represents the apparent viscosity of the fermented medium. This apparent viscosity varies according to the tear gradient considered, and it is preferable to adjust the curve by a mathematical model. Various suitable mathematical models are known to the person skilled in the art. The Casson model is an example of an appropriate model. The viscosity of the fermented milk (?) Is derived from the slope of the regression line of the descending part (descending tear gradient) of the obtained flow curve, modified to represent the square root of the difficulty as a function of the root square of the tear gradient. Due to the heterogeneity of certain fermented milks (in particular, of closed products, which must be mixed manually), and of the conception of certain viscosimeters, in addition it is necessary to eliminate the incoherent points of measurement before the formation of mathematical models, such as for example the incoherent points that can be obtained during a possible pinion change intended to increase the tearing speed. It is also necessary to eliminate a part of the ascending curve corresponding to the transient regime of laminar flow of the product within the air gap. The adjustment is preferably made on the downward curve, or the points associated with the thixotropy of the product and the flow rate are less important. The Casson model is formulated by the following equation (equation 1): t: difficulty (Pa) r0: Maximum flow limit of the product (Pa)? : Product viscosity (Pa.s) D: Tear gradient (s-1) This modeling followed by the plotting of a linear regression line on the descending part of the curve; which allows to indicate two important parameters: - the maximum flow limit of the product t0 corresponding to the order of origin, - the viscosity of Casson? of the product, corresponding to the slope of the regression line. Figure 2 illustrates the determination of the maximum flow limit To and of the viscosity? of a fermented milk with the help of strain 001 098, on the descending flow curve modeled by Casson. Beyond 500 mPa.s, it is considered that the Casson viscosity of the fermented milk is medium or strong, this means that the strain (s) tested are of the clearly textured type, or else they confer a filamentous texture. When the Casson viscosity measured is equal to or less than 500 mP C a.s, the Casson viscosity is considered low, this means that the tested strain (s) confer a fragile texture. Preferably, strains whose Casson viscosity at 4 ° C is equal to or less than 400 mPa.s. In the prior art, in order to produce a yogurt of real nutritional quality, strains of S. thermophilus textured (strong producers of EPS) are preferably selected, to obtain a yogurt having a texture and a flavor satisfactory to the consumer. The presence of strains of S. thermophilus of the fragile type will, however, be generally equally necessary, insofar as the sanitary safety makes it possible to obtain an acidification of the milk substrate as quickly as possible. Thus selecting an appropriate combination of strains of S. thermophilus of the fragile type and strains of S. thermophilus texturized, that can be produced a yogurt that has a real nutritional quality, both in the plane of the texture, as the flavor, and as in regard to health security. In the present invention, the contrary to preference, strains of S. thermophilus of the fragile type, avoiding the use of the texturized type. Furthermore, in accordance with the present invention, it is not necessary to obtain a quality finished product (powder product), to use a combination of strains of S. thermophilus, it is otherwise possible to limit the number of different strains of S. thermophilus (one, two or three strain (s) of S. thermophilus), as well as the number of L. bulgarice (one, two or three strain (s) of L. bulgaricus). The process according to the invention makes it possible in fact to obtain a high quality powder using a single strain of S. thermophilus (and at least one strain of L. bulgaricus). This strain of S. bulgaricus is preferably of the fragile type. According to the present invention (process for the production of yoghurt or fermented milk, process for the production of powder, ferments, inoculated milk substrate, fermented milk or yogurt obtained, fermented milk powder or yogurt obtained, food, such as filling, bread, sweets), can use a single strain of S. thermophilus, which is preferably a strain of the fragile type, and, preferably, a single strain of L. bulgaricus is used. The powder according to the invention can have any suitable granulometry. A granulometric distribution of between 10 and 300 microns is preferably selected for an application in the dairy or bakery or confectionery industry. The present invention also relates to starting products, intermediates and final products which can be used or obtained by the use of a method according to the invention. Each of the characteristics given in the present invention in the description of the process according to the invention can be applied mutatis mutandis to starting materials, intermediate products and final products of the invention. A starting product that can be used in a process according to the invention consists of one or two concentrated ferments of lactic acid bacteria. The concentrated ferment (s) make it possible to easily provide the important doses of inoculum required by the process according to the invention. The concentrated ferments according to the invention comprise at least one strain of S. thermophilus, and / or at least one strain of L. bulgaricus. The concentrated ferments according to the invention may be in the form of frozen concentrates, for example in the form of frozen granules, and / or in the form of lyophilized concentrates. The frozen concentrates according to the invention comprise at least one strain of S. thermophilus (living or viable) with a concentration of at least 3.1010 cfu / g, and / or at least one strain of L. bulgaricus (living or viable) with a concentration of of at least 1,109 cfu / g. The lyophilized concentrates according to the invention comprise at least one strain of S. thermophilus (living or viable) of at least 1,1011 cfu / g, and / or at least one strain of L. bulgaricus (living or viable) of at least 4,109 cfu / g. The concentrated ferments according to the invention are obtained by mass inoculation of a substrate which is a culture medium (intended for cell propagation). An example of the embodiment of frozen concentrates (in the form of granules) is described in example 2 below. This culture medium generally comprises the milk and / or the components of the milk, but generally it will also contain one or more agents or substances intended to promote and / or stimulate the growth of the inoculated strains or strains. Thus, in a culture medium intended for the production of concentrated ferments according to the invention, there will be found yeast extract and / or lysate yeasts, and / or manganese sulphate and / or magnesium sulphate, and / or peptones. A culture medium intended for the manufacture of concentrated ferments according to the invention may comprise one or more surfactants and / or emulsifiers and / or solubilizing and / or detergent agents, such as polyoxyethylene-sorbitan monooletate 20 (so-called under the name of polysorbate 80. or Tween® 80).

A culture medium intended for the manufacture of concentrated ferments according to the invention may comprise compounds which are not of dairy origin, such as for example meat extracts.

Preferably, the at least one strain of S. thermophilus contained in a concentrated ferment of the invention is a strain of S. thermophilus of the fragile type, which do not produce exopolysaccharides (EPS), or which will not produce more than lower contents than a milk-based medium (milk, or medium for fermented milk model, see example 6), after cultivation of this strain at a temperature of 40 ° C up to a pH of 4.7, has a Casson viscosity at 4 ° C which is less than or equal to 500 mPa.s, preferably less than or equal to 400 mPa.s. A milk-based medium suitable for such viscosity measurement may simply be milk, or a model fermented milk medium, such as, for example, a medium composed of 120 grams of skimmed milk powder, 1 gram of N3 peptide ( Vitalarmor 950. Armor proteines), and water to form 1 L. Example 6 below presents a detailed example of the protocol. Classical inoculation doses of S. thermophilus can be used (eg, inoculation at 1% Wv)), such as those presented in Example 6. Advantageously, the at least one strain of S. thermophilus is the S. thermophilus strain. available before the CN C. M. under deposit number I-2130. Any strain of L. bulgaricus that is considered appropriate by the artisan may be used. For example, the strain available before the CNCM under deposit number 1-1519. The inoculated milk substrate, which can be obtained as an intermediate product during the production of the yoghurt or fermented milk process according to the invention, and / or during the production of the powder production process according to the invention. invention, is also the subject of the present patent application. In the description, the term "milk substrate" in the present invention is understood to mean milk in the sense used in the dairy industry, this means milk of animal origin in all its forms and in all its variants of compositions. A dairy substrate according to the invention is essentially composed of milk, to be able to produce by lactic fermentation a product that responds to the appeal of fermented milk or yogurt, intended for human consumption. The term "milk substrate" does not include the meaning of culture medium.

The yogurt or fermented milk, which can be obtained as a final product of the process for the production of yoghurt or fermented milk according to the invention, and / or as an intermediate product of the powder process according to the invention, is also the subject of the present application for patent. This fermented milk or yogurt can be produced by lactic fermentation of the inoculated substrate object of the present invention. More particularly, the present patent application refers to a dairy substrate inoculated by at least one strain of S. thermophilus with a concentration of at least 5,108 cfu. / g, and for at least one strain of L. bulgaricus with a concentration of at least 1,106 cfu / g. Naturally, all the contents of S. thermophilus and / or L. bulgaricus described in the present invention in the context of the description of the method according to the invention are applied to the intermediate product, inoculated milk substrate, while what produced; and all combinations of contents are included in the field of the present invention. Preferably, the dairy substrate comprises the at least one strain of S. thermophilus with a concentration of at least 1109 cfu / g. Preferably, the at least one strain of S. thermophilus contained in an inoculated milk substrate of the invention is a strain of S. thermophilus of the brittle type, which does not produce exopolysaccharides (EPS), or which does not produce contents lower than a medium Based on milk (milk, or fermented milk medium model; see example 6), after cultivation of this strain at a temperature of 40 ° C up to a pH of 4.7, it has a Casson viscosity at 4 ° C which is less than or equal to 500 mPa.s, preferably less than or equal to at 400 mPa.s. A milk-based medium suitable for such viscosity measurement may simply be milk, or a model fermented milk medium, such as, for example, a medium composed of 120 grams of skimmed milk powder, 1 gram of N3 peptide ( Vitalarmor 950. Armor proteines), and water to form 1 L. Example 6 below presents a detailed example of the protocol. The classical inoculation doses of S. thermophilus that can be used (for example, inoculation at 1% v / v)), such as those presented in example 6. Advantageously, the at least one strain of S. thermophilus is the strain of S. thermophilus available before the CNCM under the deposit number I-2130.

Any strain of L. bulgaricus that the person skilled in the art considers appropriate can be used, for example, the strain available before the CNCM under the deposit number 1-1519. According to a particular embodiment of the invention, the inoculated milk substrate of the invention is an inoculated milk substrate having a high MS content as described below (see also example 8), this means an inoculated milk substrate that it has an MS content in the order of 25 to 60% as described below. Advantageously, a dairy substrate of the invention inoculated to a composition such as after lactic fermentation by at least one strain of S. thermophilus and at least one strain of L. bulgaricus, the inoculated milk substrate leads to a dairy product that responds to the appeal of yogurt or fermented milk. Another product that can be obtained during the use of a process according to the invention is a fermented milk or yogurt that are obtained by lactic fermentation of the inoculated milk substrate. It presents in general the same characteristics as the substrate inoculated in terms of contents and natures in S. thermophilus and L. bulgaricus. Naturally, the fermented milk or yogurt that can be obtained during the performance of the process according to the invention has contents in L. bulgaricus and S. thermophilus that are slightly stronger than those of the inoculated milk substrate from which it comes; and, after the Casein coagulation that occurs during symbiotic lactic fermentation will pass to the gel state, as is the case for classic yogurts. The exceptional concentration of lactic acid bacteria observed at the end of the fermentation had not been obtained with the classical inoculation rates used for prior art yogurts. More particularly, a fermented milk or yogurt which can be obtained as an intermediate product during the use of a process for the production of powder according to the invention (end product of the process for the production of yoghurt or fermented milk according to the invention) comprises at least one strain of S. thermophillus with a concentration of at least 5108 cfu / g, and at least one strain of L. bulgaricus with a concentration of at least 1107 cfu / g. Naturally, all the contents and combinations of contents in S. thermophilus and / or L. bulgaricus described in the present invention in the context of the description of the method according to the invention are applied to the intermediate product, fermented milk or yogurt, produced. Preferably, the fermented milk or yogurt comprises the at least one strain of S. thermophilus with a concentration of at least 1109 cfu / g. Preferably, the at least one strain of S. thermophilus contained in a fermented milk or yogurt which can be obtained as intermediates of the process for the production of powder according to the invention is a strain of S. thermophilus of the fragile type, which do not produce exopolysaccharides (EPS), or with low contents of the milk-based medium (milk, or medium for fermented milk model, see example 6), after cultivation of this strain at a temperature of 40 ° C up to a pH of 4.7, has a Casson viscosity at 4 ° C which is less than or equal to 500 mPa.s, preferably less than or equal to 400 mPa.s. A milk-based medium suitable for such viscosity measurement can be simply milk, or a model fermented milk medium, such as, for example, a medium composed of 120 grams of skimmed milk powder, 1 gram of peptide N3 (Vítalarmor 950. Armor proteines), and water to form 1L. Example 6 below presents a detailed example of the protocol. Classical doses of inoculation of S. thermophilus can be used (for example, inoculation at 1% v / v)), such as those presented in example 6. Advantageously, the at least one strain of S. thermophilus is the strain of S. thermophilus available before the CNCM under the deposit number 1-2130. Any strain of L. bulgaricus that the person skilled in the art considers appropriate can be used, for example, the strain available before the CNCM under deposit number 1-1519. Advantageously, an inoculated milk substrate, or a fermented milk or yogurt according to the invention, comprises a single strain of S. thermophilus, which is preferably of the fragile type, and a single strain of L. bulgaricus. According to a particular embodiment of the invention, the yogurt or fermented milk is a yogurt or a fermented milk that has a high DM content as described below (see also example 8), this means a yogurt or a fermented milk that has an MS content in the order of 25 to 60%, as described below. Thanks to the mass inoculation proposed by the invention, the yoghurts or fermented milks of the invention have a L. bulgaricus / S. thermophilus ratio which is more favorable to L. bulgaricus than that which is observed using the lower doses of inoculation such as they are made in prior art. A yogurt or fermented milk of the invention differs from a classical yogurt at least by the value of the proportion L. bulgaricus / S. thermophillus. According to another particular embodiment, a yogurt or fermented milk of the invention contains the at least one strain of L. bulgaricus in a proportion of 1 ufe per 40 to 60 ufe of the at least one strain of S. thermophilus, preferably in a ratio of 1 ufe per 45 to 55 ufe of the S. thermophilus strain, more preferably in a ratio of 1 ufe per 47 to 53 ufe of the S. thermophilus strain, more preferably in a ratio of 1 ufe per 48 to 52 ufe of the S. thermophilus strain, most preferably in a ratio of 1 ufe per 48 to 51 ufe of the S. thermophilus strain. This is particularly the case when starting from inoculation doses of L. bulgaricus (LB) and S. thermophilus (ST) which is they are in a ratio of more than 1 LB to 50 ST, advantageously more than 1 LB per 100 ST, preferably of more 1 LB to 500 ST, more preferably 1 LB to 100-300 ST, most preferably 1 LB to about 200 ST . By comparison, starting from the same proportion of ST / LB inoculation, a conventional yogurt of prior art (which is obtained at inoculation doses lower than those previously known by the invention) has a proportion of 1 ufe of L. bulgaricus per 100 ufe of S. thermophilus, approximately. As illustrated in Example 10 a yogurt to the fermented milk of the invention has certain metabolic characteristics, in particular a content of folates, which are superior to those of a classic yogurt. According to a particular embodiment of the invention, the yoghurt or fermented milk has both a high DM content and an LB / ST ratio, as described below. A final product obtained according to the invention is fermented milk powder or yogurt. Preferably, the at least one strain of S. thermophilus is contained in the powder according to the invention in living or viable form has a content of at least 5108 cfu / g, preferably at least 1109 cfu / g, more preferably at least 2109 cfu / g, more preferably at least 3,109 cfu / g. Preferably, the at least one strain of S. thermophilus is contained in the powder according to the invention in living form or viable has a content between 1,109 cfu / g and 1,1010 cfu / g (limits included). Preferably, the at least one strain of L. bulgaricus is contained in the powder according to the invention in living or viable form having a content of at least 1,104 cfu / g, preferably at least 2,104 cfu / g, preferably at least 3,104 cfu / g. g, more preferably at least 4,104 cfu / g, more preferably at least 8,104 cfu / g, more preferably at least 1,105 cfu / g, still more preferably at least 3,105 cfu / g. Preferably, the at least one strain of L. bulgaricus is contained in the powder according to the invention in living or viable form having a content between 1,104 and 1,105 cfu / g. All combinations of S. thermophilus content and content of L. bulgaricus are included in the content of the present patent application. More particularly, a milk powder according to the invention advantageously comprises at least one strain of S. thermophilus in living or viable form with a concentration of at least 5108 cfu / g., preferably at least 1109 cfu / g, and at least one strain of L. bulgaricus in living or viable form with a concentration of at least 1104 cfu / g. This strong concentration in S. thermophilus and L. bulgaricus is obtained without it being necessary to enrich the yogurt or the fermented milk to be pulverized. In fact, the process of the present invention proposes to produce a yogurt or fermented milk which is already highly concentrated in S. thermophilus and in L. bulgaricus. The powder according to the invention has the advantage of responding to the appeal of yogurt or fermented milk: - it contains much more than the minimum legal content in living or viable lactic bacteria (this minimum legal content is 1.1O7 cfu / g), and - it is the result of a symbiosis between S. thermophilus and L. bulgaricus (see example 3). In addition to the advantage of constituting in itself a particularly rich source of L. thermophilus and L. bulgaricus alive, the powder according to the invention has the advantage of exhibiting preservative properties to which it is particularly remarkable. In the powder according to the invention, no substantial decrease in the population of S. thermophilus and L. bulgaricus is observed under living or viable form at the end of 4 months of storage at 5 ° C or at 20 ° C. A powder according to the invention does not suffer any detectable loss of S. thermophilus in living or viable form in relation to the fermented milk or yogurt from which it comes, after a preservation of 4 months, or even longer, at a temperature of 20 ° C. . Advantageously, at the end of 4 months at 20 ° C, the powders of the invention are at least 2,108 cfu / g of total population S. thermophilus and L. bulgaricus in living or viable form. More generally, this total population is at least 3.5.108 ufc / g, more frequently at least 4,108 cfu / g. This is in particular the case when the milk substrate used to produce the yogurt or fermented milk with a classical MS content, this means an MS content of 10 to 20%, for example 11-13%. In a particularly remarkable manner, according to one embodiment of the invention, the survival rates of the total population S. thermophilus and L. bulgaricus contained in a powder of the invention is at least 80% at the end of 4 months of preservation of the powder at a temperature of 20 ° C. This is in particular the case when the milk substrate used to produce the yogurt or fermented milk has a classical MS content, this means an MS content of 10 to 20%, for example 11-13%. More advantageously, at the end of 6 months at 20 ° C, the powders of the invention comprise more than 1.0107 cfu / g of total population S. thermophilus and L. bulgaricus in living or viable form, more generally at least 5.107 ufc / g. Frequently, this total population is at least 1,108 cfu / g, more frequently at least 4,108 cfu / g. This is in particular the case when the milk substrate used to produce the yogurt or fermented milk ka has a classical MS content, this means an MS content of 10 to 20%, for example 11-13%. In a particularly remarkable manner, according to one embodiment of the invention, the survival rates of the total population S. thermophilus and L. bulgaricus contained in a powder of the invention is at least 75%, more generally at least 85% , at the end of 6 months of storage of the powder at a temperature of 20 ° C. This is particularly the case when the milk substrate used to produce the yogurt or the fermented milk, whose powder it comes from is a milk substrate with a classical MS content (10-20%). In comparison, the commercial powders tested by the inventors show, under the same experimental conditions, a decrease in populations that is detectable over the course of the months. By way of example, the commercial powder survival rates are between 47% (Dr S? Welack M / A 5.4 Active) and 74% (EPI PY 48) after 1 month at 20 ° C. These unexpected properties and advantages of the powder according to the invention are illustrated in Examples 12 and 13 below. When the powder according to the invention is stored at 5 ° C or at 2 ° C for 6 months, the content of S. thermophilus and L. bulgaricus alive or viable (total content) does not fall below the minimum legal content of 1,107 cfu / g. In fait, in a powder according to the invention, the content of living or viable S. thermophilus and L. bulgaricus (total content) can not fall below 5,108 cfu / g after 6 months of storage at 20 ° C. The powder according to the invention has microbiological characteristics that respond to the appellation of yogurt or fermented milk. Preferably, the at least one strain of S. thermophilus contained in the powder according to the invention is a strain of S. thermophilus of the fragile type, that do not produce exopolysaccharides (EPS), or that only produce low contents of a medium based on milk (milk, or medium for fermented milk model, see example 6), after cultivation of this strain at a temperature from 40 ° C to a pH of 4.7, has a Casson viscosity at 4 ° C which is less than or equal to 500 mPa.s, preferably less than or equal to 400 mPa.s. A milk-based medium suitable for such viscosity measurement can be simply milk, or a model fermented milk medium, such as, for example, a medium composed of 120 grams of skimmed milk powder, 1 gram of peptide N3 (Vitalarmor 950. Armor proteines), and water to form 1 L. Example 6 below presents a detailed example of the protocol. Classical inoculation doses of S. thermophilus can be used (for example, inoculation at 1% v / v)), such as those presented in example 6. Advantageously, the at least one strain of S. thermophilus is the S strain. thermophilus available before CN CM. under the deposit number I-2130. Any strain of L. bulgaricus that the person skilled in the art considers appropriate can be used, for example, the strain available before the CNCM under the deposit number 1-1519. As indicated in the chapter of the methods according to the invention, it is possible, if required, to limit in preference to the minimum the number of strains of S. thermophilus and L. bulgaricus comprised in the powder according to the invention.

A powder according to the invention may comprise a single strain of S. thermophillus, which is preferably of the fragile type, and a single strain of L. bulgaricus. Advantageously, the fermented milk powder or yogurt according to the invention has an Aw (water activity) at room temperature (temperature between about 20 and 26 ° C, for example about 25 ° C) which is less than or equal to 0.3, preferably less than or equal to 0.25, more preferably less than 0.25, advantageously less than or equal to 0.2. Preferably, this Aw will be greater than or equal to 0.05, preferably greater than or equal to 0.09. According to a preferred embodiment of the invention, this Aw will be 0.05-0.25, preferably 0.05-0.20, more preferably 0.09-0.19 for example 0.10-0.19. The Aw of a powder according to the invention or of a food comprising a powder according to the invention, such as a filler according to the invention, can be measured with the aid of a dew point hygrometer, such as the Aqualab® hygrometer. , marketed by the company DECAGON DEVICES, Pullman, Washington, USA. The present invention also refers to any composition or product, which contains at least one powder according to the invention. The present invention relates more particularly to a food product containing at least one powder according to the invention.

The yoghurt powder produced according to the invention can be easily incorporated into an anhydrous filling formulation. While the food product, the present invention relates more particularly to a food filler containing at least one powder according to the invention. The inventors have observed that when the powder according to the invention is dispersed and / or incorporated into a fatty and essentially anhydrous food filler, the survival rates of the strains of lactic ferments present is not significantly different from that observed when the powder is preserved alone ( pure powder, before mixing). The food filler of the invention is preferably an essentially anhydrous filler. Essentially anhydrous filler means a concentrated suspension of powders and solid particles in a continuous phase composed of more less crystallized fatty materials. The term "stuffing" encompasses in particular the different types of chocolates (dark, white and milk) and frozen pasta. An advantageous example of essentially anhydrous filler is a fatty filler. A fatty and essentially anhydrous filling is constituted by hydrophilic powders dispersed in a continuous phase composed of a mixture of fatty materials more or less crystallized. The amount of water in an anhydrous filling is only that associated with the hydrophilic powders used. This content is less than approximately 2 to 3%, but not totally zero, in which fat filling and essentially anhydrous. A filler according to the invention may be contained of and / or on a food product, for example a bread, a candy. The texture of a filling depends on: 1) the physical state of the continuous phase (fatty materials melted or otherwise crystallized), 2) of the volume fraction occupied by the particles, 3) of its granulometric distribution and 4) of the presence Eventual emulsifiers, tenso-active molecules that lubricate the interactions between the solid particles. When the content of fatty materials is higher than 40% and that the granulometry of powders is vastly superior to minera, the first factor is predominant. The physical state of the continuous phase is a function of the nature of the fatty materials (and in particular of their content of saturated triglycerides) and of the temperature. Thus, it is possible to formulate a filling in the form of a fluid fluid at 40 ° C and a hard and brittle solid at 20 ° C. This change of state of the filling induced by the temperature allows to obtain a great diversity in the applications, which can be divided into 3 main categories: 1. application in "sandwich", this means in the form of a layer placed between two cereal bases in the broad sense, such as: 1.1. dry cakes, whose shape can be round like «Prince» of Lu, rectangular as the «Petit Ecolier» of Lu or even squares 1.2. cookies, on which several thin layers are placed of the filling and having a cereal base are superimposed to obtain the final product. A typical formulation for this type of application is the following: Table 1: The vegetable fatty materials are a mixture of palm, hydrogenated copra and hydrogenated palmetto in proportions that vary between 0 and 100%. A typical embodiment procedure is as follows: The filling is prepared by dispersing the powders in a Hobbart-type mixer of partially crystallized fatty materials at a temperature of about 30 ° C. A mixing time of 5 minutes at high speed is sufficient to obtain a homogeneous mixture of relatively fluid consistency. This filling is then transported with the help of hardened conductors towards a distributor type nozzle. A given volume of the filling is deposited on the surface of a bread, a second bread is then placed on the surface of the filling. The sandwich then passes into a cooling tunnel where it undergoes a cooling at about 1 ° C / min up to an exit temperature in the order of 18 ° C: the sandwich is then sufficient solid and cohesive to be conditioned. 2. Application in the form of a uniform layer on the surface of a cereal-based product: 2.1. the filling can for example be deposited in the center of the cereal-based product, which can take the form of a round tartlet of the type "Miní Rollos" of Lu, of a square bread of the "Mílk Break" type of Lu, or of a sponge cake of the type «Barquette» of Lu. As in the preceding case, a central filling deposit is obtained, but mostly visible. 2.2. Alternatively, the cereal-based product can be "inverted" which means coated on its lower face by a filling layer, by a soaking process to the liquid state followed by a cooling intended to be fixed to the filling layer. 2.3. Another possible application consists of a complete covering of the cereal-based product by a filling layer. This uniform layer is obtained by passing the cereal-based product under a "stream" of liquid filler, which covers the upper part and the sides produced by a layer of filler, the coating of the lower face is carried out by means of "inversion" "as described in 2. 2. 2.4. The uniform layer of filling can also be molded: the liquid filling is deposited in a mold, then cooled in order to make a solid helmet, which can then be joined with a cereal bar. This allows to make a product with an excellent surface condition (smooth) and makes it possible to mark the surface. The fill formula given in application 1 is convenient for those applications. Another possible formula is given in table 2 below. In this second example of a filling formulation, the yoghurt powder is added directly to a commercial bread (Blanche reference G-PR3040-105 of Barry-Callebaut). Table 2: 3. application in the form of "decoration" on the surface or in the mass of the product: The filling can be deposited in the form of threads or streaks on the surface of the product. The deposit technology is more similar to case 2.3., except that the "laminar" deposition (sheetíng) or "carp tail" generated by a direct current is replaced by tubes that produce filler filaments. The different applications of the filling, and more generally pastry, candy, of the powder according to the invention in particular have in common the following points: Preferably, the powder is dispersed in an anhydrous medium, whose water content is lower (only water added by the powders). The feasibility evaluations detailed in example 13 below confirm that the survival of the ferments is comparable in a medium of this type to that observed for the initial powder. • Preferably, the filling is combined with the cereal-based product after cooking. The temperature rise to which the ferments are subjected does not exceed a temperature in the order of 35 ° C to 40 ° C, for a duration in the order of a few hours maximum. The good thermal stability of the powders of the invention has been validated after more than two weeks (at 340 h) at 35 ° C. The impact of the method of incorporating the powder into the filling on the viability of the ferments is therefore negligible. • Preferably, the filling is combined with a cereal based product of low residual moisture, such as dried cakes, cookies or flakes / cereal particles. Water exchanges between the anhydrous filling and the product based on cereals are limited, which guarantees a good survival of the ferments. • for the richness in powdered ferments, the bakery or candy product obtained at the end has a "yogurt equivalent" (in terms of lactic flora) between 1 and 10: - for example, the finished product may contain 35% filling to 10% yogurt powder, either from 3.5% yogurt powder to 3,109 ferments, representing 108 ferments / g. for a finished product of 15g, representing 1, 5 109 ferments, equivalent to the amount of ferments contained in a yogurt (= 1, 25.109 ferments). - for example, the finished product can contain 67% filling to 30% yogurt powder, or 6,108 ferments. For a 22g bar, the same calculation gives 10"yogurt equivalents", this means 10 times the amount of ferments contained in a classic yogurt. The present invention relates more particularly to a bread comprising at least one powder according to the invention, and / or at least one filling according to the invention. By bread, it is understood in the present invention the cereal-based cooking products comprising a paste obtained from a mixture comprising in variable proportions one or more cereal or legume flours, or cereal or legume fractions , of the fat as well as one or several sugars, the latter can be used in negligible or null amounts for certain varieties of products such as "saltines" or biscuits. The powder according to the invention can also be used in the manufacture of a confection. The present invention therefore includes candies comprising at least one powder according to the invention, and / or at least one filler according to the invention. In the present invention, all the contents of lactic acid bacteria that are given are the contents of these lactic bacteria in living or viable form. In the present invention, the term "comprising" is synonymous with "including" or "containing", is an open term, and does not exclude the presence of one or more element (s), ingredient (s) or step (s) of additional methods that will not be explicitly indicated, while the term "consistent" or "constituted" is a closed term, which excludes the presence of any additional element, stage, or ingredient that will not be explicitly indicated. The term "consisting essentially of" or "essentially constituted by" is a partially open term, which does not exclude the presence of one or more additional element (s), ingredient (s) or step (s), insofar as these additional element (s), ingredient (s) or step (s) do not materially affect the basic properties of the invention. Accordingly, the term "comprising" (or "comprises (includes)") includes the terms "consistent", "constituted", as well as the terms "consisting essentially" and "essentially constituted by". In the present invention, the "CNCM" or "C. N. M. M." is the National Collection of Microorganism Crops; Institui Pasteur; 25 rue de Docteur Roux; F-75724 PARIS Cedex 15; France. Examples In the following examples, "ST" means Streptococcus thermophilus, and "LB" means Lactococcus bulgaricus. Example 1: manufacture of a yoghurt powder according to the invention 1. Preparation of the dairy substrate for the manufacture of yoghurt dough or fermented milk with high cell concentration: A dairy substrate is prepared in which the fermentation will allow to produce the dough yogurt or fermented milk necessary. For example, to produce a yogurt, a milk mixture (= lactic substrate) can be prepared as follows: - incorporation of skimmed milk powder into 0% fat milk to obtain a 20% dry extract (eg, for a skim milk with 8.8% dry extract, incorporate 12.8% powder to 96.2% dry extract); - let the mixture rehydrate 30 minutes at 4 ° C under gentle agitation; - pasteurization of the mixture 95 ° C with a 10 minute retention; - cooling of the mass up to 38 ° C. 2. Performing the necessary ferment for the manufacture of the yogurt dough or fermented milk, with high bacterial concentration: To make a product that responds to the yogurt appeal, it is necessary to select at least one strain of ST, and at least one strain of LB , like lactic ferments. At least one strain of ST and at least one strain of LB having a capacity of propagation on a milk substrate are preferably selected to produce one or more inoculation cultures with high density, and more particularly of the cultures whose population in ST or, where appropriate, in LB, or a ferment in which each of the populations in ST and LB is: - equal to or greater than 3.1010 cfu / g of S. thermophílus, equal to or greater than 1.1O9 cfu / g of L. bulgaricus, for ferments in frozen form, or - equal to or greater than 1,1011 cfu / g of S. thermophilus, equal to or greater than 4,109 cfu / g of L. bulgarícus, for ferments in lyophilized form. To make the dough yogurt or fermented milk which, according to the invention, is intended to be pulverized, they are selected from strains of lactic bacteria suitable for the manufacture of yogurt or fermented milk, which, preferably, produce little or no nothing of exopolysaccharides (EPS). A complementary or alternative selection criterion may thus consist of in selecting at least one strain of ST and / or at least one strain of LB that produces little or no exopolysaccharides (EPS). This criterion of low production of EPS applies more particularly to the case of ST strains, examples of suitable ST and LB strains include for example: - for ST, the strain accessible to the CN.CM under the deposit number 1 -2130 - for LB, the strain accessible before the C.N.CM under deposit number 1-1519. If necessary, the selected strains of lactic acid bacteria are revived, by transplants on culture medium. In the context of an industrial production, the selected lactic derivative (s) are then preferably conditioned in the form of lyophilized ferment, or in the form of frozen ferment (for example, following the frozen granule production protocol described below in the example). 2). To select a strain of lactic ferment that produces little or no exopolysaccharides (EPS), an adapted methodology comprises the measurement of the viscosity of the fermented milk obtained by fermentation of a milk substrate with the help of the candidate strains, such as for example a yogurt produced with the help of the candidate strains The viscosity measurement method within the dairy industry allows to determine if the strain (s) used for the Fermentation of the milk gives a fermented milk with a filamentous texture (important viscosity), if they are of the textured type (medium viscosity), or if they give a fermented milk with a brittle texture (low viscosity). The viscosity measuring method of a fermented milk comprises the use of a cooled viscometer and equipped with a system that allows to apply a decreasing and increasing tear gradient to the fermented milk, such as the cooled Mettier RM® 260 viscometer equipped with a coaxial system of type DI N 145. This rotary system allows to observe a destructuring of the product in function of a radiant linear tear, under a difficulty at a given gradient. Briefly, this method comprises: the cultivation of the candidate lactic acid strain or strains at a temperature of 40 ° C to a pH of 4.7 on an appropriate culture medium, such as the fermented milk medium model composed of 120 grams of skim milk powder, 1 gram of N3 peptide (Vitalarmor 950. Armor proteines), and water to form 1 L, [if required, several batches of fermented milks can be produced in identical conditions to have several comparable specimens] , [Classical inoculation doses of S. thermophilus can be used (for example, inoculation at 1% v / v)), such as those presented in example 6], - if the fermented milk (s) obtained models are produced closed, these fermented milks are preferably stirred manually with the help of a spatula for one minute, - incubation at 4 ° C for 30min of the fermented medium (s), or at least one sample extracted from this or these fermented media, - the viscosity measurements are made at 4 ° C, with the help of a Mettier RM® 260 viscometer cooled and equipped with a coaxial system of the DIN 145 type. The production is subjected to an increasing tear gradient of 0 to 20 s-1 for 1 minute. This phase corresponds to the ascending ramp. Then, it is subjected to a decreasing tear gradient of 20 to 0 s -1 for 1 minute, corresponding to the descending ramp. The results are obtained in the form of a continuous flow curve, with ascending ramp and descending ramp between 0 and 20 s-1. Figure 1 presents the three main types of flow curves: - the type of curve obtained with the help of the strain S. thermophilus 001 010 corresponds to a strain that gives a fermented milk with a filamentous texture (important viscosity), - the type of curve obtained with the help of the strain S. thermophilus 001 098 corresponds to a strain that is of the textured type (medium viscosity), - the type of curve obtained with the help of the strain S thermophilus TS 10B (company DSM Food specialties Dairy ingredients; BP 1; 2600 MA Delft, The Netherlands) corresponds to a strain that gives a fermented milk to a fragile texture (low viscosity).

The obtained measurements are adjusted by application of the Casson mathematical model, to obtain the Casson viscosity. The Casson model is formulated by the following equation (equation 1): r: difficulty (Pa) t0: Maximum flow limit of the product (Pa)? : Product viscosity (Pa.s) D: Tear gradient (s-1) This modeling followed by the plotting of a linear regression line on the descending part of the curve; which allows to indicate two important parameters: - the maximum flow limit of the product t0. corresponding to the ordinate at the origin, - the viscosity of Casson? of the product, corresponding to the slope of the regression line. Figure 2 illustrates the determination of the maximum flow limit t0 and the viscosity? of a fermented milk with the help of strain 001 098, on the descending flow curve modeled by Casson. 3. Manufacture of yogurt dough with high bacterial concentration: The mass yogurt or fermented milk is made by inoculating the substrate made in 1 with the help of the strains of lactic bacteria selected in 2, and leads to fermentation lactic For example, to produce a yogurt dough: - plant the mixture prepared in 1, with 20g / L of concentrated ferments prepared in 2. according to the following composition: 95% of frozen concentrates have a ST population of at least 3.1010 cfu / g , plus 5% of LB concentrate of at least 1.1O9 cfu / g; - ferment at 38 ° C for 3h to 4h to stop the fermentation at pH = 4.8 + 0.5 / -0.3 pH units (for a yogurt), for example pH = 4.8 + 0.4 / -0.3, for example pH = 4.8 +/- 0.3 pH units, for example pH 4.8 +/- 0.2 pH units, preferably pH + 0.5 / -0.1, (for a fermented milk, pH = 4.6 +/- 0.2 , usually); - stopping the fermentation by cooling and smoothing on a platform type SR10; - mass storage at 4 ° C up to 10 hours maximum. 4. Manufacture of fermented milk powder or yogurt: The yogurt or fermented milk dough obtained at point 3 is dried under mild conditions, to: - obtain an Aw (measured at room temperature, this means at a set temperature) between about 20 and 26 ° C, for example at about 25 ° C) which is less than or equal to 0.3, preferably less than or equal to 0.25, more preferably less than 0.25, advantageously less than or equal to 0.2. Preferably, this Aw will be greater than or equal to 0.05, preferably greater than or equal to 0.09. According to a preferred embodiment of the invention, this Aw will be 0.05-0.25, preferably 0.05 - 0.20, more preferably 0.09-0.19 for example 0.10-0.19, - maintaining the maximum of living and viable ST and LB cells (This means limiting the loss in living or viable cells as much as possible). The Aw measurements ("water activity") are carried out in accordance with the practice of the person skilled in the art for food products. The Aw can for example be measured with the aid of a dew point hygrometer, such as the Aqualab® brand hygrometer, marketed by the company DECAGON DEVICES, Pullman, Washington, USA. A sample of some grams of powder (or, if appropriate, the filler comprising a powder according to the invention) is introduced into a measuring dome. The dome is then placed in a tempered measurement chamber. The humidity of the air on the powder (or, if necessary, the filling) is analyzed a few minutes, then automatically compared with the humidity on the pure water at the temperature of measurement. The proportion of the two relative humidities, called water activity (Aw), is then determined by the apparatus at the end of a few minutes necessary for the equilibrium of the enclosure. Examples of suitable mild drying processes include drying by lyophilization, bed treatment fluid, and drying by gentle atomization, for example an atomization with an exit temperature less than or equal to 100 ° C, preferably less than or equal to 80 ° C, more preferably less than or equal to 60 ° C. An example of the gentle spray drying process is described in example 3 below. The drying process used should not add to the powder of the products not usable in the human diet, and / or not usable for a yogurt appeal. The list of such unwanted products may vary according to the legislation of the countries in question for a powder intended for consumption in France or in Spain under the name of yogurt, the procedure should not add maltodextrins to the powder produced. A powder according to the invention is obtained, which has a higher content of living or viable lactic bacteria, and more particularly in the case of the described yoghurt dough, a higher content of live or viable ST and LB, and which is not contaminated by unwanted germs in human food. The powder produced according to the invention from a yogurt dough then responds to the yoghurt appeal. The powder thus obtained has the exceptional ability to be stored for several months at room temperature without significant losses in live or viable lactic bacteria, or at least without significant losses in living and viable ST and LB.

More particularly, the powder according to the invention has the exceptional ability to be stored for several months at room temperature (approximately 20 ° C), without its LB and / or ST content being viable or viable not falling below the minimum limit in ST. + LB required for the yogurt appeal, without descending to a living or viable ST + LT population that is less than 10,107 cfu / g. At 35 ° C, a slow and progressive decrease of the lactic flora is observed over time: at the end of 2 weeks at this temperature, the survival rates are between 25% and 60% for S. thermophilus, this means that it is obtained at the end of storage between 1, 5,108 cfu / g and 1, 5,109 cfu / g, which remain high. Survival rates are lower for L. bulgaricus, in the order of 2 to 5%, with contents between 2,102 cfu / g and 2,103 cfu / g. It is also observed that the mortality rate at 35 ° C of the total flour of the powders of the invention is generally equivalent to that of prior art powders at 5 ° C or 20 ° C, preservation conditions considered as ideal by the expert. The powder produced has a granulometry suitable for its final use (reconstitution of yogurt that responds to the appeal of yogurt, use as an ingredient for the manufacture of a food filler, or more generally as an ingredient for the manufacture of a food product). Which can for example have a granulometry of 10 to 500 microns, preferably between 10 and 300 microns mieras Example 2: manufacture of frozen concentrates with high density in lactic ferment (ST and / or LB to each at least 5.1010 cfu / g) 1. Preparation of the inoculum: - select at least one strain of LB and / or at least one strain of ST little or no EPS producers, for example the CNCM strain 1-2130 of ST and / or strain 1-1519 of LB, - reliving the strain or strains selected by three successive transplants on a culture medium adapted to lactic acid bacteria, such as milk plus yeast extract (milk powder of low-fat milk 90 to 140g plus extract of baking powder from 0.5 to 3g QSP 1 kg with distilled water, sterilization 121 ° C 15 minutes): - 1% inoculation, incubation at 40 ° C of one or more strains of ST, at 44 ° C for the strains of LB, - stop the transplants by cooling (4 ° C) after taking (gelling milk); - sow with the aid of the last transplant (1%), 200 mL of M17 (broth marketed by Biokar Diagnostics, reference BK 0888HA) at 40 ° C (for ST), 200 ml of MRS (broth marketed by Serlabo, reference BD- 288130 (0881-17)) at 44 ° C (for LB); track optical density on a spectrophotometry at 660 nanometers; - stopping the bacterial growth of the inoculum by cold (4 ° C) after obtaining the end of exponential phase of growth (approximately 4h to 4h30 in good conditions). 2. Preparation of the fermenter (Example: Type BIOSTAT ED): Select from the normality of the regulation base - ST: 6Nt NaOH solution - LB: 2N NaOH solution, Autoclave 121 ° C 15 minutes: - intake system of base and inoculation, - base solution, - rotor and centrifuge container, - connections of the fermenter to the centrifuge, - connections to recover the sterile cream to a container, - connection of the bottle of sterile concentrate to nitrogen (nozzle + needle). Calibration of the pH probe; Sterilization of the fermenter: - fill with ultra pure water, - program a sterilization cycle in situ (121 ° C 20 minutes). 3. Preparation of the culture medium: - use of distilled water, - weighing the different compounds of the medium (see recipes below), - hydration 30 min under agitation, - sterilization in autoclave (121 ° C 15 minutes), - cooling to 4 ° C: 40 ° C (ST), 44 ° C (LB), - Transfer of the culture medium to the fermentor aseptically. Propagation medium ST Propagation medium LB - distilled water - distilled water - Ultrafiltration permeate - Ultrafiltration brine 50g / L 50g / L - Yeast extract 10g / L - Yeast extract 15g / L - Manganese sulfate 0.1 g / L - Manganese sulfate 0.1 g / L - Skim milk powder - Tween 80 10g / L starting pH 6.5 Starting pH 6.5 4. Start of propagation: - inoculation of the fermenter with the inoculum in a ratio of 100 mL for 6 liters - Start of the fermentation program that allows to regulate the temperature, regulate the pH by means of soda solutions, shake the culture medium, record the pH, temperature and volume of soda supplied. 5. Stopping the propagation: The data on the volume of soda supplied during the fermentation to regulate the pH, are treated to obtain a curve of accumulation of the volume of soda consumed as a function of time, to obtain a curve of consumption speed of soda as a function of time. The maximum point of this last curve corresponding to the moment in which the propagation is due ferment cooling 6. Cold centrifugation (example: Continuous flow rotor 8575): - extraction of the ferment per peristaltic pump, and centrifuge container feeding, - speed: 13000 rpm (ST), 10000 rpm (LB), - recovery of a part of the cream in a sterile bottle, - after centrifugation, dilute the product obtained with the cream, until it is pipettable, transfer it to a previously cooled sterile bottle (work under a laminar flow hood, keep the concentrate at temperatures below 10 ° C), 7. Freezing (work under a laminar flow hood, aseptic handling, keep the concentrate at temperatures below 10 ° C): - connection of the bottle of the diluted product to a peristaltic pump with the help of a flexible nozzle with a small section whose other end is connected to a system that allows connection with several syringe needles, - arranging an isothermal container filled with liquid nitrogen b Garlic the needles, - start the peristaltic pump and regulate the flow to obtain a regular drip of the concentrate in the liquid nitrogen, - recover and condition the granules sterilely afterwards to conserve them at -80 ° C; 7. Control the frozen concentrated granules: After making the granules quickly melt, make a counting (ST or LB: Method FIL117A: 1988). A frozen granule of S. thermophilus and / or L. bulgaricus has a population equal to or greater than 3.1010 cfu / g of ST, at 1,109 cfu / g of LB, respectively. Example 3: Example of a deep but gentle drying process In figure 3, a scheme of a soft atomization device suitable for the manufacture of a powder according to the invention is presented. A high-pressure pump 1 drives the concentrate to the atomization tubes. For a reduced step diameter, these generate the spray of the product in a cloud of fine droplets. The hot air (whose temperature will preferably be between 190 and 210 ° C) is thus led to the height of the drying chamber 2. The product and the descending air flowing in the enclosure and during this heating takes place the main transfer of the air. water from the product to air, for these air temperatures, the product temperature will preferably not exceed 80 ° C during drying. By the symmetry of the drying chamber, the air rises up the walls, dragging with it the particles of product of reduced diameter, called fines. The air thus loaded with water and fines is extracted in the upper part of the chamber (its temperature is then between 80 and 90 ° C) then it goes through a series of cyclones 3, which thanks to their geometry, ensure the air separation thin. The air thus released from The fines is extracted and expelled to the outside by a fan. A final filter guarantees a final purification of the air in order to limit the rejection of organic matter in the environment as much as possible. The fines when they are recovered and reincorporated in production 4, either at the level of the drying chamber, either at the tip of the chamber, or at the level of the external vibrating bed. This selection of the reinjection level will be oriented by the granulometry required by the producer. Down the drying chamber, the granules meet the medium temperature air (between 60 and 80 ° C) that performs two functions: the constitution of a fluid bed and continue drying. The granules, at the air temperature of the fluid bed, are extracted from the chamber and advanced in an external vibratory bed 6, which ensures the drying and cooling of the powder (up to a temperature of approximately 30 ° C) before conditioning. Generally, a sieve 7 is placed at the exit of that vibrating bed so that the small blocks formed during the drying are destroyed. The product can then be stored or conditioned. Example 4: Comparison of the fermentation kinetics obtained by mass inoculation according to the invention, with that obtained with lower doses of inoculation A milk mixture is inoculated with an ST strain (strain CNCM 1-2130) and a strain of LB (CNCM 1-1519) according to the invention, as described in point 1 of example 1.

The ST strain and the LB strain are inoculated in the form of frozen granules prepared as described in example 2 below. Each frozen granule contains at least 3.1010 cfu / g of ST, and / or at least 1.1O9 cfu / g of LB. The frozen granules of ST and LB are separated from the milk mixture, to give 2.7.109 cfu / g of ST and 1, 4.107 cfu / g of LB. These doses of inoculation are 10 to 1000 times higher than those that would classically be used during the traditional manufacture of a yogurt or fermented milk (from 0.01 g / L to 1 g / L). In parallel, the yoghurts have been produced in the same conditions, but using inoculation doses of ST and LB that are lower than those previously known by the invention (see example 4 and Figure 4), this is a dose of inoculation in ST of 1.1O7 cfu / g and an inoculation dose in LB of 5,104 cfu / g. The fermentation of this inoculated milk substrate at doses lower than those of the invention has been stirred until obtaining a yoghurt having ST and LB contents under living form of 5,108 cfu / g of ST and 5,106 cfu / g of LB. Of such contents of ST and LB correspond to the upper part of those which is that it can be obtained following the method of the prior art. These yogurts are called "reference yogurts". The pH is measured over time. Figure 4 shows the acidification kinetics obtained (bottom curve: inoculation according to the invention, which leads to a yogurt according to the invention; upper curve: inoculation at doses lower than those previously known by the invention). With the inoculation doses according to the invention, the acidification of the milk was developed in a period of time shorter than that observed with the lower doses of inoculation, but the acidification kinetics of the invention corresponds to a kinetic of manufacturing yogurts or traditional fermented milks (kinetics of the ST + LB symbiosis). In the context of the invention, the growth of lactic ferments is lower than that which can be observed in the framework of a traditional process for the manufacture of yogurt or fermented milk, but the final population in lactic ferments is much higher. The population inoculated within the framework of the invention is superior to the population that can be obtained at the end of fermentation during the production of a yogurt or fermented milk obtained from the inoculation doses in ST and LB lower than those previously known by the invention. In the context of the invention, it is observed at the beginning of the fermentation, the latency phase is considerably reduced, in relation to the fermentation obtained with lower doses of inoculation, but that the two acidification kinetics are joined at the end of the fermentation ( vertical arrows at a pH of 4.75 = moment at which fermentation is stopped by cooling). In order to ferment, the two biomasses appear to be in the stationary phase of growth, during which phase it develops the production of secondary metabolites (see example 10). Example 5: Example of preparation of the samples for the microbiological count (% of live and viable ST and LB). The powder according to the invention, or optionally the filler according to the invention, can be prepared as follows, for the use of the counting method of the lactic derivatives present. This method has been developed to optimize the technique of rehydration of yogurt powders in view of the counting of the lactic bacteria present. It is also possible to use this method for an application on fatty fillers. PRINCIPLE Rehydration of a yogurt powder in the form of granules or fine powder to improve the homogenization, the contact time with the diluent, the incubation temperature, to be in the optimum conditions to rehydrate the powder without changing the initial population of lactic ferment content of yogurt powder.

REAGENTS Diluent Tryptone salt is used to make dilutions. MATERIAL - Sterile Stomacher® bag with closure clips - Weight carrier - Precision balance 0.01 g - Sterile teaspoon - Stomacher® or homogenizer - Maria bath with thermostat and agitator - 1 ml sterile pipette_ OPERATING MODE Sample weighing Use a sterile Stomacher® bag on a weight support and a 0.01g precision balance. Weigh approximately 5 grams of powder, write down the exact amount. Add 45 grams of tryptone salt diluent, write down the exact amount. Close the Stomacher bag with the clips. Preliminary homogenization Homogenize the Stomacher bag for 10 seconds. This step allows the dust in the diluent to be suspended. Incubation Place the sacks in a stirred and warmed Maria bath 37 ° C, for exactly 30 minutes. This stage allows to lightly heat the powder that naturally dissolves in the liquid. Homogenization Re-homogenize the bag to the Stomacher® for 2 minutes. This stage allows breaking the last remaining particles in suspension and mixing the dilution well. A dilution of one tenth of the sample is then obtained. Lactic acid bacteria count of rehydrated yogurt powder.

Apply the official standard for the counting of lactic bacteria FIL 117B 1997, Yogurt: Counting of the characteristic microorganisms, colony counting technique at 37 ° C. EXPRESSION OF THE RESULT Reference is made to the standard FIL 117B: 1997 (paragraph 9) for the expression of the results. Take into account the initial dilution of the sample in the Stomacher® bag. Example 6: Example of preparation of the medium for viscosity measurement (selection of strains of the brittle type) Preparation of the fermented milks for the measurement of the viscosities: 1. Preparation of the milk milk: - 120 g of skimmed milk powder - 1 g of N3 peptide (Vitalarmor 950. Armor proteines) for 1 liter of mixture - 930 mL of the permuted water Leave the mixture for 30 minutes at room temperature, the time in which the milk powder is rehydrated. Distribute the mixture by volume of one liter in the bottles, then incubate them in the Maria bath once the water is boiling. Leave 35 minutes to reach 95 ° C in the center of the bottles. Regulate the temperature at 95 ° C and leave for 10 minutes, this time corresponds to the pasteurization of the milk.

Cool the bottles by leaving them in the cold water for 30 minutes, after placing at 4 ° C for one night. 2. Preparation of the Inoculation Transplantation of the TS10B strain (DSM Food specialties Dairy ingredients, BP 1; 2600 MA Delft, NETHERLANDS) at least 2 times in the sterilized milk plus yeast extract: - Transplant medium: 135 g of powder of skim milk + 2 g of yeast extract (BIOSPRINGER code 180) + 930 mL of the permuted water, autoclaved at 115 ° C 20 '- Inoculation at 1% - Fermentation at 44 ° C for 3 hours 3. Fermentation Incubate the 4 bottles of a liter of mixture at 43 ° C for 45 minutes. 'Inoculation: - distribute the 4 liters of mixture in 2 bottles of 2 liters + 0.02 mL of formate / L of mixture to sow the 2 L of mixture at 1% (v / v) with the ferment (see example 2 for the preparation of concentrated ferments) - homogenize well - pack: 16 containers per produced and place them in an oven at 40 ° C for fermentation Stop the fermentation at pH 4.70 (possibility of using 3 containers) by placing them at 4 ° C overnight. - the fermented milk containers are stored at 10 ° C for a week. The texture measurements are made in a J8. Example 7: A powder according to the invention has a survival rate of lactic acid bacteria after passage in an environment of the human stomach type, which is eguivalent, or even higher, at the rates presented by a yogurt. A powder according to the invention has been produced as described in example 1 (inoculation with the aid of frozen concentrates produced as described in example 2); drying procedure of example 3). This powder contains 5,109 cfu / g of ST CNCM 1-2130 and 1,106 cfu / g of LB CNCM 1-1519 in living form. This powder of the invention has also been formulated in the form of a fatty filler (composition of the filler as described in table 1 - see descriptive part -). This powder of the invention has been tested in simple form and in the form of a fatty filler. Another powder according to the invention has been produced as described in Example 8 (dairy substrate with a high MS content as described in Example 8 - MS content 30% -) inoculation with the help of frozen concentrates produced as described in Example 2, drying procedure of Example 9). This other powder of the invention has been formulated in the form of a fatty filler (composition of the filler as described in table 1 - see descriptive part -).

This other powder of the invention has been tested in the form of a fatty filler only. In parallel, the yoghurts have been produced in the same conditions as the yogurts that have been manufactured to produce the powder 1, but using inoculation doses of ST and LB that are lower than those previously known by the invention (see example 4 and FIG. 4), this is a dose of inoculation in ST of 1.1O7 cfu / g and a dose of inoculation in LB of 5,104 cfu / g. The fermentation of this inoculated milk substrate at doses lower than those of the invention and which has been stirred until obtaining a yoghurt having ST and LB contents under living form of 5,108 cfu / g of ST and 5,106 cfu / g of LB . With contents of ST and LB such that correspond to the upper limit that can be obtained following the method of prior art. These yogurts are called "reference yogurts". These powders and fillers have been subjected to a test that simulates the passage of dust in a human stomach, and the survival rates of lactic bacteria ST and LB have been measured according to the model of the TNO (Netherlands Organization for Applied Scientific Research, Utrechtseweg 48; 3704 HE Zeist; PO box 360; 3700 AJ Zeist The Netherlands) Gastro-intestinal TI M (international application WO 94/09895 and its North American counterparts, such as US 5525305). The results are illustrated in figures 9 and 10 (cumulative survival rates as a percentage of the initial dose after passage in the stomach and small intestine, for ST -figure 9- and LB -figure 10-). The results of the survival to the gastro-intestinal model show that the yoghurt powder of the invention has survival rates higher than those observed in the reference yogurt for the two species S. thermophilus and L. bulgaricus. These results show that the yoghurt powder according to the invention is a more effective matrix for providing viable yogurt bacteria in the large intestine. In addition, the survival rates are important, and the powder has notorious food qualities. It should be noted that if the powder of the invention is incorporated into a fatty medium, such as a fatty filler, the survival rates will be even better. Example 8: example of production of yoghurt or fermented milk according to the invention, which has a high content of ST and LB, and which also has a high MS content. A yogurt or a fermented milk according to the invention comprises a high content of density in ST and LB in living or viable form (contained in ST and LB in living form such as described in the application, for example ST content alive or greater than 5,108 cfu / g and live LB content greater than or equal to 1,107 cfu / g). According to a particular embodiment of the invention, the yoghurt or the fermented milk produced also have a high content of dry matter. According to the invention, such a yogurt or fermented milk can be produced from a milk substrate with a high MS content (the classical MS content of a classical dairy substrate is in the order of 10-20% approximately , usually 11-13%). The high MS content of the milk substrate can be obtained by concentrating this MS, for example by removing a part of the water contained in this lactic substrate. For this particular embodiment, the target values of high MS contents are at least 25%, for example 25-60%. A particular example of the use is the following: Raw cow's milk that has been pasteurized, homogenized (140/20 bars), cooled and transferred to a storage tank, where it has been stored until use (storage time = 24 hours) hours). The stored milk contains 39.5 g / L of fatty materials; 35.23 g / L of proteins; 129.5 g / L of dry matter (MS of 12-13%). Its density at 20 ° C is 1, 0299. By re-circulation of demineralized milk whey powder (pH of about 6.5) but whose lactose could not be eliminated (90% demineralized whey powder available in the trade, for example from LSF) has been incorporated into a volume of hot osmosis water, preferably at a temperature between 50 and 60 ° C, for example 55 ° C (0.295 kg of powder) of demineralized milk whey for 1 L of osmosis water at 55 ° C). The milk whey thus reconstituted has been subjected to a treatment at least equivalent to pasteurization (for example, temperature of 75 ° C for 15 seconds), then it has been cooled, for example at 3 ° C. The whey is then intended to be incorporated into the milk. The whey is incorporated into the milk to form a reconstituted mixture of 69% milk and 31% milk whey. The pasteurized osmosis water is then added to obtain a mixture of 42% milk, 19% reconstituted milk whey and 38% pasteurized osmosis water. The resulting solution constitutes the milk starting mixture (= lactic substrate). This "mixture" has been subjected to a heat treatment at least equivalent to pasteurization (for example, temperature of 75 ° C for 15 seconds), homogenized, cooled (for example at 3 ° C), and stored cold in a tank storage. The stored "mixture" has a content of fatty materials of 16.5 g / L, a protein content of 22.3 g / L, and an MS content of 110.81 g / L (MS of 11 -12%). Its density at 20 ° C is 1.0308. The "mixture" is then intended to be injected into the evaporators, to concentrate its MS content. Before being injected into the evaporators, the dairy "mixture" that has been stored in a storage tank, for safety, is again subjected to a heat treatment at least equivalent to pasteurization (for example, 90 ° C for 20 seconds). The The temperature applied to the milk "mix" in the evaporators is about 85 ° C at the inlet and about 55 ° C at the outlet. The DM content of the milk "mix" has been controlled at the evaporators outlet, either by direct measurement (measurement of the waste materials after 17 hours at 105 ° C), or by indirect measurement by measuring the content of the product. the density of the "mixture" that comes out of the evaporators (the MS content can be deduced from pre-established tables that give the correspondence between density and MS). When the measured MS content no longer corresponds to a required MS target value (for example, MS content of at least 36%, for example 36-48%), the milk "mix" can be recycled into the tank. storage, to be again injected into the evaporators. In the example described (milk added of reconstituted milk whey), an hour of circulation and re-circulation in the evaporators was necessary for the milk "mixture" to obtain, by evaporation, a corresponding MS content. to the necessary objective value of 36-48%. When the target value of MS has been obtained, the concentrated milk "mix" is directed towards the evaporators. Then it is intended to be inoculated by ST and LB according to the invention, this means at high contents in ST and LB, for lactic fermentation. For safety, the concentrated milk "mix", before inoculation, is again pasteurized (for example, 75 ° C for 15 seconds). The milk "mix" Concentrated and pasteurized has been cooled to an approximate temperature of the fermentation temperature. If the inoculation of ST and LB is done with the help of frozen concentrates, the pasteurized concentrated milk mixture is cooled to a temperature slightly higher than the fermentation temperature (for example, approximately 47 ° C), in order to take Consider the low temperature produced by the consequent inoculation of the frozen concentrates. In the example described, the concentrated milk mixture has been cooled to a temperature of approximately 47 ° C; has a content of fatty materials of 6.0 g / 100g, a protein content of 7.5 g / 100g, an MS content of 37.5 g / 100g (MS of 37.5%); its density at 47 ° C is 1,117. The inoculation of the milk "mixture" was carried out in a proportion of 20 g / L for ST cultures (granules of frozen concentrate of Streptococcus thermophilus CNCM I-2130) containing approximately 3.2.1011 STU per gram of concentrate frozen, prepared as described in example 2) and LB ferments (granules of frozen concentrate of Lactobacillus bulgaricus CNCM 1-1519, containing approximately 7.9.109 ufe of LB per gram of frozen concentrate, prepared as described in example 2). The inoculation and the lactic fermentation have been conducted according to the loyal and constant uses, in accordance with the norm CODEX STAN A-11 (a) -1975 (referring to Codex Stan 243-2003) and Decree of the French Republic No. 88-1203, to produce yoghurts. The lactic fermentation has been conducted at a temperature of 38 ° C, and has been stopped upon reaching a pH of 4.8 + 0.5 / - 0.3 (for a yogurt), for example pH = 4.8 + 0.4 / -0.3, for example pH = 4.8 +/- 0.3 pH units, for example pH 4.8 +/- 0.2 pH units (for a fermented milk, pH = 4.6 +/- 0.2, generally). The obtained fermented product is then a yogurt or a fermented milk: - containing high contents of ST + LB under living form, and - containing in addition to high MS contents, in particular an MS content of 36-48% (approximately 37%). The fact of using a dairy substrate with a high content of MS, as described herein, presents, in proportion to a classical dairy substrate, in particular the advantage that it can easily control, and more particularly more easily limit, the pH drop during fermentation. The milk substrate with a high DM content in fact has a stronger buffering power than the milk substrate with a classical MS content. It is thus possible to produce yoghurts and fermented milks that are not very acidic (for example pH 5.0-5.2 approximately), which corresponds to the current average taste of consumers, presenting the high contents in ST and LB.

In relation to yoghurts and fermented milks with a classic DM content, yoghurts or fermented milks with a high MS content have in particular the advantage of being more easily transformable into powder form, in particular by means of drying (atomization, for example) The transformation process is simpler to carry out and to conduct, and it is less expensive. During the transformation into powdered form, yoghurts or fermented milks with a high MS content also allow limiting the problem of the fines Example 9: others Examples of gentle and very gentle drying according to the invention According to the invention, the spraying of fermented milk or yogurt is preferably carried out under mild conditions, in order to keep the maximum of ST and LB bacteria in living or viable form. soft drying according to the invention can for example comprise a drying tower, connected to at least one cyclone One such positive generally responds to the scheme of Figure 3 and to the description given in example 3. The product to be dried is led to the top of the tower, to the atomization tubes. The hot air is also led to the upper part. of the tower The product and the hot air descends countercurrent in the tower enclosure, which leads to a transfer of the product water into the air. The air so charged with water moves along the walls of the enclosure, dragging the product particles of smaller diameters, called fines. The air thus loaded with water and fines is extracted at the top of the tower, and is directed towards the series of cyclones, which separate the air from the fines. The free air of the fines is extracted from the cyclones, and is expelled to the outside. The fines are recovered and reincorporated into the product at the level of the drying room. Below the tower, the formed granules meet with an air at a medium temperature that has the effect of constituting a fluid bed and continuing with drying. The granules are then extracted from the tower and advanced on a vibrating bed, at which level the air blows (approximate temperature to the ambient temperature). In this type of device, the air is introduced in at least two places, which are at the entrance of the tower (elevated temperature), below the tower (average temperature). If the device is associated with an external vibrating bed, the air can be introduced at the level of this third site (temperature less than or equal to the temperature of the lower part of the tower, preferably about the room temperature). The air introduced at the entrance of the tower must be at a sufficient temperature to allow a transfer of the product water into the air. This air is at an elevated temperature, generally at a temperature less than or equal to 210 ° C, for example in the order of 190-210 ° C. The air temperature below the tower it is advantageously lower than the air temperature at the entrance of the tower, to lead to a progressive cooling of the granules in formation. This type of drying tower can also be associated with an external vibrating bed, to collect the granules formed. The air can be blown at the level of that external vibrating bed; this air allows to finely finish the drying, and is at a temperature lower than or equal to that of the air in the lower part of the tower. The air blown at the level of the external vibrating bed will preferably have a temperature close to that of the environment. In this way, the granules formed by contact with the air at high temperature inside the tower, are conducted progressively down the tower and the external vibrating bed, up to a temperature close to room temperature. According to one embodiment of the invention, the air temperature at the entrance of the tower is in the order of 160-190 ° C, advantageously in the order of 170 ° C. According to one embodiment of the invention, the temperature of the air below the tower is advantageously less than or equal to 80 ° C, preferably a temperature of 60-80 ° C, more preferably in the order of 70 ° C. According to one embodiment of the invention, the temperature of the air at the level of the external vibrating bed, to which the drying tower can be associated, is a temperature of 25-40 ° C, preferably in the order of 30 ° C. A particular embodiment of the invention allows a smoother drying.

According to this particular embodiment of the invention, the air temperature at the entrance to the tower is in the order of 160-190 ° C, advantageously in the order of 170 ° C, and the air temperature below the tower is of the order of 60-80 ° C, advantageously in the order of 70 ° C. Advantageously, the air temperature at the entrance of the tower is in the order of 170 ° C, and the air temperature below the tower is in the order of 70 ° C. Preferably, according to this particular embodiment of the invention, the drying tower (more particularly, the atomization tower) is associated with an external vibrating bed, at which level the air is blown at a temperature less than or equal to the temperature of the air below the tower. More preferably, the air blown at the level of the external vibrating bed is 25-40 ° C, more preferably in the order of 30 ° C. According to the invention, the combination: - of an air temperature at the entrance of the tower in the order of 160-190 ° C, advantageously in the order of 170 ° C, - of an air temperature at the outlet of the tower in the order of 60-80 ° C, advantageously in the order of 70 ° C, and - of an external vibrating bed with blown air at about 25-40 ° C, advantageously in the order of 30 ° C, gives as resulting in a triple effect drying, which is more effective (the powder granules obtained have an MS of 97% approximately), and which is above all smoother.

These gentle and softer drying methods according to the invention can be used above all for yoghurt or fermented milk according to the invention, and more particularly for yoghurts and fermented milks with high MS contents of the invention (such as those illustrated in example 8). The granules of yoghurt powder or fermented milk, according to the invention, are then obtained. These powder granules contain high contents in ST and LB in living or viable form (contents such as those described in the present invention, for example ST content greater than or equal to 5,108 cfu / g and LB content greater than or equal to 1,104 cfu / g), and respond to the appeal of yogurt or fermented milk. These powder granules preferably have an Aw less than or equal to 0.3, preferably less than or equal to 0.2. These granules of yogurt powder have the advantage of being stored at a temperature of 20 ° C for at least four months, without a decrease in the populations of S. thermophilus and L. bulgaricus alive or viable. In fact, in these granules, the content of live or viable S. thermophilus and L. bulgaricus (total content) does not fall below 5,108 cfu / g after 6 months of storage at 20 ° C. Example 10: A powder according to the invention has characteristic metabolites that are equivalent or even superior to those of a reference yogurt obtained from inoculation doses of ST and LB lower than those previously known by the invention Two powders according to the invention have been produced as described in example 1 (inoculation with the aid of frozen concentrates produced as described in example 2, drying procedure of example 3). Powder 1 (produced as described in Example 1 - classical MS content) contains 8,109 ufe of bacteria ST (CNCM 1- 2130) and LB (CNCM 1-1518) in living form per gram of powder, and powder 2 ( produced as described in example 8 - high DM content) in contains 2.6.109 cfu / g. In parallel, yogurts produced under the same conditions as yoghurts that have been manufactured to produce powder 1 are produced, but using inoculation doses of ST and LB that are lower than those previously known by the invention (see example). 4 and Figure 4), this is a dose of inoculation in ST of 1.1O7 cfu / g and a dose of inoculation in LB of 5,104 cfu / g. The fermentation of this inoculated milk substrate at doses lower than those of the invention is contained until a yoghurt having ST and LB contents under living form of 5,108 cfu / g of ST and 5,106 cfu / g of LB is obtained. Such contents in ST and LB correspond to the upper limit that can be obtained following the method of the prior art. These yogurts are called "reference yogurts". The metabolic characteristics of the powders of the invention have been measured and compared with those of the reference yogurts: Beta-galactosidase activity: The beta-galactosidase activity has been measured by enzymatic tests (T = 37 ° C, pH = 7.3, A40inm, optical traversing = 1 cm, determination of continuous spectrophotometric rate), as described in Craven, Steers and Anfinsen (Journal of Biological Chemistry, 1965, 240: 2468-2477), or on the site of SIGMA-CHIMIE (http://www.sigmaaldrich.com/sigma/enzvme%20assav/q2513enz.pdf). The results are the following: Table 3: Proteolysis: Measurements of nitrogen contents are made: - for protids, measuring the total amount of nitrogen and multiplying this total content by 6.38 (Kjeldahl method, NF EN ISO 8968-1, May 2002 - classification index) V04-222-1), - for non-protein nitrogen (this means amino acids), by measuring NPN (Kjeldahl method, NF EN ISO 8968-4 standard, May 2002 - classification index V04-221-4), - for non-caseic nitrogen , following the protocol described in the Kjeldahl method, norm NF EN ISO 8968-2, May 2002 - classification index V04-221-2. The NF standards in particular are available before the AFNOR (French Association for Standardization; 11, rue Francis de Pressensé 93571 La Plaine Saint-Denis Cedex, France). In addition to the two powders according to the invention and the reference yogurt, the proteolysis measures were carried out in the initial milk before inoculation (milk mixture as described in example 1). The results are the following: Table 4: (1) Without urea, which is not present after fermentation. Formate: The formate content has been measured as described in the MSDA method. The MSDA is the Swiss Manual of Food Producers (2001 Edition, French translation 2002, revision 2004); is available from the Federal Office of Public Health of the Swiss Confederation (http: //www.bag.admin.ch/index.html?lang=en); and more particularly chapter 61 B "enzyme doses" of this MSDA, method 3.5 (this chapter is in particular accessible on the site http: //www.bag- anw.admin.ch/SLMB_Online_PDF/ Data% 20 SLMB MSDA Version% 20F / 44_Agen ts% 20conservateurs.pdf). The results are the following Table 5: Folates (Vitamin B9): The folate content has been measured as described in standard NF EN 14131 (February 2004 - classification index V03-137).

The NF standards in particular are available before the AFNOR (French Association for Standardization; 11, rue Francis de Pressense 93571 La Plaine Saint-Denis Cedex; France). The results are the following: Table 6: Comments: It is noted that the powders according to the invention exhibit beta-galactosidase activity and nitrogen contents comparable to those of the reference yogurt. The powders according to the invention contain formate, which show the exercise of a fermentation activity by the ST and LB inoculated according to the invention. In the powder examples according to the invention presented here, the formate contents are approximately twice less strong than those measured in the reference yogurt. Formate is produced by S. thermophilus, and is consumed by L. bulgaricus. In the powders of the invention, the ST / LB ratio is more favorable to L. bulgaricus than to the reference yogurts (approximately 2 times more than L. bulgaricus). In the powders of the invention, since there is a higher consumption of the formate, this explains the lowest level found in the yoghurt powder. But the presence of formate indicates a production of this secondary metabolite by S. thermophilus. In a particularly noteworthy manner, the inventors have found that the powders according to the invention have a folate content (vitamin B9) clearly superior to that of reference yogurts, that is a content of approximately twice as much. The metabolic characteristics of the powders according to the invention are at least equivalent to those of the reference yogurts. It is further noted that for certain secondary metabolites, such as, for example, folates (vitamin B9), the characteristics of the powders according to the invention are clearly superior to those of the reference yogurts. Example 1 1: comparison with a "fake" yogurt powder, this means to say a powder in which the bacteria have simply been introduced without producing fermentation (exogenous contribution of bacteria): A powder according to the invention has been produced as described in Example 8 (dairy substrate with a high DM content as described in example 8, inoculation with the help of frozen concentrates produced as described in example 2, drying procedure of example 9). This powder contains 2. 2.109 ufe of symbiosis yoghurt ST CNCM 1-2130 and LB CNCM 1-1519 per gram of powder. In parallel, a false yogurt powder has been produced by simply adding the ST and LB bacteria to a skimmed milk powder, without these bacteria exerting fermentation activity (simple exogenous contribution of bacteria). This fake powder has been produced in the following manner: - addition of DANISCO YO-MIX 495 LYO freeze-dried concentrated yogurt ferments to skim milk powder, so that the final concentration of ST + LB symbiosis yogurt is approximately 2.2.109 cfu / g, - homogenization by agitation. The results are the following: Table 7: It is found that the powder of the invention exhibits a beta-galactosidase activity significantly superior to that of the false powder. Comparable results can be obtained with a powder of the invention produced as described in example 1, this means from a dairy substrate having a classical value of MS content. Example 12: Comparison of powders according to the invention with commercial powders The storage capacities of the powder according to the invention have been compared to those of powders currently commercially available. Three types of powders have been compared: - the active M / A 5.4 powder marketed by Dr. Otto Süwelack (Joseph Suwelack Strasse, D-48727 Billerbeck, Germany), - the EPI PY48 and EPI 905 powders (EPI, Z.L.

Hermitage; B. P. 108; F-44153 Ancenis Cedex; France), - the powders according to the invention, which are designated: - Danone 1, Danone 2, Danone 3: powders of the invention, produced according to example 1, are added, inoculating a milk substrate with a classical MS content with the help of frozen concentrates of ST and LB (produced as described in example 2), the drying of the yogurt is conducted as described in example 3, each of the three powders Danone 1, Danone 2, Danone 3 with contents different from ST + LB, and - Danone 4: a powder of the invention, produced according to example 8, is added, inoculating a high MS content milk substrate with the help of frozen concentrates of ST and LB (produced as described in example 2), the drying of yogurt it is conducted as described in example 9. In a first series of tests, the survival of the lactic ferments of the commercial yoghurt powders and of the powders according to the invention has been evaluated under different storage conditions: powder alone or incorporation into an anhydrous filling, temperature that varies between 5 and 35 ° C and time between 3 days and more than 6 months. The proven food filler is composed of: Table 8: * Copra hydro 32 = fully hydrogenated copra with a melting point of 32 ° C The measurement of% of LB and / or live or viable ST has been made according to the official FIL method, the method of measurement of the ferments in the filling is strictly the same as for powders (5g are used in both cases and diluted in a medium, as described in example 5 onwards). The results are illustrated by tables 9 and 10 below, and by figures 5, 6 and 11. Table 9: Table 10: It is found that, contrary to commercial powders, the powders of the invention have an excellent storage stability at room temperature (T = 20 ° C for example). Figure 11 clearly illustrates this exceptional stability. At the end of 4 months of storage at a temperature of 20 ° C, the survival rates of ST + LB bacteria contained in the powders of the invention it is at least 80%, more generally at least 90%. ST bacteria have particularly high survival rates in relation to LB bacteria; Survival rates of TS are at least equal, more generally higher than survival rates ST + LB. In fact, survival rates of TS at the end of 4 months of storage at a temperature of 20 ° C are at least 90%, more generally at least 95%. At the end of 6 months of preservation of the powder at a temperature of 20 ° C, the survival rates of the population S. thermophilus and L. bulgaricus content of a powder of the invention is at least 75%, more generally at least 85% In fact, the ST survival rate at the end of 6 months of storage at a temperature of 20 ° C is at least 85%, more generally at least 90%. Example 13: Comparison of a powder according to the invention with commercial powders After the tests described in example 12, the kinetic evolutions of the enzyme populations of the three types of powder are described in example 12, which are: - powder M / A 5.4 Active sold by Dr. Otto Süwelack (Joseph-Süwelack Strasse, D-48727 Billerbeck, Germany), - EPI PY48 and EPI 905 powders (EPI, Zl of the Hermitage, BP 108; F-44153 Ancenis Cedex, France), - the powders according to the invention, which are called Danone 1, Danone 2, Danone 3 (three different contents of ST + LB). The powders according to the invention have been produced as described in example 1. The storage capacities of these powders have been compared as described in the previous example 12 (% survival), in the form of "new powder", and be in the form of anhydrous filler. The fillers have the same composition as described in Example 12 filler without water. The conservation values "new powder" and "filling" have been grouped, taking into account the dilution exerted on the filling formula. 1. Comparison of the kinetic evolution of the ferment populations: The populations of Streptococcus thermophilus and Lactobacillus bulgaricus have been measured as a function of time and temperature of conservation. The pure yoghurt powder, or if necessary, the anhydrous filling, is analyzed with the aid of the official FIL method (see example 5 below). The evolution of the populations below is represented as a function of time, and is adjusted (with the help of an Excel® solvent) with a kinetic model of order 2, as described by equation (2): C (t) = l + k-C0-t (2) where C (t) is the population in ferments at instant t (g "1), C0 is the initial population (g 1) in ferments, k the rate constant (g.día "1) and t the time (days) .This adjustment can be made both on the total population (St + Lb), or on the However, insofar as the commercial powders have a lower content with a Lactobacillus content, the analysis on the total flora has allowed an objective comparison of all the powders The following table 11 shows the results obtained. In that table 11, < C0 > and indicates the average values of the initial and constant velocity populations found respectively by means of the adjustment of different data series.

In table 11 below, the notation < > means a mean value of several measurements. to Table 11 to The initial populations have already been shown in Figure 5 and discussed in Example 12. The rate constants reflect the dispersion speed of live or viable germs, ie the mortality kinetics. The factor that dictates this kinetics is the product kxCo, which is a multiple of the time in equation (2). Figure 7 shows the evolution of this product as a function of the storage temperature and for different commercial powders and according to the invention. In figure 7 it is observed that the stability of the powders according to the invention is much higher than that of the prior art powders. In particular, the stability at 35 ° C of the powders according to the invention is (almost) comparable to that of the prior art powders between 5 ° C and 20 ° C, therefore under the preservation conditions considered as optimal by the expert. More precisely, the speed of mortality increases with temperature almost exponentially, to a critical temperature where mortality increases much more significantly. With the powders according to the invention, this critical temperature is comprised between 45 ° C and 5 ° C, and is therefore higher than those of the powders available on the market, such as those of the producer Dr Süwelack (critical temperature between 30 ° C. C and 35 ° C). The powders according to the invention thus exhibit both good stability over time at room temperature but also a good thermal stability, which make them suitable for use in food products in the Storage conditions at room temperature, or approximate of room temperature. In fact, the results obtained with only one powder are sufficiently comparable to those obtained with this same powder incorporated in the filling; This is because the two types of results, when available, are presented in a single and group of results. These results provide two comments: • A strong difference is observed in the initial populations of ferments: The concentrations measured in the commercial powders are at least 100 times lower than those measured in a powder according to the invention under the same conditions. Figure 5 illustrates the initial population differences in ferments (in this figure, DANONE 1, DANONE 2 and DANONE 3 are the powders of the present invention, while «Dr. Süwelack», «EPI PY48» are from the technical powders previous). • The speed constants are also very different: With the prior art powders, the decrease of the ferment populations is detectable on a scale of months for temperatures of 5 ° C to 20 ° C. At 35 ° C, for the powders M / A 5.4 Active of Dr Süwelack, an almost-total decrease of the ferments is observed in 2 weeks. Figure 6 illustrates at this point the evolution of the populations at 20 ° C in the 3 powders according to the invention. The bars error correspond to the uncertainty of the measure that is 0.3 log. A similar situation is observable at 5 ° C. At 30 ° C and 35 ° C, a slight decrease in the populations contained in the powder according to the invention can be measured on a weekly scale. The velocity constant values, however, are still widely lower than those observed for the prior art powders, which shows the very superior stability of the ferments in the powders generated by the invention. These results are illustrated by FIG. 7. In FIG. 7, DANONE 1, DANONE 2 and DANONE 3 are from the powders according to the invention, while "Suwelack" and "EPI" are from the prior art powders. The difference in thermal stability of the lactic flowers can be quantified considering the production of the velocity constant k and the initial population Co (table 11): In fact, in the kinetic model, time is multiplied by the product kxC0 that reflects the velocity with which the flora dies during the storage time. Figure 7 shows the evolution of the product kxC0 as a function of the storage temperature for the different powders: it is observed in particular that the speed of mortality of the ferments in Danone powder at 35 ° C is almost equivalent to that of commercial powders at 5 ° C (therefore considered by the expert as excellent preservation conditions). It is observed that at an equivalent temperature, the powders according to the invention have a better conservation than that of the prior art powders. Figures 8A and 8B present the evolution of the "normalized" population (this means the ratio between the population at a time t on the initial population) in lactic ferments during the time for the powders of the invention, and for the powders according to the invention. The time scale corresponds to given the prior art Dr. S? Welack's powders (red squares), so the adjustment according to the model of order 2 (thick continuous line). For all the other series of points, the data have been transferred on the time scale of the prior art data with the help of a multiplicative factor: for example, when the temperature increases, the lactic flora decreases more rapidly, this can be graphically compensated by using a multiplicative factor greater than 1 (for example, if the population decreases 2 times more rapidly, the factor "has" a value of 2). This multiplicative factor is correlated to the produced kxCo shown in figure 7. The data thus superimposed form the "master curves". It is thus observed that, whatever the rate of decline of the populations, all the data series follow the same kinetic evolution of order 2.

Claims (39)

1. CLAIMS 1. Procedure for the production of a fermented milk powder or yogurt, which makes it possible to obtain a powder with high density in lactic ferments Streptococcus thermophilus and Lactobacillus bulgaricus, without having to add additional lactic bacteria S. thermophilus and L. bulgaricus to the already participating in the lactic fermentation, the powder also has better storage properties of the Streptococcus thermophilus and Lactobacillus bulgaricus ferments it contains, characterized in that the process comprises: - the inoculation of a lactic substrate, which is eventually subjected to a treatment thermal at least equivalent to pasteurization, by inoculation of at least one strain of Streptococcus thermophilus with a concentration of at least 5108 cfu / g, and of at least one strain of Lactobacillus bulgaricus with a concentration of at least 1.10e cfu / g, to obtain an inoculated dairy substrate, - the fermentation l practice of the dairy substrate thus inoculated, to produce a fermented milk or a yogurt, - the pulverization of the fermented milk or yogurt thus produced until obtaining a fermented milk powder or yoghurt having an Aw (water activity) less than or equal to 0.25 , taking care that the values of temperatures applied during the spraying are sufficiently favorable for the survival of the strains of S. thermophilus and L. bulgaricus so that the powder obtained contains the at least one strain of S. thermophilus and the at least one strain of L. bulgaricus, in living or viable form, with a concentration of at least 5108 cfu / g of at least 1,104 cfu / g, respectively. Method according to claim 1, characterized in that the at least one strain of S. thermophilus is inoculated in the milk substrate with a concentration of at least 1109 cfu / g, preferably at least 2109 cfu / g, more preferably more than 2,7109 cfu / g. Method according to claim 1 or 2, characterized in that the at least one strain of L. bulgaricus is inoculated in the milk substrate with a concentration of at least 1107 cfu / g, preferably at least 1.4107 cfu / g. Process according to any one of the preceding claims, characterized in that the fermented milk powder or yogurt obtained comprises the at least one strain of S. thermophilus in living or viable form, with a concentration of at least 1,109 cfu / g. Process according to any one of the preceding claims, characterized in that the fermented milk powder or yogurt obtained comprises the at least one strain of L. bulgaricus in living or viable form, with a concentration of at least 2,104 cfu / g, preferably when minus 3,104 cfu / g, more preferably at least 4,104, more preferably at least 8,104 cfu / g, more preferably at least 1105 cfu / g, still more preferably at least 3,105 cfu / g. Method according to any one of claims 1-5, characterized in that the spraying of the fermented milk or yogurt comprises the drying and granulation of the fermented milk or yogurt by atomization. Method according to any one of claims 1-5, characterized in that the spraying of the fermented milk or yogurt comprises the lyophilization of the fermented milk or yogurt, and the granulation of the lyophilization paste. Process according to any one of claims 6-7, characterized in that it also consists of drying and granulation by atomization, or optionally, in addition to the drying by lyophilization and the granulation of the paste obtained, the spray comprises at least one drying complementary. 9. Process according to claim 8, characterized in that the at least one complementary drying is a drying on a fluid bed. Method according to claim 9, characterized in that the fluid bed is made with a gaseous flow whose temperature is lower than 80 ° C. Method according to claim 8, characterized in that the at least one complementary drying is a drying on a vibrating bed, advantageously drying on a bed vibrating at a temperature of 25 ° C to 40 ° C, preferably in the order of 30 ° C. Method according to any one of claims 8-11, characterized in that the at least one complementary drying is carried out after the granulation. Method according to any one of claims 8-12, characterized in that the at least one additional drying is carried out at a temperature of 25 ° C to 80 ° C. Method according to any one of claims 8-13, characterized in that the spraying of the fermented milk or yogurt comprises the drying and granulation of the fermented milk or yogurt by atomization, and at least one supplementary drying on a fluid bed, optionally followed at least one other complementary drying, for example on a vibrating bed. Method according to any one of the preceding claims, characterized in that the Aw is less than or equal to 0.
2. 2. Method according to any one of the preceding claims, characterized in that the Aw is 0.09 to 0.19. Process according to any one of the preceding claims, characterized in that the at least one strain of S. thermophilus is a strain of S. thermophilus of the fragile type, which does not produce exopolysaccharides (EPS), or which does not produce the low contents of a medium for fermented milk model composed of 120 grams of skim milk powder, 1 gram of peptide N3, and water to form 1 L, after cultivation of this strain at a temperature of 40 ° C to a pH of 4.7, presents a Casson viscosity at 4 ° C which is less than or equal to 500 mPa. s, preferably less than or equal to 400 mPa.s. Method according to any one of the preceding claims, characterized in that the at least one strain of S. thermophilus is the S. thermophilus strain available from C. N. CM. under the deposit number 1-2130. Process according to any one of the preceding claims, characterized in that during the inoculation of strains of S. thermophilus and L. bulgaricus, the milk substrate has a dry matter content of 25 to 60%, preferably 28 to 55% , more preferably from 38 to 45%. 20. An intermediate product that can be produced during the performance of the process according to any one of claims 1 to 19, characterized in that it is constituted of a fermented milk or yogurt containing at least one strain of S. thermophilus with a concentration of at least 5,108. ufc / g, under living or viable form, and at least one strain of L. bulgarícus with a concentration of at least 1.1O7 cfu / g, under living or viable form, and in because at least one strain of L. bulgaricus is contained in a proportion of 1 ufe for 40 to 60 ufe of the S. thermophilus strain. 21. An intermediate product according to claim 20, characterized in that the at least one strain of L. bulgaricus is contained in a proportion of 1 ufe for 45 to 55 ufe of the S. thermophilus strain, more preferably in a 1 ufe ratio of 47 to 53 ufe of the S. thermophilus strain, more preferably in a proportion of 1 ufe for 48 to 52 ufe of the strain of S. thermophilus, most preferably in a proportion of 1 ufe for 48 to 51 ufe of the S. thermophilus strain. 22. An intermediate product that can be produced during the performance of the process according to claim 19, characterized in that it is constituted by: - a milk substrate inoculated by at least one strain of S. thermophilus with a concentration of at least 5,108 cfu / g, and for at least one strain of L. bulgaricus with a concentration of at least 1,106 cfu / g, the milk substrate that is essentially composed of milk, to be able to produce by fermentation lactic one produced responds to the appeal of fermented milk or yogurt, intended for human consumption, or - a fermented milk or yogurt containing at least one strain of S. thermophilus with a concentration of at least 5108 cfu / g, under living form or viable, and at least one strain of L. bulgaricus with a concentration of at least 1.1O7 cfu / g, under living or viable form, and because the inoculated milk substrate, or, if appropriate, fermented milk or yogurt, presents a dry matter content of 25 to 60%, preferably 28 to 55%, more preferably 38 to 45%. 23. Intermediate product according to any one of the claims 20 to 22, characterized in that the at least one strain of S. thermophilus and is contained at a concentration of at least 1109 cfu / g, preferably at least 2109 cfu / g, more preferably more than 2.7.109 cfu / g. . 24. Intermediate product according to any one of claims 20 to 23, characterized in that the at least one strain of S. thermophilus is a strain of S. thermophilus called the fragile type, which does not produce exopolysaccharides (EPS), or which does not produce contents Low such a fermented model milk composed of 120 grams of skimmed milk powder, 1 gram of N3 peptide, and water to form 1 L, after cultivation of this strain at a temperature of 40 ° C to a pH of 4.7 , has a viscosity of Casson at 4 ° C which is less than or equal to 500 mPa.s, preferably less than or equal to 400 mPa.s. 25. An intermediate product according to any one of claims 20 to 24, characterized in that the at least one strain of S. thermophilus is the strain of S. thermophilus available in the C.N.C.M. under the deposit number 1-2130. 26. Intermediate product according to any one of claims 20 to 25, characterized in that the at least one strain of L. bulgaricus and is contained with a concentration of at least 1, 4.107 ucf / g. 27. Process for the production of fermented milk or yoghurt with high density in lactic ferments S. thermophilus and L. bulgaricus, comprising: the inoculation of a lactic substrate, which is eventually subjected to a heat treatment at least equivalent to pasteurization, by inoculation of at least one strain of Streptococcus thermophilus, and of at least one strain of Lactobacillus bulgaricus, to obtain a milk substrate inoculated, - the lactic fermentation of the milk substrate thus inoculated, to produce a fermented milk or a yogurt containing strains of Streptococcus thermophilus and Lactobacillus bulgaricus in living or viable form, characterized in that the at least one strain of Streptococcus thermophilus is inoculated with a concentration of at least 5,108 cfu / g, and because at least one strain of Lactobacillus bulgaricus is inoculated with a concentration of at least 1.1 O6 cfu / g. 28. Fermented milk or yogurt powder, which can be obtained by the process according to any one of claims 1 to 19, characterized in that it contains at least one strain of S. thermophilus in living or viable form with a concentration of at least 5.108 ufc / g, and at least one strain of L. bulgaricus in living or viable form with a concentration of at least 1,104 cfu / g, and because it has an Aw (water activity) less than or equal to 0.25. 29. Fermented milk powder or yogurt according to claim 28, characterized in that it contains the at least one strain of S. thermophilus in living or viable form with a concentration of at least 1,109 cfu / g, preferably at least 2,109 cfu / g. 30. Fermented milk powder or yogurt according to claim 28 or 29, characterized in that the at least one strain of S. thermophilus is a strain of S. thermophilus called the fragile type, which does not produce exopolysaccharides (EPS), or which does not produce low contents such as a fermented model milk composed of 120 grams of skimmed milk powder, 1 gram of N3 peptide, and water to form 1 L, after cultivation of this strain at a temperature of 40 ° C to a pH of 4 , 7, has a Casson viscosity at 4 ° C that is less than or equal to 500 mPa.s, preferably less than or equal to 400 mPa.s. 31. Fermented milk powder or yogurt according to any one of claims 28 to 30, characterized in that the at least one strain of S. thermophilus is the S. thermophilus strain available in the C.N.C.M. under the deposit number 1-2130. 32. Fermented milk powder or yogurt according to any one of claims 28 to 31, characterized in that it contains the at least one strain of L. bulgaricus in living or viable form with a concentration of at least 2,104 cfu / g, preferably when minus 3,104 cfu / g. 33. Powder according to any one of claims 28 to 32, characterized in that at the end of four months of preservation of the powder at 20 ° C, the total population of the at least one strain of S. thermophilus and at least one strain of L. bulgaricus that is contained in living or viable form in the powder is at the end of four months, at least 2,108 cfu / g, preferably at least 3.5108 cfu / g , more preferably at least 4,108 cfu / g. 34. Fermented milk powder or yogurt according to any one of claims 28 to 33, characterized in that it has an Aw (water activity) less than or equal to 0.2. 35. Fermented milk powder or yogurt according to any one of claims 28 to 34, characterized in that it has an Aw (water activity) of 0.09 to 0.19. 36. Food product, characterized in that it contains at least one powder according to any one of claims 28 to 35. 37. Food product according to claim 36, characterized in that it is added to a filling. 38. Food product according to claim 37, characterized in that the food filler is an essentially anhydrous filler. 39. Food product according to claim 36, characterized in that it is added to a cookie, which comprises the powder in an essentially anhydrous filling.