Classifications

• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
  • A23C9/00—Milk preparations; Milk powder or milk powder preparations
  • A23C9/12—Fermented milk preparations; Treatment using microorganisms or enzymes
  • A23C9/13—Fermented milk preparations; Treatment using microorganisms or enzymes using additives
  • A23C9/1322—Inorganic compounds; Minerals, including organic salts thereof, oligo-elements; Amino-acids, peptides, protein-hydrolysates or derivatives; Nucleic acids or derivatives; Yeast extract or autolysate; Vitamins; Antibiotics; Bacteriocins
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
  • A23C19/00—Cheese; Cheese preparations; Making thereof
  • A23C19/02—Making cheese curd
  • A23C19/05—Treating milk before coagulation; Separating whey from curd
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
  • A23C9/00—Milk preparations; Milk powder or milk powder preparations
  • A23C9/12—Fermented milk preparations; Treatment using microorganisms or enzymes
  • A23C9/123—Fermented milk preparations; Treatment using microorganisms or enzymes using only microorganisms of the genus lactobacteriaceae; Yoghurt
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23C—DAIRY PRODUCTS, e.g. MILK, BUTTER OR CHEESE; MILK OR CHEESE SUBSTITUTES; MAKING THEREOF
  • A23C9/00—Milk preparations; Milk powder or milk powder preparations
  • A23C9/12—Fermented milk preparations; Treatment using microorganisms or enzymes
  • A23C9/123—Fermented milk preparations; Treatment using microorganisms or enzymes using only microorganisms of the genus lactobacteriaceae; Yoghurt
  • A23C9/1234—Fermented milk preparations; Treatment using microorganisms or enzymes using only microorganisms of the genus lactobacteriaceae; Yoghurt characterised by using a Lactobacillus sp. other than Lactobacillus Bulgaricus, including Bificlobacterium sp.

Definitions

• the subject of the present invention is a new process for preparing a fermented milk composition, said process making it possible to obtain food compositions having a particularly high load of lactic acid bacteria, even after packaging and preservation for prolonged periods.
• lactic acid bacteria are generally known to have beneficial effects on human health, only certain categories of lactic acid bacteria are actually able to adhere to human intestinal cells, to exclude pathogenic bacteria on human intestinal cells, and / or act on the human immune system by allowing it to react more strongly to external aggressions. Lactic acid bacteria are said to be "probiotic" when they have at least one of these characteristics.
• lactic acid bacteria are truly probiotic bacteria.
• the strains Lactobacillus casei ATCC53103, Lactobacillus acidophilus CNCM 1-1225, Bifidobacterium breve CNCM 1-1226, Bifidobacterium infantis CNCM 1-1227 and Bifidobacteriun longum CNCM 1-1228 have thus been scientifically recognized as probiotic bacteria in the measurement where they are able to adhere to human intestinal cells, to exclude pathogenic bacteria on human intestinal cells, and to act on the human immune system (EP577904; EP577903; EPI 99535; Gut, 3_5_, 483-489, 1994 ; J. of Dairy Science, 7_8_, 491-197, 1995; Applied Env. Microb., £ 9_, 4121-4128, 1993).
• Probiotic lactic acid bacteria are often also extremely sensitive to oxygen, due to their adaptation to the anaerobic living conditions found in the intestinal tract. In addition, these bacteria grow poorly in milk, which poses problems in achieving a sufficient level of lactic acid bacteria in a fermented milk product.
• EPI 54614 suggests increasing the charge of the starter culture when sowing milk, and also adding growth stimulants, such as extracts, to this milk. yeast or whey protein, for example.
• the present invention aims to overcome the drawbacks of the prior art, by providing a process which promotes the survival of lactic acid bacteria.
• the present invention relates to a process for manufacturing a fermented milk composition in which milk is heat treated at a temperature and for a time such that its redox potential at 25 ° C is lowered to a value less than 450 mvolt, and the milk is inoculated with lactic acid bacteria.
• the present invention also covers all dairy compositions packaged in an impermeable or semi-permeable oxygen material, said compositions comprising at least 10 6 cfii / ml of probiotic lactic acid bacteria and a redox potential of less than 450 mvolt (cfu comes from l 'English expression "colony forming unit").
• the invention also relates to the use of a milk having a redox potential at 25 ° C. which is less than 450 mvolt, for the preparation of a dairy product comprising lactic acid bacteria.
• the invention also relates to the use of a fermented milk composition resulting from the present process in the preparation of a dairy product comprising lactic acid bacteria.
• lactic acid bacteria which are known to be sensitive to the conditions of fermentation and storage of a milk, for example sensitive to the presence of air, in fact become more resistant to these conditions, and in particular become tolerant to presence of air, as soon as the redox potential of the milk in which they live is less than about 450 mvolt. This resistance results in better bacterial development during the fermentation of milk, and better survival of bacteria during the conservation of fermented milk.
• this redox potential can be adjusted by various means, it has been found that prolonged pasteurization of milk is sufficient to achieve a required redox potential. Indeed, a prolonged heat treatment makes it possible to break certain proteins in milk and thus to release reducing groups. In addition, this treatment makes it possible to react the proteins and sugars of the milk so that it forms reducing compounds resulting from Maillard reactions.
• This pasteurization has other advantages. Firstly, prolonged treatment of milk at high temperatures promotes degassing of the milk, and therefore a low oxygen content in the milk. Second, this treatment converts part of the lactose in milk to lactulose, which is known to stimulate the growth of certain lactic acid bacteria.
• - Figure 1 shows, after fermentation, the number of cells of the strain CNCM 1-1225 (cfu / ml) having grown in different milks, said milks having undergone different heat treatments before fermentation, said fermented milks having been kept for 1 or 28 days at refrigeration temperatures, and said fermented milks having also been packaged in glass or polystyrene packaging.
• - Figure 2 shows, after fermentation, the number of cells of the strain CNCM 1-1225 (cfu / ml) having grown in different milks, said milks having a redox potential of the order of 500 mvolt or -50 mvolt before fermentation , and said fermentation being carried out under aerobic or anaerobic conditions.
• Figure 3 represents the number of cells of the strain CNCM 1-1225 (cfu / ml) having grown in different milks, as well as the redox potential at 25 ° C of these fermented milks, as a function of the storage time of these milks ferments at refrigeration temperatures.
• rennet is given to the coagulating extract coming from abomasum of young ruminants slaughtered before weaning. It will be recognized that rennet also includes veal rennet substitutes, such as animal pepsins; coagulating preparations from the plant kingdom extracted from artichoke, thistle, ficin, latex, fig, papain, for example; coagulating preparations from the microbial kingdom extracted from bacteria of the genus Bacillus and Pseudomonas, and molds belonging to the species Endothia parasitica, Mucor pusillus and Mucor miehei, for example.
• veal rennet substitutes such as animal pepsins
• milk is meant, on the one hand, a milk of animal origin, such as milk from cows, goats, sheep, buflesse, zebu, mare, donkey, camel, etc.
• This milk may be a milk in the native state, a reconstituted milk, a skimmed milk, or a milk supplemented with compounds necessary for the growth of bacteria or for the treatment of milk such as fats, yeast extract, peptone, ascorbic acid and / or a surfactant, for example.
• these milks have a pH of the order of 6.4-7, in particular pH 6.6-6.8.
• milk also applies to what is commonly called vegetable milk, that is to say an extract of plant materials treated or not, such as legumes (soy, chickpea, lentil, ect ...) or oilseeds (rapeseed, soya, sesame, cotton, ect %), extract which contains proteins in solution or in colloidal suspension, coagulable by chemical action, by acid fermentation and / or by heat.
• vegetable milks could undergo heat treatments analogous to those of animal milks. They may also have had their own treatments, such as discoloration, deodorization, and treatments for removing unwanted taste.
• the word milk also designates mixtures of animal milks and vegetable milks.
• these milks Preferably, these milks have a pH of the order of 6.4-7, in particular pH 6.6-6.8.
• the growth and survival of certain lactic acid bacteria are also influenced by the milk water activity (Aw), that is to say by the ratio between the partial vapor pressure of the water on the surface of the powder and the vapor pressure of pure water at the same temperature.
• Aw milk water activity
• the Aw can be determined by measuring the relative equilibrium humidity reached in a closed enclosure at constant temperature. For this, a sample of a few g of milk is enclosed in a sealed container placed in a room thermostatically controlled at 20 ° C. The empty space around this sample reaches equilibrium, after 30-60 min, the same Aw value as the sample.
• An electronic sensor mounted in the closure lid of the container, then measures the humidity of this empty space by means of an electrolytic resistance.
• the addition of at least one agent which promotes bacterial growth in milk makes it possible to significantly enhance the growth and survival of certain lactic acid bacteria.
• these agents there may in particular be a sugar such as glucose and sucrose, an amino acid such as cysteine and glutathione, a yeast extract in particular an extract comprising large amounts of purine and pyrimidine bases as well as their phosphate derivatives (adenosine , thymine, guanine, cytosine and uracil) and / or hydrolysates of animal or vegetable protein materials (soy), for example.
• the milk can comprise approximately 0.1-1% of yeast extract and / or approximately 0.25-1% of peptones.
• All the devices intended for pasteurizing milk can be used by a person skilled in the art. It is thus possible to heat treat milk at least 90 ° C for at least 30 min, preferably at 95-130 ° C for 30-120 min, so as to obtain a redox potential of less than 450 mvolt, in particular less than 400 mvolt, or even less than 350 mvolt if one wants to obtain maximum growth and survival of lactic acid bacteria, for example.
• the pasteurized milk is inoculated with at least one strain of lactic acid bacteria so as to obtain directly in the milk from 10 3 to 10 8 cfu / ml.
• the milk can be inoculated with a culture of fresh lactic acid bacteria, with a concentrated and frozen culture, or even with a culture dried by lyophilization or by spraying under a flow of hot air (see US389730), for example.
• the strain of lactic acid bacteria can be chosen from the Lactococcus lactis species, in particular L. lactis subsp. cremoris, L. lactis subsp. lactic biovar diacetylactis, and L. lactis; Streptococcus thermophilus; acidophilic bacteria including L. acidophilus, L. crispatus, L. amylovorous, L. gallinarum, L. gasseri, L. johnsonii; Lactobacillus fermentum; Lactobacillus casei including L. casei subsp. casei; Lactobacillus delbruckii, in particular L. delbruckii subsp lactis; L. delbruckii subsp.
• lactic acid bacteria which are sensitive to oxygen are used, in particular all bifidobacteria, Lactobacillus acidophilus, Lactobacillus johnsonii, Lactobacillus gasseri, Lactobacillus fermentum, Lactobacillus casei, Lactobacillus bulgaricus and Lactobacillus helveticus.
• Probiotic bacteria are of particular interest in the context of the present invention. These bacteria are in fact capable of adhering to human intestinal cells, of excluding pathogenic bacteria on human intestinal cells, and of acting on the human immune system by allowing it to react more strongly to external aggressions (ability to immunomodulation), for example by increasing the phagocytosis capacities of granulocytes derived from human blood (J. of Dairy Science, 7 £, 491-197, 1995: immunomodulation capacity of the strain La-1 which has been deposited at the Institut Pasteur under the number CNCM 1-1225).
• Lactobacillus acidophilus CNCM I-1225 strain described in EP577904 can be used.
• This strain was recently reclassified among Lactobacillus johnsonii, following the new taxonomy, proposed by Fujisawa et al, which is now an authority on the taxonomy of acidophilic lactobacilli (Int. J. Syst. Bact., 42, 487-791, 1992).
• Other probiotic bacteria are also available, such as those described in EPI 99535 (Gorbach et al.) Or in US5296221 (Mitsuoka et al.), For example.
• the dairy composition obtained by the process according to the invention can also be traditionally fermented until at least 10 6 cfu / ml, in particular 10? -10 9 cfu / ml, for example, are obtained.
• these milk compositions comprise probiotic lactic acid bacteria, in particular the strain L. johnsonii CNCM 1-1225, it is preferable to carry out the fermentation in the absence of oxygen, for example under an atmosphere of carbon dioxide.
• the milk composition obtained by the process according to the invention can also be transformed into unripened fresh cheeses which are commonly called in Anglo-Saxon countries “quarg” or “cottage-cheese” and in Germany “quark”, by example.
• the milk inoculated with lactic acid bacteria can be fermented, but not necessarily. Rennet is generally added to it, of the order of 0.01 to 0.15% by volume / volume, so as to pass the casein from one phase colloidal to a precipitated phase, this passage being accompanied by the formation of a whey. Then, the whey is separated by centrifugation or ultrafiltration.
• the invention also covers all dairy compositions packaged in an impermeable or semi-permeable oxygen material, said compositions comprising at least 10 6 cfu / ml of probiotic lactic acid bacteria and a redox potential of less than 450 mvolt, preferably less than 400-350 mvolt if one wants compositions in which the viability of lactic acid bacteria is stabilized at an acceptable level
• the dairy compositions according to the invention are packaged in a material which allows less than 0.01 cm 3 of air to pass per day and per cm 2 under an external pressure of 0.21 bar, for example a material impermeable to air like glass or ethyl vinyl alcohol (EVOH), or a semi-permeable material like polystyrene (PS), polypropylene (PP), polyethylene terepthalate (PET), ethyl vinyl alcohol (EVOH), high density polyethylene (HDPE), or a mixture of these materials, for example.
• a material impermeable to air like glass or ethyl vinyl alcohol (EVOH), or a semi-permeable material like polystyrene (PS), polypropylene (PP), polyethylene terepthalate (PET), ethyl vinyl alcohol (EVOH), high density polyethylene (HDPE), or a mixture of these materials, for example.
• a material impermeable to air like glass or ethyl vinyl alcohol (EVOH), or a semi
• the milk composition obtained by the present process can also be used to prepare other fermented milk products, in particular as starter for large-scale milk fermentation, for example.
• the measurement of the redox potential is carried out in accordance with the publication by Buhler H. et al. (Ingold AG, Germany). For this, a pH / mvolt meter is used combined with a redox electrode (Ingold n ° 105053288). The pH / mvolt meter is calibrated using a standard redox buffer. The milk samples at pH 6.4-7 are previously incubated in a 25 ° C bath. The redox potential is measured after 3 min of stability, and the redox potential is calculated by adding 244.4 mvolt to the displayed redox value.
• milk samples consisting of 10% of a skimmed milk powder, 1% of yeast extracts and 0.5% of glucose.
• these milks are heat treated, respectively, for 30 min at 63 ° C. in a hot water bath, for 30 min at 95 ° C. in a hot water bath, for 15 min at 121 ° C in an autoclave, or for 60 min at 121 ° C in an autoclave.
• These milks are inoculated with the probiotic strain Lactobacillus johnsonii CNCM 1-1225 which was deposited at the Institut Pasteur, 25 rue du do Sheffield Roux, Paris, June 30, 1992.
• the redox potentials are adjusted at 25 ° C of two MRS artificial media, respectively to about 500 mvolt and -50 mvolt, by adding an appropriate amount of potassium ferricynide or DTT. These two media are inoculated with an inoculum of the strain Lactobacillus johnsonii CNCM 1-1225, they are ferments at aerobic. For aerobic conditions, sterile air bubbles are introduced into the fermentation media. Finally, the number of colonies of bacteria that have grown in these milks is listed.
• Skimmed pasteurized milk is conventionally inoculated at 115 ° C. for 20 min with 5% of the starter of the strain Lactobacillus johnsonii CNCM 1-1225 and 0.5% of the starter of the strain Streptococcus thermophilus CNCM 1-1421.
• pH of fermented milks reaches pH 4.5, 0.1% w / v of vitamin C is added, the milks are packed in semi-permeable jars and kept at refrigeration temperatures for 1 , 14 or 28 days, after which the redox potential of the fermented milks is measured and the number of Lactobacillus johnsonii CNCM 1-1225 bacteria which have survived in these fermented milks is listed.
• Two milks made of 10% of a skimmed milk powder and different, yeast extract concentrations are prepared, these media are heat treated at 11 ° C for 15 min, they are inoculated with 5% of a fresh culture of the Lactobacillus johnsonii CNCM 1-1225 strain, they are incubated at 40 ° C for 1 to 28 days, and the number of lactic acid bacteria having survived these storage conditions is determined.
• fermented milks stored for 1 to 28 days are analyzed, said milks not comprising yeast extracts.

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• 1997
  • 1997-11-26 EP EP97951127A patent/EP0948262A1/de not_active Withdrawn
  • 1997-11-26 IL IL13028597A patent/IL130285A0/xx unknown
  • 1997-11-26 AU AU54789/98A patent/AU723405B2/en not_active Ceased
  • 1997-11-26 WO PCT/EP1997/005577 patent/WO1998027824A1/fr not_active Application Discontinuation
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