HU180425B - Process for the purification of casein hydrolysate - Google Patents

Abstract

<P> Process for the manufacture of products resulting from the hydrolysis of proteins and having improved properties. </ P> <P> Products obtained in a known manner by hydrolysis of proteins are subjected, in the form of dry powders having a water content of at most 8%, to extraction with solvents or mixtures of solvents. the solvents used being alcohols or mixtures of alcohols, mainly aliphatic alcohols, preferably methanol, ethanol, propanol and isopropanol. The invention is applicable to the manufacture of medicaments as well as to the formulation of synthetic dietary regimens. </ P>

Description

The present invention relates to a process for the purification of casein hydrolyzate. The casein hydrolyzate of the present invention is used in the preparation of balanced synthetic diets, infusion solutions, amino acid tablets for the treatment of chronic renal failure and preparations for the treatment of phenylketonuria.

It is known that products obtained by hydrolysis of proteins contain, in addition to the desired amino acid components and low molecular weight peptides, virtually all by-products of hydrolysis such as amines, ketonic acids, ammonium salts, and the like. [Food Trade Review 44, 16 (1974)]. Some of the excipients are a nuisance ⁰ impart flavor to the Metl protein hydrolyzate, which has a detrimental effect on the oral administration.

Previously, attempts have been made to improve the taste of the hydrolyzates by converting glutamic acid and aspartic acid present in the hydrolyzate to sodium salts with known flavoring effects by the addition of sodium hydroxides. This process is described in U.S. Patent No. 2,991,309.

According to German Patent No. 70,096, the perfume and aroma by-products formed during hydrolysis can be removed by distillation of a portion of the water 30 present in the reaction mixture by the simultaneous addition of distilled water. In the use of such hydrolysates, the presence of glutamic acid and aspartic acid is undesirable on the one hand, since they would represent ballast materials as non-essential amino acids, and on the other hand, according to known methods. perfume and flavoring by-products cannot be completely removed so that the use of flavor enhancers cannot be avoided. However, some patients treated with such formulations still feel disgusted by residual root taste (Infusionstherapie 3 (1976), 238-241 and 216-220).

It has been found that, even in smaller amounts, the products prepared according to German Patent EP 70 096, during the final stage of spray preparation or similar processes, have a root taste due to the temperature and the oxygen in the air.

In view of the recent increase in the use of casein hydrolyzate as a component of balanced diets for the treatment of chronic renal failure and phenylketonuria and in the preparation of infusion solutions, the known technical value-adding solution.

It is an object of the present invention to provide a process which allows removal of by-products of odor, taste and biological value that are produced during the process of making casein hydrolyzate.

The disadvantage of the solutions known so far is that they achieve only a taste-improving effect and do not result in an increase in biological value or the removal of additional by-products.

According to the present invention, the object is solved by the solvent extraction of the casein hydrolyzate prepared in the known manner (Food Trade Review 44, 16, 1974) in the form of a dry powder. application.

The process is practically carried out by heating the hydrolyzate of casein having a maximum water content of 8% obtained by spray drying or the like with a small amount of methanol or another suitable alcohol to the boiling point of said alcohol. Separation of the insoluble solids from the solvent is accomplished by suction filtration or centrifugation. The solid is then washed with a small amount of the alcohol used in the extraction and air-dried or otherwise suitably dried. The resulting casein hydrolyzate is odorless and odorless and does not contain amines, ammonium salts or ketoic acids. The biological value of the product obtained increases with the amount of by-products removed by increasing the proportion of essential amino acids relative to the parent product. The process of the present invention can also be applied to hydrolysates from which glutamic acid and aspartic acid have been removed and phenylalanine has been removed by known methods.

Example 1

Casein is known in the art [J. agric. chem, soc. Japanese Bull. 28.775 (1954)], such as dilute sulfuric acid, hydrolyze, remove the acid from the resulting solution, purify the solution with activated carbon and spray dry to obtain a dry powder. The product obtained is brownish-yellow in color and has a root-like flavor and aroma.

100 g of the casein hydrolyzate thus obtained is refluxed with 200 ml of methanol (10 minutes), the insoluble material is suctioned off, washed twice with 50 ml of methanol and air-dried.

Yield: 80 g practically colorless, odorless, odorless powdered casein hydrolyzate.

Essential amino acid content

Before treatment after treatment isoleucine 2.2% 2.8% leucine 5.8% 7.2% lysine 6.0% 6.2% threonine 3.0% 3.8%

histidine 2.0% 2.6% valine 2.7% 3.4% phenylalanine 2.3% 2.8% methionine 1.8% 2.3%

Example 2

Asparagine acid ¹⁰ and glutamic acid are removed from the casein solution hydrolyzed as described in the first example using a basic ion exchanger. Spray drying gives a dry product which is yellow in color and has a root-like odor and taste.

100 g of the casein hydrolyzate thus obtained is heated under reflux in ⁵ 200 ml of ethanol for 10 minutes, the insoluble material is suctioned off, washed twice with 50 ml of ethanol and air-dried.

Yield: 85 g of colorless, odorless and tasteless powdered hydrolyzate.

Essential amino acid content before treatment after treatment

isoleucine 2.6% 3.5% leucine 6.9% 7.9% lysine 6.5% 7.5% threonine 4.0% 4.6% histidine 2.5% 2.8% valine 3.5% 4.2% phenylalanine 3.5% 4.1% methionine 2.2% 2.6%

Example 3

According to the first example, 100 g of the dry powder obtained by hydrolysis followed by spray drying is refluxed for 10 minutes in 200 ml of isopropanol. After suctioning off the insolubles and washing with 100 ml isopropanol 10, the product is air dried.

Yield: 94 g hydrolyzate of slightly yellow, odorless and tasteless powder.

The proportion of essential amino acids increased by 5% relative to the product.

Example 4

According to Example 1, 100 g of dry powder obtained by hydrolysis followed by spray drying is heated under reflux for 10 minutes with 100 ml of methanol and 100 ml of ethyl acetate. The insoluble material is sucked off and air-dried.

Yield: 92 g lightly hydrolyzate of casein in the form of slightly discolored, odor 55 and odorless powder.

The proportion of essential amino acids increased by 6% compared to the starting product.

Example 5

According to Example 1, 100 g of dry powder obtained by hydrolysis followed by spray drying was stirred with 200 ml of ethanol for 15 hours at room temperature. The insoluble material is filtered off with suction and air-dried after washing with 300 ml of ethanol.

Yield: 86.5 g of casein hydrolyzate, which is a slightly yellowish, odorless and tasteless powder.

The proportion of essential amino acids increased by 10.2% compared to the starting product.

Claims (2)

PATENT CLAIMS: A process for the purification of casein hydrolyzate, characterized in that the casein hydrolyzate has a maximum water content of 8% in powder form. Extraction is carried out with a C 3 -C 3 alkanol or a mixture of a lower alkyl ester of a lower alkane carboxylic acid with a lower alkyl ester of from 3: 1 to 1: 3 at room temperature to the boiling point of the solvent used. Process according to claim 1, characterized in that the casein hydrolyzate is extracted with alkanols or mixtures of alkanol, preferably methanol, ethanol, propanol and / or isopropanol.