FR2760751A1 - PROCESS FOR THE PRODUCTION OF A MIXTURE OF SURFACTANT PROTEINS FROM OIL MACHINERY - Google Patents

Abstract

The invention relates to a process for the production of a mixture of surfactant proteins from oil cakes, which can be used as a technological aid or ingredient in particular in food, pharmaceutical or cosmetic preparations. According to the invention, said method comprises the following steps:. the shaping of proteins from oil cakes and the production of an ultra-fine grind of flour; . solubilization of proteins; . extraction and purification of surfactant proteins by microfiltration; . sterilization and drying of the surfactant protein filtrate; The extract obtained constitutes a mixture of surfactant proteins used mainly in food, dietetic, pharmaceutical or cosmetic preparations.

Description

 The invention relates to a process for preparing a mixture of functional proteins from oil cake. The invention also relates to the process for obtaining these surfactant proteins.

 The oil cake contains high proportions of protein matter represented by the globulin family. These proteins have functional or surfactant properties and are used as an auxiliary / manufacturing ingredient or technological aid.

 The invention also relates to the fields of application of such products considered as ingredients in the preparation of food, pharmaceutical and cosmetic products.

 By surface-active proteins is meant in particular molecules capable of adsorbing at the oil / water or air / water interfaces and therefore endowed with functional properties (emulsifying, foaming, gelling, hydration, viscosity and solubility).

The surfactant proteins from oil cake are amphiphatic molecules of low molecular weight from 10 to 26 kDa and are formed from 3 distinct domains. An amphiphatic N-terminal domain, a hydrophobic central domain and a domain
Relatively polar C-terminal.

 These defatted vegetable protein products are called flours if they contain less than 65% protein, concentrates if they contain 65 to 90% protein and isolates if they contain more than 90% protein.

 Various methods are known for preparing functional proteins. These methods include heat treatment and organic solvent extraction, as well as other chemical treatments and applied conditions which denature or significantly reduce the functional properties of proteins.

 Several methods for preparing functional proteins have been described. The teachings of the prior art indicate that to introduce or regenerate some of these functional properties in denatured material, it is necessary to apply high temperatures, higher than the boiling point of water. , (such as obtained with steam jet cooking appliances) or large shear forces (such as obtained by the application of successive pressure and cavitation, for example using a centrifugal homogenizer) on an aqueous suspension, slightly alkaline, denatured material.

 According to the process of the invention, the material comes from oil cakes obtained from oil seeds having undergone a thermal and mechanical treatment of conditioning and pressing.

 Patent LUA NO 4,113,716 describes a process for obtaining improved soy protein fractions from previously denatured soy protein by cooking a slightly alkaline aqueous suspension of denatured soy protein at temperatures included between 1100C and 1500C in a jet cooking chamber and by removing from this high temperature treated material soluble fractions having properties superior to those obtained by using defatted and non-denatured soy flakes as starting material.

 US Patent No. 4,234,620 describes a process in which aqueous dispersions of vegetable protein are subjected to large shear forces resulting from the application of successive pressure and cavitation by centrifugal homogenization at temperatures below 150 "C, at slightly alkaline pH, in order to obtain a low viscosity product with a high dry matter content, having a high protein solubility, dried after adjustment of the pH with an acid, to obtain a vegetable protein product similar to milk protein .

 British Patent No. 1,575,052 describes that the taste, color, nutritive power and certain functional properties of a protein material chosen from a protein material of single-cell origin, a vegetable protein material, dry extracts of whey and their mixtures, can be improved by heating aqueous suspensions of the proteinaceous material at temperatures between 75 and 1000C, by adjusting the pH in a range from 6.6 to 8.0 preferably from 7.2 to 7.6, by addition of a compound of adjusting the pH, preferably a calcium compound, by maintaining the temperature for a period of 1 to 120 minutes and drying the product.

 The product obtained can be used as a substitute for dry extracts of eggs and milk powder without fat, in particular in baked products, since the process attenuates the yeast aftertaste, releases buffering substances from yeast cells, saponifies lipids and reduces existing thiol groups (-SH).

 British patent No. 0 522 8000 describes a process for the manufacture of vegetable protein concentrates at their isoelectric point. The concentrate obtained with a protein content of less than 70%, more precisely between 65% and 70%, has a high functionality. adsorption of fat and water in the form of a stable emulsion. This process according to the invention is carried out without considerable shearing force on the aqueous phase of protein concentrate at alkaline pH, and a heat treatment of between 75 "C. - 95''C for I to 120 minutes, preferably between I and 60 minutes, neutralization of the protein suspension at pH between 6.8 and 7, and optionally evaporation of the neutralized suspension and spray drying coupled with spraying. The treated aqueous phase corresponds to a solid content of 12 - 25%, preferably 12 - 17%. The alkaline treatment is between 7.5 to 9.0 or 9.0, preferably 7.5 and 8.5.

 The heat treatment is carried out between 800C and 950C, approximately 85 "C for approximately 30 minutes. In the process of the invention, the alkali or base used is sodium hydroxide, similarly other alkalis can be used according to the inventive method: potassium, calcium, and ammonium The solution is neutralized by the addition of hydrochloric acid.

 The product obtained, the protein concentrate, is capable of forming a stable emulsion comprising 1 part of protein concentrate, 5-15 (5-10) parts of water, and 5-30 (preferably 5-20) parts of fat. This product results in the formation of a stable emulsion comprising 1 part of protein concentrate, at least 5 parts of water and at least 5 parts of fat.

 British patent WO 89.04209 describes emulsifying proteins in the form of an alpha helix. These proteins are amphiphatic, they have a hydrophilic and hydrophobic domain. According to the teaching of the prior art, the surface properties of proteins can be increased after partial denaturation either by mechanical treatment or by heat treatment.

The work of Kaiser et al., Sparow et al .; and Epand et al. (Peptides: Structure and
Function; Proc. Am. Peptide Symp. 9, 1985) discovered the emulsifying properties of polypeptides (proteins) in the form of alpha helices, having a hydrophilic and hydrophobic domain, present at the lipid-polar phase interface. Preferably, the hydrophobic domain is formed by hydrophobic amino acids such as: glutamic acid, lysine and serine, which contribute to the stabilization of the emulsion by hydrophobic interactions in the form of an alpha helix.

 Patent SP 0704.166 describes a process for the production of soy proteins which comprises a step of dissolving the deoiled soy flour in an aqueous phase in a ratio of 1 part of flour to (2-5) parts of water.

 Homogenization is carried out at neutral pH (6.0 - 8.0), at a temperature of 55 to 800C for 10 minutes or more preferably 30 to 180 minutes. The extracted protein suspension is precipitated at the isoelectric point, which results in the formation of protein aggregates from which the soy proteins are isolated. The product obtained has excellent coloring and very increased emulsifying properties.

 To date, oil cake, an abundant source of vegetable protein matter, is only valued through the preparation of livestock feed. The subject of the present invention is a simple, efficient and economical process allowing the production of surfactant proteins. These proteins have desirable characteristics in many applications in various fields (food, pharmaceutical and cosmetic).

 The object of the invention is to propose a new product, the surfactant proteins from oil cake, entirely natural, capable of being incorporated more easily into different types of preparation in various fields to serve in particular as technological ingredients.

 Another object of the invention is to obtain a protein preparation having increased functionality without the addition or introduction of salts, without overheating above the boiling temperature of water, and without the application of large forces. shear as obtained by centrifugal homogenization.

 Preferably, the process of the invention is carried out at a temperature between about 50 and 600C.

 The desired temperature can be reached by means of a double-shell structure of the container in which the suspension is kept.

 The object of the invention is to obtain a mixture of surfactant proteins from oilseed cake and in particular oil seeds such as: peanut, sunflower, sesame rapeseed, etc.

 Advantageously, this process according to the invention also uses sunflower and rapeseed meal, although these products rich in phenolic compounds are less accepted, the process according to the invention has another objective the elimination of these contaminants.

The invention also relates to the process for obtaining such a mixture of surfactant proteins. This process consists
- to put the cake protein mixture in form by heat treatment, then to subject this cake to a solid-solid separation, that is to say to separate the flour from the shell particles by means of a bed sorter fluidized,
- to carry out an ultra-fine grinding of flour by a second passage of the pre-crushed product in a press, the pressing of the hot vegetable matter which brings about the coagulation of soluble and insoluble proteins (albumins and globulins). This heating is carried out by a current of hot water at a temperature between 60 "C and 85" C. By using a temperature range between 60 "C and 85" C, the proliferation of mesophilic bacteria is avoided.

 According to the invention it has been found that the temperature control must also be carried out by adjusting the pressure during this step.

 The process therefore makes it possible, thanks to the temperature control, to avoid the precipitation of proteins. The maximum temperature value must be adjusted according to the humidity level and the type of plant material treated.

 The characteristics of the final product are variable according to the parameters chosen during this stage, and in particular as a function of the time / pressing temperature pair. It can be noted in this respect that the more we cook, the more the insolubility factor of proteins is increased.

 Different types of flour can be obtained by varying the grinding parameters or by setting the baking temperatures and times.

 These values will be chosen according to the characteristics of the protein preparations which it is desired to obtain.

This mixed surfactant protein obtained can be used as an ingredient in the following products:
- as a fat substitute in low-fat recipes
- in cold meats: for the preparation of terrine or sausage for example
- in cereal products: in bread-making, to enter into the composition of sandwich or special breads, or in pastry, biscuit and pasta,
- for sauces and / or cooked dishes;
- as a protein intake for light recipes;
In addition to its very good capacity for retaining water and fat, it has texturing properties and a neutral taste in food preparation.

 In cosmetology, they are used in the formulation of several products such as shampoos, cream, lotion, etc.

 In pharmacy, these surfactant proteins can be used in the formulation of excipients, they can also be used in dietetics and the treatment of genetic deficits, in particular in the assimilation of fat-soluble vitamins. This deficit is encountered in patients suffering from abetalipoproteinemia.

Method and device for transporting surfactant proteins
The preparation process shown diagrammatically in FIG. 1 is a process for the extraction of surfactant proteins from oil cake. First of all, the particles of hulls and cotyledon grains are separated by means of a sorter.

 This technique is very delicate to implement, it can advantageously be carried out by air separation techniques or by sieving. These means, conventional in the field of milling, allow proper separation of the elements. The result is a product with ultimate fine grinding (grinding).

 Oil cake is placed in a fluidized bed sorter, a fine flour with a particle size of a few hundred microns is obtained.

 The protein mixture is shaped by heat treatment, the protein mixture is dissolved by adding an aqueous phase at alkaline pH (water and sodium hydroxide solution), the protein phase is extracted by liquid-solid separation, using a filter.

 In a particular embodiment of a method according to the invention, the clarification will be carried out either by filtration (tangential microfiltration, microfiltration on filter press ...) in order to remove the insoluble protein residue, the residual lipids as well as mineral precipitates such as calcium phosphates or impurities of a non-protein nature (sugars, metals, phytates, phenolic compounds). For example, a filter press with frames and plates is used in the presence of a filter aid of the diatom type.

The filterability of the product being very good, the filtration system to be implemented is simple:
- a first membrane filtration with a porosity of approximately 20 clam.

 - a second membrane filtration whose porosity is approximately 3 ptm.

 Then the filtrate thus obtained is subjected after adjustment to an acid pH such as a pH of 4.5 to 5, to a second liquid-solid separation by microfiltration.

 The solubilized proteins are precipitated under conditions close to their isoelectric point (pH = 4.5) by lowering the pH between 3.8 and 6.0 with a food acid solution preferably citric acid at a temperature between 20 and 400C and then recovered by microfiltration before subjecting them to a sterilization and drying operation.

 According to a particle of the invention, after having dissolved the protein mixture in water, the solution thus obtained is subjected to a heat treatment at a temperature between 30 and 1000C, advantageously for a period of time less than 45 minutes at a pH close to neutrality between 7 and 8.5 so as to obtain an aqueous protein suspension.

 Liquid-solid separation is carried out by tangential microfiltration or microfiltration on a filter press. Filtration on a filter press with frames and plates gives the best results.

This heat treatment followed by a liquid-solid separation has the following advantages:
- destruction of most of the protein inhibitors;
- significant reduction in the contaminating mesophilic flora,
- elimination of free amino acids and other small molecules of a non-protein nature (lipids, sugars, urea, pigments);
- reduction in the ionic strength of the protein solution after elimination of the ions during the liquid-solid separation by filtration;
In order to limit the ionic strength in the final product, lime (Ca (OH) 2) will generally be chosen as the basis for controlling and maintaining the pH.

 The product thus filtered is collected in a sterile container before being subjected to dehydration. The elimination of water can be obtained either by lyophilization, or by atomization coupled or not with a preconcentration by evaporation under vacuum.

 The manner in which the invention can be implemented and the advantages which ensue therefrom will emerge more clearly from the example of embodiment which follows, given by way of indication and without limitation.

Claims (6)

 subjecting the cake to a solid-solid separation by means of a fluidized bed sorter.  I) Process for the production of a mixture of surfactant proteins from oil cake, characterized in that it comprises the following stages  shaped by heat treatment of the meal protein mixture, which results in the formation of an ultra-fine grind.  extraction of the aqueous protein phase by a liquid-solid separation through a pre-filtration membrane with a pore diameter equal to approximately 20 clam, then elimination of the particles and other molecules (sugars, residual lipids, pigments ...) .  solubilization of the proteins contained in the milling in an aqueous phase at alkaline pH,  solid-liquid separation by means of a microfiltration membrane with a porosity equal to approximately 3 μm, and recovery of a retentate formed from aggregates of surfactant proteins.  precipitation of proteins at their isoelectric point  drying of aggregates. 2) Method according to claim 1, characterized in that the shaping of the starting protein source comprises a heat treatment in a temperature range between 60 and 85 "C at initial pH. 3) Method according to one of claims 1 or 2 characterized in that the proteins formed by heat treatment are dissolved at pH values between 7 and 8.5, preferably between 7.5 and 8.0 at temperatures between 30 and 700C , preferably between 50 and 60 "C. 4) Method according to one of claims I to 3 characterized in that one proceeds to the precipitation of proteins by lowering the pH between 3.8 and 6.0, preferably between 4.0 and 5.0 by addition of food acid preferably citric acid , at a temperature between 20 and 40 "C, preferably at room temperature. 5) Method according to any one of the preceding claims, characterized in that the protein mixture formed is filtered by solubilization then precipitation on a frame press filter and trays in order to remove impurities of non-protein nature (lipids , sugars, metals, phytates, phenolic compounds ...). 6) Use of the mixed surfactant protein as obtained by the method according to one of claims 1 there as technological aid in the food, cosmetic or pharmaceutical field.