GB1595499A

GB1595499A - Protein hydrolysates

Info

Publication number: GB1595499A
Application number: GB5113577A
Authority: GB
Original assignee: Berlin Chemie AG
Current assignee: Berlin Chemie AG
Priority date: 1976-12-28
Filing date: 1977-12-08
Publication date: 1981-08-12
Also published as: FR2376158A1; FI773940A; SE7714796L; HU180425B; FR2376158B1; SU944529A1; DD141235A3; BG40982A1; CS189550B1; DE2751438A1; YU315277A

Description

(54) PROTEIN HYDROLYSATES (71) We, VEB BERLIN-CHEMIE, of 125-127, Glienicker Weg, 1199 Berlin, German Democratic Republic, a Corporation organised under the laws of the German Democratic Republic, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention is concerned with a process for the production of protein hydrolysates with improved properties.

The protein hydrolysates produced by the process according to the present invention can be used for the production of balanced synthetic diets, for the production of infusion solutions, of amino acid tablets for the treatment of chronic kidney insufficiency and for the production of preparations for the treatment of phenylketonuria.

The products produced in known manner by the hydrolysis of proteins contain, in addition to the desired proportions of amino acids or also of low molecular weight peptides, practically all by-products formed by the hydrolysis, such as amines, keto acids, ammonium salts and the like. A part of the accompanying materials imparts to the protein hydrolysates an unpleasant taste which is disadvantageous for oral administration. Attempts have already been made to improve the taste of hydrolysates by adding sodium hydroxide in order to convert the glutamic acid and aspartic acid present in the hydrolysates into their sodium salts, the taste-improving effect of which is known. This process is disclosed, for example, in U.S. Patent Specification No. 2,991,309. Furthermore, according to German Democratic Republic Patent Specification No. 70096, the odour- and taste-forming by-products formed by the hydrolysis can be removed by distilling off part of the water present for the hydrolysis in the reaction mixture, with simultaneous replenishment of the water distilled off. The other by-products are not removed. With regard to the use of such hydrolysates, on the one hand, the presence of glutamic acid and of aspartic acid is not desired since they are non-essential amino acid ballast materials and, on the other hand, as is known from experience, by means of the known methods, in such a complete removal of taste- and odour-forming by-products, it is not possible to omit the use of taste-correcting materials. However, even then, some of the patients treated with such preparations show a distaste for the remaining spicy flavour (see Infusionstherapie, 3, 238-241 and 216-220/ 1976).

As is known from experience, there is again formed, albeit in small amounts, in the preparations produced according to German Democratic Republic Patent Specification No.

70096, in the case of the spray drying or like process employed in the end stage of the production, a spicy flavour due to the action of temperature and of atmospheric oxygen.

Having regard to the recent increased use of protein hydrolysates as components of balanced diets, for the treatment of chronic kidney insufficiency, as well as of phenylketonuria, and for the production of infusion solutions, the known technical solutions to the problem do not satisfy the requirements demanded of protein hydrolysates with regard to their taste properties or, with regard to increasing the biological value, a technical solution to the problem has hitherto not been known.

It is an object of the present invention to provide a process which enables the by-products formed in the course of the production of protein hydrolysates, which influence the odour, taste and biological value, to be removed.

The disadvantages of the previously known solutions to the problem are that only a taste-improving effect is achieved but an increase of the biological value, as well as the removal of further by-products, does not take place.

Thus, according to the present invention, there is provided a process for the production of protein hydrolysates with improved properties, wherein a protein hydrolysate produced in known manner is, in the form of a dry powder, extracted with at least one alcohol or with an alcohol-containing mixture, followed by recovery of the undissolved solid material.

The alcohol used can be an aliphatic alcohol, for example, methanol, ethanol, n-propanol or isopropanol.

The alcohol or alcohol mixture can, if desired, also contain at least one other solvent miscible therewith, such as an ester of an aliphatic alcohol with an aliphatic carboxylic acid, such as ethyl acetate.

A protein hydrolysate obtained by spray drying or a similar method and having a water content of at most 8% by weight, is heated with a little methanol or some other appropriate alcohol up to the boiling point of the alcohol in question. The separation of the solid material which remains undissolved from the solvent can be carried out, for example, by suction filtration or by centrifuging. The solid material is thereafter washed with a small amount of the same alcohol and dried, for example, in the air.

The protein hydrolysate thus obtained is odourless and tasteless and does not contain any amines, ammonium salts or keto acids. The biological value of the product obtained is increased corresponding to the amount of by-products removed because the proportion of essential amino acids increases with reference to the starting material.

The process according to the present invention can also be used for those hydrolysates from which, in the course of production, glutamic acid and aspartic acid have been removed or from which phenylalanine has been removed.

The present invention also provides compositions containing a protein hydrolysate produced by the new process, in admixture with a non-toxic, pharmacologically acceptable solid or liquid diluent or carrier. Such compositions can be in the form of, for example, tablets, dragees, granulates, solutions or suspensions.

The following Examples are given for the purpose of illustrating the present invention: Example 1 A protein, for example casein, is hydrolysed in known manner by boiling with, for example, dilute sulphuric acid, the acid is removed from the solution obtained and a dry powder is produced by spray drying. The product obtained is brownish-yellow in colour and has a spicy odour and taste.

100 g. of the protein hydrolysates obtained in this maner are heated under reflux for 10 minutes with 200 ml. methanol and the undissolved material is filtered off with suction, washed twice with 50 ml. amounts of methanol and dried in the air.

There are obtained 80 g. of protein hydrolysate in the form of a practically colourless, odourless and tasteless powder. The essential amino acid content before and after the treatment is as follows: amino acid 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.

A solution of a protein hydrolysed in known manner according to Example 1 is freed from aspartic acid and glutamic acid by means of a basic ion exchanger. A dry powder is obtained by spray drying, which powder has a yellow colour and possesses a spicy odour and taste.

100 g. of the protein hydrolysate so obtained are heated under reflux for 10 minutes with 200 ml. ethanol, the insoluble material is filtered off with suction, washed twice with 50 ml.

amounts of ethanol and dried in the air.

There are obtained 85 g. of protein hydrolysate in the form of a colourless, odourless and tasteless powder. The essential amino acid content before and after the treatment is as follows: amino 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.

100 g. of a dry powder obtained according to Example 1 by hydrolysis and subsequent spray drying are heated under reflux for 10 minutes with 200 ml. isopropanol. After filtering off with suction the undissolved material and thereafter washing it with 100 ml.

isopropanol, it is dried in the air.

There are obtained 94 g. of protein hydrolysate in the form of a pale yellowish, odourless and tasteless powder.

The proportion of essential amino acids is increased by 5% in comparison with the starting material.

Example 4 100 g. of a dry powder obtained according to Example 1 by hydrolysis and subsequent spray drying are boiled under reflux for 10 minutes with a mixture of 100 ml. methanol and 100 ml. ethyl acetate. After filtering off with suction the undissolved material, it is dried in the air.

There are obtained 92 g. of protein hydrolysate in the form of a slightly coloured, tasteless and odourless powder.

The proportion of essential amino acids is increased by 6% in comparison with the starting material.

WHAT WE CLAIM IS: 1. Process for the production of protein hydrolysates with improved properties, wherein a protein hydrolysate produced in known manner is, in the form of a dry powder and with a water content of not more than 8% by weight, extracted with at least one alcohol or with an alcohol-containing mixture, followed by recovery of the undissolved solid material.

2. Process according to claim 1, wherein the alcohol is an aliphatic alcohol.

3. Process according to claim 2, wherein the aliphatic alcohol is methanol, ethanol, n-propanol or isopropanol.

4. Process according to claim 1 for the production of protein hydrolysates with improved properties, substantially as hereinbefore described and exemplified.

5. Protein hydrolysates with improved properties, whenever produced by the process according to any of claims 1 to 4.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

Example 2.

A solution of a protein hydrolysed in known manner according to Example 1 is freed from aspartic acid and glutamic acid by means of a basic ion exchanger. A dry powder is obtained by spray drying, which powder has a yellow colour and possesses a spicy odour and taste.

100 g. of the protein hydrolysate so obtained are heated under reflux for 10 minutes with 200 ml. ethanol, the insoluble material is filtered off with suction, washed twice with 50 ml.

amounts of ethanol and dried in the air.

There are obtained 85 g. of protein hydrolysate in the form of a colourless, odourless and tasteless powder. The essential amino acid content before and after the treatment is as follows: amino 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.

100 g. of a dry powder obtained according to Example 1 by hydrolysis and subsequent spray drying are heated under reflux for 10 minutes with 200 ml. isopropanol. After filtering off with suction the undissolved material and thereafter washing it with 100 ml.

isopropanol, it is dried in the air.

There are obtained 94 g. of protein hydrolysate in the form of a pale yellowish, odourless and tasteless powder.

The proportion of essential amino acids is increased by 5% in comparison with the starting material.

Example 4

100 g. of a dry powder obtained according to Example 1 by hydrolysis and subsequent spray drying are boiled under reflux for 10 minutes with a mixture of 100 ml. methanol and 100 ml. ethyl acetate. After filtering off with suction the undissolved material, it is dried in the air.

There are obtained 92 g. of protein hydrolysate in the form of a slightly coloured, tasteless and odourless powder.

The proportion of essential amino acids is increased by 6% in comparison with the starting material.

WHAT WE CLAIM IS: 1. Process for the production of protein hydrolysates with improved properties, wherein a protein hydrolysate produced in known manner is, in the form of a dry powder and with a water content of not more than 8% by weight, extracted with at least one alcohol or with an alcohol-containing mixture, followed by recovery of the undissolved solid material.
2. Process according to claim 1, wherein the alcohol is an aliphatic alcohol.
3. Process according to claim 2, wherein the aliphatic alcohol is methanol, ethanol, n-propanol or isopropanol.
4. Process according to claim 1 for the production of protein hydrolysates with improved properties, substantially as hereinbefore described and exemplified.
5. Protein hydrolysates with improved properties, whenever produced by the process according to any of claims 1 to 4.
6. Balanced synthetic diets, infusion solutions, amino acid tablets for the treatment of

chronic kidney insufficiency and compositions for the treatment of phenylketonuria, comprising a protein hydrolysate according to claim 5.
7. Compositions comprising a protein hydrolysate according to claim 5, in admixture with a non-toxic, pharmacologically acceptable solid or liquid diluent or carrier.