MXPA97005440A - Improved nutritive composition resulting from maize soaking and its obtenc procedure - Google Patents

Abstract

The present invention relates to an improved nutritional composition resulting from the soaking of corn characterized by the fact that it presents a ratio of the inorganic phosphorus and total phosphorus (Pi / Pt) concentrations between 35 and 95 percent, that the dosage of the proteins it contains made according to a test C gives a value less than or equal to 5, preferably less than or equal to 1, and still more preferably less than or equal to 0.5, and the content of total reducing substances is less than or equal to to 0.9 percent

Description

IMPROVED NUTRITIVE COMPOSITION RESULTING FROM MAIZE SOAKING AND ITS OBTAINING PROCEDURE The subject of the present invention is an improved nutritional composition resulting from the soaking of corn. It also aims at the process for obtaining a composition of these, as well as its application as a culture medium in the fermentation industries, as a food or food additive in compositions intended for humans or animals and as a useful agent for the preparation of fertilizers. intended for vegetables. The soaking of corn constitutes the first stage of the extraction of the starch in wet starch. It consists in keeping the maize placed in silos for a given time in hot water "containing a small amount of sulfur dioxide, this in order to facilitate the further separation of proteins-cellulose-starch, and to prevent otherwise side the growth of undesirable microorganisms. In the course of this operation, two essential phenomena take place simultaneously. On the one hand, the highly fermentable soluble materials contained in the corn grains are transferred in the soaking waters. On the other hand, the soaking conditions (presence of sulphites, free reducing sugars, temperature level) are favorable to the rapid development of bacteria, mainly lactic acid. The main interest of the soaking waters, commonly called "corn-steep" by the technician, is in its composition in essential compounds that are extracted from the transfer of these soluble materials. These compounds are favorable factors for the growth of microorganisms as well as the production of secondary metabolites, and make the soaking waters an ideal source of nutritious materials in the fermentation industries. Indeed, the soaking of corn contains as easily absorbed carbon sources: sugars and organic acids, as sources of nitrogen and carbon: amino acids and polypeptides and as sources of trace elements necessary for the growth of microorganisms: "regulatory" and mineral agents. In addition, it constitutes a relatively inexpensive substrate, comparatively to yeast extracts which represent the reference material in this field, and which are also used in human and animal feed. On the other hand, it is known that the use of corn soaking instead of complex nitrogen sources such as cotton or soy proteins can substantially increase the production yields of antibiotics. For use in fermentation, the soaking of corn can be previously subjected to a sterilization, in which the temperature and pH conditions are chosen as well as the duration in order to obtain the destruction of the microorganisms. Thus, the temperature is generally between 105 and 130 ° C and the pH varies between 3.0 and 8.0. However, these conditions of temperature and pH cause the precipitation of certain constituents of corn soaking, which entails numerous disadvantages. In fact, the use of this inhomogeneous maize soaking has a problem at the level of its preparation, and in particular after its concentration. In addition, its use involves the formation of an important deposit on the walls of the fermenters, a deposit that risks plugging the temperature exchangers. Finally, the recovery of fermentation products can be significantly disturbed after plugging of the membranes and filters. On the other hand, the presence of free reducing substances in the soaking of corn entails an important coloration of the product after the sterilization and concentration operations, this coloration translates into a decrease in the availability of certain nutrients it contains. In addition, these free reducing substances cause the microbiological instability of the product favoring the growth of yeasts in the course of storage.

Among the proposed solutions to dissolve the problem of the heterogeneity of corn soaking, the oldest is that of extracting the substances responsible for coagulation from the soaking of corn by chemical precipitation. Thus, the addition to corn soaking of alkaline agents (lime, soda, ...) or metal compounds is known (especially aluminum salts) in order to precipitate certain proteins, sulphite or sulfate compounds or phytic acid. However, in addition to the additional cost associated with this supplementary treatment, the major drawback is in the elimination of nutrients from the medium. In addition, such treatment requires the introduction in the soaking of corn of chemical products in quantities that may be important, which significantly modifies its composition and limits its potential uses. Likewise, ultrafiltration was used to separate the waters from soaking the corn, the molecular species, especially proteins and peptides, coagulable in the heat. This technique on the other hand is the subject of a French patent No. 2 140 672 issued to the SCHOLTENHONIG RESEARCH Company. Finally, it has been proposed more recently to treat corn soaking by enzymes. Thus, U.S. Patent Number: 4 914 029 issued to the DORR-OLIVER Company describes a treatment by a phytase-cellulase mixture. However, if such a treatment allows the precipitation of phytic acid to be avoided, it is not sufficient to completely solve the problem of the formation of a precipitate after the sterilization of corn soaking. On the other hand, a treatment by a protease is described in the Japanese patent No 04-198 080 presented by the MITSUI TOATSU CHEMICALS Company: the action of such an enzyme on a corn soak contributes to the improvement of its filterability. The soaking of corn thus treated is intended for the preparation of a liquid fertilizer. Likewise, M. ROUSHDI, Y. GHALI and A. HASSANEAN studied the action of two proteolytic enzymes (Alcalase and Neutrase manufactured by NOVO Company) on maize soaking waters in order to reduce the duration of the soaking operation and to obtain a starch that has a reduced protein content. However, it is apparent that a corn soaking treatment with a proteolytic enzyme is not sufficient to satisfactorily rule out the problems mentioned above. It has been proposed, in French Patent No. 2 254 641 presented by the CPC INTERNATIONAL COMPANY, add the lactic acid bacteria to the soaking water in the course of the soaking process with the sole purpose of reducing the duration. It was noted that a reduction in the contents of reducing sugars in the soaking waters was also obtained, evolving from 6.5 percent to 1.7-1.9 percent. However, none of the treatments described and used up to the present has satisfactorily solved the problem of the loss of a non-negligible fraction of constituents of corn soaking and therefore of their nutritional qualities, either through the formation of a precipitate or by the appearance of a marked coloration after its sterilization, or by an evolution of the aspect of the product and in particular of its color, and of its microbiological qualities during storage. Now, the applicant comes to perfect a corn soak in which the nutritional qualities are improved, which resists the thermal treatment necessary for its use as a fermentation medium, or as an additive in human or animal food and whose microbiological stability is optimal. In addition, this nutritional composition has the advantage of being able to concentrate with more than 60 percent of dry matter without facing a phenomenon of curdling in mass, as in the case of the maize soaking of the prior art. Such a concentration makes it possible to confer on the nutritional composition according to the invention a still improved microbiological stability and a viscosity perfectly adapted to the industrial conditions of use, as especially the transfer by means of pumps. It also has an economic advantage, due to a reduction in storage and transport costs, but also the costs generated by the evaporation stage. In effect, the plugging of the evaporators of the maize soaking at the superheater level represents a major problem, whose only solution today is to clean the evaporators and the pipes using soda and nitric acid. This economic advantage is still appreciable at the level of the drying stage of dry foods for animals, obtained from a composition according to the invention, for example by incorporating these in dried corn residues. To the economic advantage, in this case an ecological interest is added since the olfactory complaints associated with drying are considerably reduced. The invention thus relates in the first place to a nutritional composition characterized by the fact that it has a ratio in the concentration of inorganic phosphorus over the total phosphorus concentration comprised between 35 and 95 percent, than the dosage of the proteins it contains, performed according to a test C, gives a value less than or equal to 5, preferably less than or equal to, and even more preferably less than or equal to 0.5 and whose content in total reducing substances is less than or equal to 0. percent . The concentrations of inorganic phosphorus and total phosphorus are measured according to the known methods as described hereinafter. With regard to inorganic phosphorus, the reference method consists of measuring the absorbance, at a wavelength of 360 nm, of a complex obtained by the reaction between inorganic phosphorus and ammonium molybdate, absorbance directly proportional to the amount of inorganic phosphorus present in the sample. For the use of this method, it is possible to use for example the dosing kit sold by the company GILFOPJD DIGANOSTICS under the reference 722058. As regards the total phosphorus, its dosing is carried out according to the ISO 3946 method, which rests on the same principle as that applied to the determination of the concentration of inorganic phosphorus, described hereinabove. However, a previous stage is used, which consists of destroying the organic materials of the products to be dosed, by means of mineralization with the help of a sulfonitrile mixture and the transformation of the phosphates into orthophosphates. The next steps consist of forming the molybdic complex, then measuring the absorbance at a wavelength of 825 nm. Preferably, the concentration ratio of inorganic phosphorus over the concentration in total phosphorus (Pi / Pt) is between 60 and 95 percent, and still more preferably, between 75 and 85 percent. As far as the C test applied to the compositions according to the invention is concerned, the aim is to measure the protein concentration for 100 grams of dry matter of the supernatant of these compositions. To do so, a measurement is made - spectrophotometric of these supernatants placed in the presence of a colored reagent according to the Bradford method, known method for the dosage of proteins and described especially in Analysis Biochemistry (1976) 72, 248. In the present case, the reagent used is Coomassie Brilliant Blue G 250, manufactured by the PIERCE Company under reference 23200, and which has the peculiarity of being linked to proteins and peptides of more than 20 amino acids in acid solution, this union is accompanied by a change in color from reddish to blue. By measuring the absorbance at a wavelength of 595 nm, the absorbance corresponds to the reagent rate bound to the proteins present and consequently, proportional to the amount of proteins, after comparison with a reference standard curve obtained for different concentrations of a standard protein (Bovine Serum Albumin, Ref. 23209 of PIERCE), the protein concentration of the supernatants of the compositions is determined. To perform this measurement, the nutrient composition to be tested is previously conducted to a dry matter of 30 weight percent. This is then centrifuged at 5000 g for 15 minutes and the supernatant is recovered, and brought to dry matter of 25 weight percent. The Bradford method is then applied to this supernatant by introducing colored reagent, mixing, then reading the absorbance. The value obtained, which corresponds to the concentration of protein in grams per liter of supernatant, is then converted into a concentration in grams for 100 grams of the supernatant dry matter. The nutritional compositions object of the present invention are such that the concentration of protein in grams for 100 grams of supernatant dry matter is less than or equal to 5, and preferably less than or equal to 1. Even more preferably, the compositions according to The invention will present a protein concentration in grams for 100 grams of supernatant dry matter less than or equal to 0.5.

To measure the content of total reducing substances of a nutritional composition according to the invention, it is subjected to an acid hydrolysis by boiling it for 1 hour in the presence of hydrochloric acid in order to hydrolyze the poly and oligo saccharides present. The dosing of all the reducing substances according to the BERTRAND method is then carried out as described in the "Volumetric chemical analysis manual", H. MATHIEU, Ed. MASSON, 1946, p 398, according to the following principle: The solution containing the reducing substances is heated with an excess of cuprosodium reagent, which involves a precipitation of the cuprous oxide in an amount proportional to the concentration of reducing substances present in the solution. This precipitate, put in contact with a sulfuric ferric sulfate solution, reduces a part of ferric salt in ferrous sulfate. The ferrous sulphate is then metered in by means of a K 4 solution of known titration, which makes it possible to deduce the amount of corresponding cuprous oxide and, therefore, the amount of initial reducing substances present in the solution. The content of total reducing substances then includes both free reducing substances and reducing substances capable of being released. However, if the free reducing substances contribute, as explained above, to the physical and microbiological instability of the compositions, the presence of reducing substances capable of being released represents a certain risk of increasing this instability over time. The nutritional compositions according to the invention have a total reducing substance content of 0.9 percent by weight or less relative to the dry matter weight of the compositions, preferably less than or equal to 0.5 percent and even more preferably lower or lower. equal to 0.2 percent. The invention relates in the second place to a process for obtaining a nutritional composition resulting from the soaking of corn that has the characteristics mentioned hereinabove. This procedure consists of treating maize soaking waters in which live lactic bacteria are added, with at least one protease and at least one phytase. Surprisingly and unexpectedly, the Company Applicant has shown that a combined treatment of maize soaking waters with at least one protease and at least one phytase in the presence of added live lactic bacteria gave particularly interesting results, to which, logically, the expert does not I could wait. In fact, the results of this treatment do not correspond to the simple addition of the effects obtained by the treatment with a protease, with those obtained by the treatment with a phytase, and with those obtained after a simple addition of lactic bacteria. The Applicant Company, on the other hand, was able to demonstrate that the lactic bacteria introduced into the soaking water consumed reducing substances released following the enzymatic treatment. More precisely, these reducing substances appeared to result from secondary enzymatic activities such as amyloglucosidase, xylanase, cellulase, and other hydrolases, present in the enzymatic preparations of fungal origin of the phytase and the commercial protease. Thus, maize soaking waters in which live lactic bacteria are introduced and subjected to a combined treatment with at least one protease and at least one phytase present both excellent nutritional characteristics and optimum microbiological stability. The method according to the invention consists in introducing at least one protease and at least one phytase, simultaneously or successively, in the maize soaking water; to let them act under agitation for a duration that depends on the type of enzymes and the amounts used; in introducing the live lactic bacteria into these soaking waters previously, simultaneously or successively to the introduction of the enzymes; to follow, by taking samples, the evolution over time of the Pi / Pt ratio, the concentration of proteins and the content of total reducing substances; in inactivating these enzymes immediately; then concentrate the resulting composition by evaporation. An important step of the process according to the invention then consists in an enzymatic treatment. This treatment is carried out immediately after the soaking step of the corn, on a soaking water that has a dry matter comprised between 5 and 25 percent, and preferably between 15 and 20 percent, a pH is between 3.0 and 5.0 , and a temperature variant between 40 and 50 ° C. According to a preferred embodiment of the invention, the enzymatic treatment will be applied to the soaking waters obtained under the conditions described in French patent No. 79 22106, which already has a composition favorable to subsequent use in the fermentation industries. The order in which the enzymes are introduced is of little importance: thus, the treatment in the protease can precede or be followed immediately after the treatment with the phytase. Likewise, both types of enzymes can be used simultaneously. The amounts of enzymes used depend on the activity of the chosen enzyme and the conditions of its use (type of substrate, substrate concentration, pH, temperature, duration of treatment). These amounts are between 0.1 and 2.0 percent with respect to the dry matter of the medium in what refers to the protease and between 0.01 percent and 0.1 percent in what refers to the phytase, which corresponds to a range from 0.06 UA to 1.2 UA per 100 grams of dry matter of the medium in what refers to the protease, and from 50 to 500 UP per 100 grams of dry matter of the medium in what refers to the phytase. The Anson Unit (UA) is the protein unit, defined as the amount of enzyme that hydrolyzes the hemoglobin at the optimum temperature and pH to produce 1 micromole of Tyrosine per minute according to the colorimetric method used by the Folin reagent. Clocalteu (For a detailed description of this method, reference may be made to the article by M. L. ANSON published in 1939 in J. Gen. Physiol., 79-89). The Phytase Unit (UP) is defined as corresponding to the amount of enzyme that, at a pH of 5.5 and a temperature of 37 ° C, releases a micromole of inorganic phosphorus per minute, from a solution of sodium phytate at 0.0015 mol / liter. (For a detailed description of this method, reference may be made to international patent application No. 93/16175). The duration of the enzymatic treatment varies between 4 and 16 hours. The preferred treatment is carried out with constant agitation. The proteases which can be used in the process according to the invention are chosen in particular from acidic proteases, such as those manufactured by the BIOCON Company (ACID).

PROTEASE L B 59), by the GIST BROCADES Company (PROTEASE A), by the ROHM Company (COROLASE PS), by the GENENCOR Company (PROTEASE B99), or also by the NOVO Company (FLAVOURZIME). The protease treatment can also result from the presence itself, in the soaking water, of endogenous proteases, that is, generated by the bacteria that develop in the course of the soaking operation. With regard to phytases, we can quote by way of example FINASE manufactured by the ALKO Company, or NATUPHOS 5000 marketed by the BASF Company, or NOVO PHYTASE marketed by the NOVO Company. Another important step of the process according to the invention consists in introducing live lactic bacteria into the maize soaking waters. Preferably, the lactic acid bacteria will be introduced before or simultaneously with the enzymatic treatment.

The introduction of lactic acid bacteria is carried out either by inoculation of a culture of lactic bacteria or with the help of lactic acid bacteria obtained after the concentration, especially by centrifugation, of a medium containing them. As far as the culture of lactic bacteria is concerned, these can be obtained from lactic germs of all species of lactobacillus genus, and especially Lactobacillus delbrueckii or Lactobacillus leichmanii. These lactic germs are grown on a liquid medium adapted to their growth and this at 48 ° C for at least 8 hours under slight agitation. An inoculant of 1 to 10 percent will be introduced into the soaking waters subjected to enzymatic treatment and this, depending on its concentration. The contact time between the lactic bacteria and the soaking water submitted to the enzymatic treatment will be at least 8 hours. The samples of the reaction medium are taken at regular intervals in order to determine the concentrations of inorganic phosphorus and total phosphorus, the concentration of protein by using test C, as well as the content of total reducing substances. When the ratio Pi / Pt reaches the minimum value of 35 percent, when the concentration of protein determined by test C becomes less than or equal to 5, and when the content of total reducing substances is less than or equal to 0.9 percent, Enzymatic reactions can be stopped by the inactivation of enzymes. According to a preferred embodiment, the enzymatic reactions will stop when the ratio Pi / Pt reaches the value of 60 percent, and even more preferably 75 percent, when the concentration of protein determined according to test C is less than or equal to al, and still more preferably less than or equal to 0.5, and when the content of total reducing substances is less than or equal to 0.5 percent, and even more preferably less than or equal to 0.2 percent. To inactivate enzymes, physical (temperature) and / or chemical (pH) media are used. Preferably, the reaction medium is subjected to heating at 80-100 ° C for a time comprised between 10 and 30 minutes. In order to eliminate the microorganisms and especially the inactivated lactic bacteria after the treatment of inactivation of the enzymes and in order to obtain a clear product, the composition can be centrifuged or filtered on soil on tolle or on microfiltration membrane or on ultrafiltration. In order to improve filterability, it is possible to add xylanase-type enzymes, hemicellulases, arabinoxylanases that allow to hydrolyze insoluble substances other than proteins and phytates and lactic acid bacteria. The process object of the present invention thus allows obtaining a product whose dry matter can reach 65 percent, which has numerous advantages as described above. The compositions according to the invention, thanks to their excellent nutritional characteristics, and their improved stability present a particular interest when used as fermentation substrates. They constitute in effect a satisfactory substrate in the production under good conditions of yeasts, lactic bacteria, or other microorganisms, but also of enzymes, antibiotics, amino acids, organic acids, vitamins or biological pesticides. They are also particularly adapted to the production of metabolites obtained by genetically modified microorganisms. They are also of interest to the food industry, for their nutritional properties and for their aromatic properties, and are thus usable as food or as taste-depleting compositions intended for human or animal food. Finally, their nutritional characteristics make them completely adapted to a use in the preparation of fertilizers for vegetables. The examples given below will illustrate the invention without limiting it.

EXAMPLE 1; Production of two nutritional compositions according to the invention. Composition IA: In a 2-liter reactor, equipped with agitation and temperature regulation means, 1.5 liters of corn soaking is introduced at 200 g / 1 of dry matter. The temperature of the substrate is adjusted to 48 ° C and the stirring at 200 revolutions per minute. The pH of the product is not adjusted and then the natural pH of the corn soaking is approximately 4.2. It is then prepared according to the following protocol: a culture of lactic acid bacteria from the strain Lactobacillus delbrueckii. This strain, conserved on MRS gelled media (MAN-ROGOSA-SHARP) marketed by BIOKAR DIAGNOSTICS, previously cultivated at 48 ° C, is used in order to seed 100 milliliters of culture medium prepared by the addition of 1 percent extracts of yeast, 2 percent glucose and 0.5 percent calcium carbonate in demineralized water. This medium, introduced in an Erlenmeyer flask, is placed at 48 ° C under slight agitation for 8 hours. This culture of lactic acid bacteria is then added to the corn soak. One hour after adding the lactic bacteria, the phytase NATUPHOS 5000 (BASF) is simultaneously introduced at a rate of 0.03 percent with respect to the dry matter of the substrate as well as the protease ACID PROTEASE LB59 manufactured by the BIOCON Company at a dose of 1.5 percent with respect to the dry matter of the substrate. The total duration of the treatment is 16 hours, during which the evolution of the Pi / Pt ratio, the concentration of the proteins and the concentration of reducing substances are followed by taking samples of the reaction medium every 4 hours. The enzymatic and biological reactions are inactivated by heating at 90 ° C for 20 minutes then cooled to room temperature. The resulting product is then centrifuged at 20 ° C at a rate of 4500 g for 15 minutes. The residue, essentially constituted of inactivated lactic acid bacteria, is eliminated, the supernatant is concentrated on a laboratory evaporator to a dry matter of 50 percent. The product obtained is then cooled to room temperature under agitation. The composition obtained according to the procedure described hereinabove has a Pi / Pt ratio of 79 percent. The dosage of the proteins made according to test C gives a value of 0.25. The dosage of the reducing substances gives a value equal to 0.2 percent. Composition IB: In a 2-liter reactor equipped with agitation and temperature regulation means, 1.5 liters of maize soaking are introduced to 150 g / 1 of dry matter. The temperature of the substrate is adjusted to 48 ° C and the stirring at 200 revolutions per minute. The pH of the product does not adjust and then remains at the natural pH of the corn soak. To this substrate, are added: the phytase NATUPHOS 5000 BASF at a rate of 0.03 percent with respect to the dry matter of the substrate protease ACID PROTEASE LB59 manufactured by the BIOCON Company at a dose of 1.5 percent with respect to the dry matter of the substrate. The enzymatic reaction is then initiated. After 2 hours, the lactic acid bacteria obtained after concentration by centrifugation of 100 milliliters of soaking water produced from the last corn soaking silo before evaporation are added to the enzymatically treated corn soak. The total duration of this treatment is 16 hours during which the evolution of the Pi / Pt ratio, the concentration of proteins and the content of reducing substances are followed by taking samples of the reaction medium every 4 hours. The enzymatic and biological reactions are then inactivated by heating at 90 ° C for 20 minutes then cooled to room temperature. The resulting product is centrifuged at 20 ° C at a rate of 4500 g for 15 minutes. The residue, essentially constituted of inactivated lactic acid bacteria, is eliminated, the supernatant is concentrated on a laboratory evaporator to a dry matter of 50 percent. The composition obtained according to the procedure described above has a Pi / Pt ratio of 78 percent, the dosage of the proteins made according to the Test C gives a value of 0.2 and the dosage of the reducing substances gives a value lower than 0.25 percent.

EXAMPLE 2: Manufacture of four compositions 2A. 2B, 2C and 2D according to the prior art. The composition 2A corresponds to a control corn soak at 200 g / 1 of dry matter that has not undergone any enzymatic treatment or the addition of lactic acid bacteria. Composition 2B corresponds to a soaking of corn at 200 g / 1 of dry matter that has not undergone any enzymatic treatment but in which a culture of lactic acid bacteria obtained according to the procedure followed for the preparation of the composition IA has been added.

The composition 2C is obtained according to the described procedure to obtain the composition A before it has been added to the corn soaking, only the protease ACID PROTEASE LB 51 manufactured by BIOCON at a rate of 1.5 percent with respect to the dry matter of the substrate. The 2D composition is obtained according to the procedure described to obtain the composition IA, before only the phytase NATUPHOS 5000 (BASF) has been added to the soaking of corn, at a rate of 0.025 percent with respect to the dry matter of the substrate. The Pi / Pt ratios, the protein concentrations measured according to the C test, and the total reductive substance (SR) contents of each of the four compositions 2A, 2B, 2C and 2D are given below: 2A 2B 2C 2D Pi / Pt 20 22 20 78 Test C 1.3 1.1 0.45 1.1 SR 2 0.2 2.5 2.7 These four compositions are then concentrated to a dry matter of 50 percent.

EXAMPLE 3: Demonstration of the physical and microbiological stability of the nutritional compositions according to the invention, 3a. Decanting test The nutrient composition IA according to the invention is subjected to a decanting test, comparatively to the four compositions 2A, 2B, 2C and 2D described in Example 2. This test consists of measuring the height of the residue after decanting a composition previously sterilized. The composition IA according to the invention as well as the compositions 2A, 2B, 2C and 2D are first diluted at 25 g / liter, then the pH is adjusted to a value of 7 by the addition of an IN sodium solution. This pH value corresponds to a maximum level of protein coagulation. These compositions are then subjected to sterilization by heating at a temperature of 120 ° C for 20 minutes. They are cooled down immediately, they are homogenized then they are introduced in graduated cylinders in which they are left to decant. For each of the 5 compositions, the height of the residue is measured after 30 minutes, and after 16 hours. The values obtained, expressed in millimeters, are the following: Composition 30 min 16 IA (Invention) 12 10 2A 170 85 2B 175 90 2C 160 80 2D 50 35 Upon reading these results, the superiority of the composition according to the invention clearly appears. In effect, the residue is considerably reduced with respect to that observed after sterilization of each of the compositions according to the prior art. 3b. Coloring test The nutritive composition IA according to the invention is subjected to a coloring test, comparatively to the four compositions 2A, 2B, 2C and 2D described in example 2. This test consists of measuring the coloration of the compositions immediately after its Concentration at 50 percent dry matter, then after 1 month of storage at room temperature. This measurement of the coloration is carried out in the following manner. 10 g of compositions with 50 percent dry matter are introduced into 50 ml of distilled water. Immediately add 75 milliliters of a lead nitrate solution to 25 g / 1. After agitation after filtration, the optical densities (D) are measured at 450 nanometers and 650 nanometers. The coloring is given by the formula: DO. = E (450 nm) - D (650 nm) x 160 4 The obtained values are the following: Composition After concentration After 1 month ÍA invention 4.3 4.9 2A 2.5 7.2 2B 2.5 3.2 2C 5.2 8.4 2D 8.1 16.3 An evolution of the coloration during storage it means a physical instability of the product. The composition according to the invention seems to be perfectly stable since its coloration does not evolve practically after a month of storage, contrary to the compositions of the prior art. 3c. Microbiological stability test The nutritive composition IA according to the invention is subjected to a microbiological stability test, comparatively with the four compositions 2A, 2B, 2C and 2D described in example 2. This test consists of carrying out a numbering of yeasts after 15 minutes. days of storage at room temperature of the different compositions. These numbers are carried out on OGA medium (Oxitetracycline-Glucose-Agar) marketed by BIOKAR DIAGNOSTICS after 48 hours of incubation at 30 ° C. The results obtained, expressed in CFU (colony forming unit) per milliliter, are the following: Composition CFU / ml IA invention 100 2A 1200 2B 80 2C 1850 2D 1700 The reading of these results allows to conclude an excellent microbiological stability of the composition according to the invention, which only the known composition 2B can match on this plane.

EXAMPLE 4: Application of the compositions according to the invention to the growth of microorganisms 4a. The study described hereinafter consists of following the increase in the number of cells as a function of time in the culture medium containing a given concentration of the nutritional composition IA according to the invention compared to a culture medium containing the same concentration of compositions 2A, 2B, 2C, 2D described in Example 2. The study concerns the growth of a Bacillus subtilis strain. The culture media are prepared by adding glucose in a demineralized water at a rate of 10 grams / liter and the nutrient composition IA at a concentration of 2.6 grams / liter. (This concentration corresponds to an equivalent nitrogen of 0.086 grams / liter). Simultaneously and in the same manner, culture media containing 2.6 grams / liter of the compositions 2A, 2B, 2C, 2D described in Example 2 are prepared. These culture media are then sterilized at 120 ° C for 20 minutes. 100 milliliters of each of these media are then seeded with 0.1 percent by volume of a preculture of the strain. The incubation is carried out at 30 ° C under an agitation of 280 revolutions per minute for 24 hours. The numerations are carried out at times 0, 8 hours and 24 hours on tripticase-soy gelled medium (DIFCO). The results obtained, expressed in CFU (unit-forming colony) per milliliter, are compared in the table below.

CFU / ml Composition 0 hours 8 hours 24 hours ÍA Invención l.9xl02 7.3xl06 2.6xl09 2A l.lxlO2 2xl06 1.6xl08 2B 1.25xl02 2xl06 1.9xl08 2C 1.5xl02 3.5xl06 5xl08 2D 1.9xl02 6.2X106 lxlO9 The results obtained demonstrate the particularly interesting nutritional qualities of the composition according to the invention with respect to the compositions do not have the claimed characteristics. 4b. The study described above consists in following the evolution of yeast growth of the genus Saccharomyces cerevisiae by measuring glucose consumption and absorbance as a function of time, in a culture medium containing a given concentration of the nutrient composition IA according to the invention comparatively with a culture medium containing the same concentration of the nutritional composition 2A described in example 2. The culture media are prepared by the addition, in the demineralised water, of glucose at the rate of 50 grams / liter and of the nutritive composition IA or 2A at a concentration of 10 grams / liter. The pH of each of these media before sterilization is adjusted to 5 by the addition of soda. These are then sterilized at 120 ° C for 20 minutes in the 2 liter fermenters at a rate of 1.5 liters of medium per fermenter. Each fermenter is then seeded with 100 milliliters of a preculture of Saccharomyces cerevisiae contained in a 500 milliliter flask and obtained as follows: glucose is added in demineralized water at a rate of 10 grams / liter and yeast extracts at a rate of 2 grams / liter. After sterilization, this preculture medium is seeded with the strain Saccharomyces cerevisiae grown on gelled OGA medium. The medium is agitated on a stirrer at 200 revolutions per minute maintained at 30 ° C for 8 hours. After sowing, the fermenters kept at 30 ° C are stirred at 1 v / v / minute (volume and air per volume of medium per minute). The absorbance and glucose concentration of each of them is measured after 17 hours and 24 hours. The results obtained are compared in the table below: ÍA (Invention) 2A Absorbency Glucose Absorbency Glucose in g / 1 in g / 1 O h. 0 4 40 0. 6 40 17 h. 16 6 14 14 22 24 h. 25 5 0 20. 7 8 The absorbance was measured at 620 nm on the 1/50 dilutions. The values indicated here correspond to the absorbance read multiplied by the dilution factor. The results obtained demonstrate the excellent nutritional qualities of the composition according to the invention. It is observed in fact that the culture medium containing the nutritional composition according to the invention allows an accelerated growth of the yeast, which is translated by a decrease in the glucose concentration and an increase in the absorbency in the course of faster times than with a culture medium containing an untreated corn soak.

The set of results given in examples 3 and 4 here above demonstrate that only the compositions according to the invention have the set of qualities required, both at the level of their physical stability and at the level of their microbiological stability, which makes them compositions with excellent nutritional characteristics, perfectly adapted to the uses they need a sterilization stage.

Claims (11)

1. Nutritious composition resulting from the soaking of corn, characterized by the fact that it presents a ratio of inorganic phosphorus and total phosphorus concentrations (Pi / Pt) between 35 and 95 percent, that the dosage of proteins it contains, made according to a C test, gives a value less than or equal to 5, and that its content in total reducing substances is less than or equal to to 0.9 percent.

2. The nutritional composition according to claim 1, characterized in that its Pi / Pt ratio is comprised between 60 and 95 percent, preferably between 75 and 85 percent, than the protein dosage it contains, made according to a test C, gives a value less than or equal to 1, preferably less than or equal to 0.5, and that its content in reducing substances is less than or equal to 0.5 percent, preferably less than or equal to 0.2 percent.

3. Nutrient composition according to one or the other of claims 1 and 2, characterized in that it has a dry matter greater than or equal to 60 percent.

4. Method for obtaining a nutritional composition according to claim 1, characterized in that the corn soaking waters are subjected to an enzymatic treatment with the help of at least one protease and at least one phytase and they add and act previously, simultaneously or successively to said enzymatic treatment, of live lactic bacteria. Process according to claim 4, characterized in that it consists of introducing successively or simultaneously in the corn soaking water at least one protease and at least one phytase, in introducing and allowing to act, in the water soaking the corn, previously or simultaneously with the introduction of enzymes, lactic acid bacteria, in allowing the enzymes to act under agitation, in following, through sampling, the evolution in the course of time of the Pi / Pt ratio, of the concentration of proteins , and of the content of total reducing substances, in inactivating the enzymes, in concentrating the resulting composition by evaporation. 6. Method according to one or the other of claims 4 and 5, characterized in that the enzymatic treatment is carried out at a temperature ranging between 40 and 50 ° C, on a soaking water whose dry matter is between 5 and 5 ° C. and 25 percent and the pH between 3 and

5. The method according to any of claims 4 to 6, characterized in that the contact time between the lactic acid bacteria and the soaking water subjected to the enzymatic treatment It is at least 8 hours. 8. Use of a nutritional composition according to any one of claims 1 to 3 as a culture medium for microorganisms. 9. Use of a nutritional composition according to any of claims 1 to 3 as a food or food additive in compositions intended for human beings. 10. Use of a nutritional composition according to any of claims 1 to 3 as a food or food additive in compositions intended for animals. 11. Use of a nutritional composition according to any of claims 1 to 3 as an agent for the preparation of fertilizers intended for vegetables.