DD223355A1 - PROCESS FOR TREATING PROTEINS - Google Patents

Abstract

The invention relates to a method for the treatment of proteins from plant, animal and / or microbial raw materials, preferably of protein isolates, for the purpose of structuring. The treated proteins are intended for use in meat and fish products, as well as for the preparation of ready-to-eat food preparations. According to the invention, an aqueous protein-containing dispersion is subject to prior physicochemical modification, if appropriate subsequently in the presence of a crosslinking reagent and / or complexing agent, freeze-structuring under certain defined conditions and the structural materials undergo thermal solidification.

Description

Inventor: Dr.'Gerhard Mieth

Dr. Christoph Schneider

Process for the treatment of proteins Field of application of the invention

The invention relates to a method for the treatment of proteins from plant, animal and / or microbial raw materials, preferably of protein isolates, for the purpose of structuring.

The structured proteins are especially suitable for the substitution of meat and fish products as well as for the production of special products, ie ready-to-eat food preparations.

Characteristic of the known technical solutions

One of the methods of choice for structuring proteins is compression molding (extrusion) and fiber formation (spinning), in the former case mainly defatted flours and concentrates, in the latter case, however, exclusively protein isolates.

In addition, the recovery of proteinates from protein-enriched preparations by freezing with a subsequent solidification is also known. For example, DE-AS 2 211 944 describes the production of a muscle tissue-like food from a protein suspension by controlled freezing with subsequent heating.

ben, and DE-AS 2 211 943 includes in a corresponding manner the production of a meat surrogate, wherein u. a. Meat and fish products are added. Similar solutions are based on other patents; these are different. each other by the chosen freezing and solidification conditions (heating, freeze-drying, 'alcohol treatment) and the type of raw materials and additives used.

As a particular disadvantage of this usually 'near the neutral point, d. H. On the one hand the structuring processes carried out at pH values of 6.0 to 8.0 indicate the low adsorption and emulsifying power of the end products, which is reflected in high losses of cooking water and fat during the thermal solidification. On the other hand, by cooling at pH values above and below the neutral point, end products having a high water and fat-binding capacity are obtained, but these are of more or less amorphous structure and not dimensionally stable, but instead gave pudding-like end products.

Another disadvantage of the latter methods is that water-soluble protein fractions (albumins) are not structurable, which is equally true for certain globulins outside the isoelectric point.

Object of the invention

The aim of the invention is therefore to develop a method for the treatment of proteins from protein-enriched, vegetable, animal and / or microbial raw materials, which enabled the production of structured, dimensionally stable products with variable structure and high water and fat binding at different pH values The invention is thus based on the object of

see process conditions under which protein-enriched products are transformed into such ordered structures that the final products have a high V / aer and Fettbindung with good structural stability and texture.

Explanation of the essence of the invention

According to the invention, aqueous dispersions of protein-enriched products of vegetable, animal and / or microbial raw materials, preferably protein isolates, after prior physico-chemical modification, then, optionally in the presence of an inorganic or organic Vernetzungsreagenzes, such as polyvalent metal salts, oxidizing agents or aldehydes, preferably calcium or Aluminum chloride, hydrogen peroxide and dialdehyde starch in concentrations of 0.1 to 1.0 % and / or polyanionic complexing agents such as polyphosphates, polysaccharides, isopolyacids and polycarboxylic acids, preferably alginates, pectinates, carboxymethylcelluloses and hexametaphosphates in concentrations of 1.0 to 5.0 % _} based on the protein content of the aqueous dispersions of a freezing at pH values between 2.0 and 8.0, preferably in the isoelectric range of the main protein fraction of 3.0 to 5.0 and temperatures of -5 to -50 ⁰ C with subsequent end thermal consolidation by heating to temperatures -100 ⁰ C, preferably at 1 atü overpressure subjected.

As has been found, a conformational change of proteins by a physico-chemical modification of freshly precipitated or dried protein isolates in aqueous suspension, at a protein content of the protein dispersant of 10 to 40 %, preferably 20 to 30%, by 1 to 10 hours exposure to acids or At room temperature and at pH values below the isoelectric point or above the neutral point, preferably at pH values between 2.0 and 3.0

or 9 to 10, O. as a necessary prerequisite with regard to obtaining textures with a high water and fat binding, good thermostability and variable texture, and it has also been found that the addition of crosslinking reagents or complexing agents makes this possible Also, such additives significantly improve the yield and biological value of the structates because of the intermolecular interactions between protein fractions having different molecular weights which suppress protein losses during the heating process and which are essential in achieving a broad range of pH values for thermally stable products Amino acids are enriched.

The structure of the final products depends essentially on the extent of protein denaturation during the physicochemical modification as well as on the environment chosen during freezing. For example, at pH values below the isoelectric point of the main protein fraction, granular, s-chamomile at pH values of the isoelectric point and fibrous structure at pH values above the isoelectric point result. In addition, the structure of the end products is influenced in a known manner by the time-temperature regime during freezing and is steered to a certain extent by freezing point depressing additives, preferably 1 to 10% saline or glycerol. This applies in a similar way to the heating process, in which, above all, a pressure application has a positive effect on the strength of the end products.

The structured proteins according to the invention are predestined additives for the substitution of meat products; but they also provide after incorporation of minced meat or fish and other ingredients, such as flavors, spices, salts and fats, before or after

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Freeze is an independent range of products suitable for direct consumption, which can be used, for example, in an assiette form for public catering.

The treatment operations according to the invention thus create favorable conditions and conditions for freeze structuring and thermobonding of protein isolates, at the same time purposefully influencing utilitarian properties such as the texture, juiciness and delicacy of the end products. »

The invention will be explained in more detail with reference to the following embodiments.

embodiments example 1

A 15% dispersion of a soybean protein isolate obtained by extraction with dilute sodium hydroxide solution at pH 8.0 and precipitation at pH 4.0 is incubated with dilute hydrochloric acid at pH 3.0 with addition of 0.1% after 6 hours incubation. Calcium chloride and the pH of the pH to 4.5 at -20 ⁰ C frosted and solidified by heating for 15 min at 1 atü. The resulting end product has a fine-fiber structure.

Example 2

A dispersion of canola protein obtained by extraction with 5% saline solution, concentrated by ultrafiltration to a protein content of 10 %, is incubated with dilute sulfuric acid at pH 2.5 after addition of 2 % sodium alginate and the pH is restored after 1 hour incubation 3.5 at -40 ⁰ C frosted and heated to 100 ⁰ G for 30 min.

The resulting end product has a spongy structure.

Example 3

A protein isolate of defatted sunflower seeds obtained by extraction with 0.5% sodium sulfite solution at pH 8.0 and precipitation at pH 4.0 is incubated with lactic acid at pH 4.0 with addition of 0.1 % hydrogen peroxide and recovery of pH after 10 hours incubation Value 'to 5.0 at -20 ⁰ G and then heated to 1 atm for 20 min.

The resulting end product has a coarse-fiber structure. ,

Example 4 '

A 25 parts by weight acid-precipitated casein contained pro-. teindispersion is incubated for 2 h and dilute sodium hydroxide solution at a pH value of 9.0 to 5.5 frosted comminuted with addition of 75 parts by weight of beef, 10 parts by weight of lard and other ingredience at -50 ⁰ C after resetting the pH and- Heated to 100 ⁰ G for 40 min.

Da3 resulting Bndprodukt has a flaky-fine-fiber structure.

Example 5

A field bean protein solution obtained by aqueous extraction of seed flour at pH 9.5 for 2 hours is isoelectrically precipitated at pH 4.2 by means of dilute sodium hydroxide solution. The separated precipitate is slurried with a little water, adjusted to pH 3.5 with dilute hydrochloric acid, frosted after addition of 0.5% calcium chloride at -25 G and solidified by heating to 100 ° C for 30 min.

The resulting product has a fine fiber structure.

Example 6

A by 4 hours aqueous extraction of seed flour at

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pH 2.0 faba bean protein solution obtained is "subject at pH 5.0. The separated precipitate is'" with milk of lime precipitation frozen at -30 ⁰ C and solidified by 20 min heating at 100 ⁰ C. The resulting end product has a leafy structure. * ·

Example 7

A 20 parts by weight soy protein isolate protein dispersion contained is incubated for 1 h with diluted hydrochloric acid at a pH of 4.0, comminuted meat and other Pisch ingredience mixed with 80 parts by mass of under pH adjustment to 6.0, frozen at -10 ⁰ for 20 min and G heated at 1 atm.

The final product has a scaly-coarse-fiber structure.

Claims (6)

Brfindungsansprüche •1. A process for the treatment of proteins by freezing and heating the dispersions of protein-enriched products from plant, animal and / or microbial raw materials, preferably Proteiriisolate, characterized in that aqueous protein-containing dispersions after prior physico-chemical 'modification then optionally in the presence of a crosslinking reagent and / or complexing agents , "at pH values between 2.0 and 8.0, preferably in the isoelectric range of the main protein fraction, from pH 3.0" to 5.0, of a freeze structure and the structures are subjected to thermal consolidation. 2. The method according to item 1, characterized in that the physico-chemical modification by 1 "to lOhr treatment with acids" at pH values between 2.0 and 3.0 or alkalis at pH values between 9.0 and 10, 0 and temperatures of 15 to 60 ⁰ C takes place. 3. The method according to item 1 and 2, characterized in that the freezing at temperatures of -5 to -50 C in the presence of inorganic or organic crosslinking reagents, such as polyvalent metal salts, oxidizing agents and aldehydes, preferably calcium and aluminum chloride, hydrogen peroxide and dialdehyde starch in concentrations of 0.1 to 1.0 % and / or polyanionic complexing agents, such as polyphosphates, polysaccharides, isopolyacids and polycarboxylic acids, preferably alginates, pectinates, carboxymethylcelluloses and hexametaphosphates in concentrations of 1.0 to 5.0 %, based on the protein content of the aqueous dispersion , he follows. 4 · Method according to item 1 "to 3, characterized in that the heating to tempera
at 1 atm. that the heating to temperatures ^ 100 ⁰ C, preferably 5. The method according to item 1 to 4, characterized in that the protein dispersion before or after freezing minced meat or minced fish and ingredients, such as flavors, spices, fats and salts, are added. 6. Method according to item 1 to 5, characterized in that the protein content of the protein dispersion 10 to 40%, - Preferably 20 to 30 %, is.