JPH0154985B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a protein material with enhanced nutritional value by enzymatically bonding amino acids to an edible protein using transglutaminase. Conventionally, in order to supplement amino acids that are nutritionally deficient in natural proteins, the method used was to simply add and mix amino acids to proteins. However, the amino acid-added proteins obtained in this way are subject to significant wash-off and wastage during processing into food and feed, and for this reason, amino acids must be added in appropriate amounts by anticipating in advance a percentage of the required amount. . Furthermore, when amino acids are simply added, the taste and odor characteristic of amino acids are attached to foods, which limits their use as protein materials. Furthermore, the amino acids of amino acid-added proteins may be damaged by heating or freezing during food processing or cooking, and the amino acids may change or decompose during storage. The present invention aims to provide a fortified protein that does not have the above-mentioned disadvantages. That is,
The present invention provides a mixture of natural protein or (and) its decomposition products and amino acids for food or feed.
This is a method for producing a protein material with enhanced nutritional supplementation, which is characterized in that amino acids are introduced into protein or/and its decomposition product by the action of transglutaminase and an enzymatic chemical reaction. According to the present invention, a desired nutritionally enriched amino acid-binding protein material can be produced by combining various proteins and various amino acids,
In addition, since the products of the present invention have amino acids chemically bonded, there is no leakage and loss during processing, there is no foul taste or odor, and there is no decomposition during storage. Furthermore, since enzymes are used in the present invention, the binding reaction is carried out efficiently. The raw materials used in the present invention are natural proteins for food or feed, such as milk casein, soybean protein, wheat gluten, beef protein,
Examples include animal and vegetable proteins such as fish protein, rice protein, and corn protein. Further, protein decomposition products, such as protease decomposition products of the above-mentioned proteins, are also used as raw materials. Various types of amino acids can be used as the amino acids to be bound to proteins, and for example, methionine, cystine, cysteine, lysine, tryptophan, etc., for which nutritional supplementation is particularly important for proteins, can be preferably used. Amino acid derivatives, such as derivatives in which the carboxyl group is methylated or ethylated, are used. However, in the case of lysine, the ε-amino group binds to proteins, so there is no need to make it into a derivative. Transglutaminase is allowed to act on a mixture of these proteins and amino acids. In this enzymatic chemical reaction, deammonia occurs between the amide group of the glutamine residue of the protein or its decomposition product and the amino group of the amino acid as described below. A-(CH ₂ ) ₂ -CONH ₂ +H ₂ N-R -NH ₃ ---→ A-(CH ₂ ) ₂ -CO-NH-R (A: peptide chain R: amino acid residue) Transglutaminase is a calcium It is an enzyme that catalyzes a dependent acyl transfer reaction, and forms an amide bond between the amino group (acyl donor) of a glutamine residue in a protein or its degradation product and the amino group (acyl acceptor) in various compounds. to form. Transglutaminase was determined by the method of Connellan et al. [Connellan et al, J.Biol.Chem.246, 1093]
(1971)] from guinea pig liver;
It can also be obtained from the blood of cows and other animals. The method of the present invention is an enzymatic reaction that uses transglutaminase to introduce amino acids into protein molecules. As described above, transglutaminase is calcium dependent, so the introduction reaction requires the presence of calcium, and is usually carried out in the presence of calcium chloride. If desired, reducing agents such as dithiothreitol, cysteine, glutathione, mercaptoethanol, etc. can be added to activate and stabilize transglutaminase. Generally, 1 to 10 parts of protein is dispersed in 1000 parts of water, 2 to 10 parts of amino acids, and calcium chloride.
Add 0.6 parts and 0.02-0.10 parts of transglutaminase. The reaction is carried out with stirring at pH 6-8.5 and 120-40°C. Reaction time is 2-10 hours. After the reaction is completed, the reaction solution is treated in a conventional manner to obtain the target product. For example, after dialysis using an ultrafiltration device, the protein is subjected to spray drying, or the protein is precipitated with acid or alcohol, and the precipitate is dissolved or dispersed in water and then subjected to spray drying. Transglutaminase activity is stopped during the dialysis or precipitation process in the above procedure. The amount of amino acids introduced can be adjusted as appropriate by changing reaction conditions such as reaction time and calcium concentration. For example, the relationship between the amount of amino acid introduced and the reaction time is shown in Tables 1 and 2 below.

【table】

【table】

[Table] According to the present invention, it is possible to introduce various desired amino acids into various proteins, and it is possible to obtain a protein material having a well-balanced amino acid composition and excellent nutritional value. As shown in the table below, the products of the present invention are superior in protein efficiency and quality compared to conventional products that simply add amino acids.

【table】

【table】

[Table] In Tables 3 to 5 above, the unit of amino acid amount is g of amino acid/g of protein nitrogen, and protein efficiency is expressed as body weight gain/amount of protein intake. Sensory evaluation: 10 men, 10 women, total 20
This was obtained from the results of a taste and odor panel test. The present invention will be explained below using examples. Example 1 100g of wheat gluten was dispersed in 10Kg of water.
After adjusting the pH to 7.5, 6 g of calcium chloride and 15 g of dithiothreitol were added. To this, 30 g of lysine and 0.2 g of transglutaminase were added. The mixture was heated and maintained at 37°C, and the mixture was reacted for 5 hours with gentle stirring. This was dialyzed using an ultrafiltration device and then spray-dried to obtain 85 g of lysine-enriched wheat gluten. The obtained fortified wheat gluten was a white powder with a slight yellow tinge, and its properties were not significantly different from the starting material wheat gluten. The amount of lysine introduced was 83 mg per gram of wheat gluten. Example 2 Dissolve 100g of milk casein in 10Kg of water and adjust the pH to 7.5.
I made it. Add to this 6g of calcium chloride, 100g of methionine ethyl ester, and transglutaminase.
Added 0.3g. The mixture was kept at 37°C and reacted for 5 hours with gentle stirring. This was dialyzed using an ultrafiltration device and then spray-dried to obtain 83 g of white methionine-enriched milk casein. The amount of methionine introduced was 24 mg per gram of casein.

Claims (1)

[Claims] 1. It is characterized by introducing amino acids into the protein or (and) its decomposition product through an enzymatic chemical reaction by allowing transglutaminase to act on a mixture of natural protein for food or feed or (and) its decomposition product and amino acids. A method for producing nutritionally supplemented and fortified protein materials.