US-12616231-B2 - Heat coagulation gel strength regulating agent for egg white protein

Abstract

The purpose of the present invention is to provide a technology that enables control for increasing or decreasing the heat coagulation gel strength of egg white protein, and that has little effect on taste. This heat coagulation gel strength regulating agent for egg white protein contains a protein deamidase and can control the increase or decrease of the heat coagulation gel strength of egg white protein.

Inventors

• Kiyota Sakai

Assignees

• AMANO ENZYME INC.

Dates

Publication Date

20260505

Application Date

20211125

Priority Date

20201127

Claims (4)

1. 1 . A method for adjusting a strength of a gel obtained by thermal coagulation of an egg white protein, the method comprising: treating an egg white protein with a protein glutaminase; and thermally coagulating the egg white protein treated.
2. 2 . The method according to claim 1 , wherein the protein deamidase is used in an amount of 0.1 to 19 U with respect to 1 g of the egg white protein.
3. 3 . The method according to claim 1 , wherein the protein deamidase is used in an amount of 20 U or more with respect to 1 g of the egg white protein.
4. 4 . The method according to claim 1 , wherein the gel is in a food.

Description

TECHNICAL FIELD The present invention relates to a strength-adjusting agent for a gel to be obtained by thermal coagulation of an egg white protein. BACKGROUND ART An egg white protein has a property of forming a gel network by thermal coagulation, and this property is an important factor for determination of a texture characteristic of a food cooked using egg white. For cooking of an egg, a technique has been reported that enables use of an original coagulation property of an egg and, in addition, enables modification of an obtained cooked food. For example, Patent Document 1 shows that the tissue of an egg processed food can be densified by adding transglutaminase to a raw material mainly containing an egg and then cooking the raw material. Patent Document 2 shows that when an egg processed food such as a boiled egg is immersed in a solution containing transglutaminase, hardness and elasticity can be imparted to the egg processed food as compared with the case of treatment with no transglutaminase. A study on coagulation properties of eggs has reported that the jelly strength is increased by adding salt and decreased by adding sugar. PRIOR ART DOCUMENTS Patent Documents Patent Document 1: Japanese Patent Laid-open Publication No. 7-250651Patent Document 2: Japanese Patent Laid-open Publication No. 2017-175976 Non-Patent Document Non-Patent Document 1: Journal of Cookery Science of Japan Vol. 15, No. 2, (1982) p. 114-118 SUMMARY OF THE INVENTION Problems to be Solved by the Invention Thermal coagulation properties of the egg white protein are used in a wide range of cooked foods, and therefore it is considered that the versatility of the egg white protein can be further expanded if an increase/decrease (increase or decrease) of the strength of a gel to be obtained by thermal coagulation of the egg white protein can be controlled by a method without significant influence on the taste. However, a method using transglutaminase as in Patent Documents 1 and 2 is expected to have only an effect from an enzyme property of catalyzing a protein crosslinking reaction, that is, only an effect of increasing the strength of a gel to be obtained by thermal coagulation of the egg white protein, and a method using a condiment such as salt or sugar as in Non-Patent Document 1 has a large influence on the taste, thus resulting in a limited range of application in cooked foods. Therefore, an object of the present invention is to provide a technique that enables control of an increase/decrease (increase or decrease) of the strength of a gel to be obtained by thermal coagulation of the egg white protein and has a small influence on the taste. Means for Solving the Problem As a result of intensive studies, the present inventor has unexpectedly found that a protein deamidase (protein-glutaminase) can exhibit both effects of increasing and decreasing the strength of a gel to be obtained by thermal coagulation of the egg white protein according to the amount of the protein deamidase added. The present invention has been completed by further studies based on the above-described finding. That is, the present invention provides the invention of the aspects described below. Item 1. A strength-adjusting agent for a gel to be obtained by thermal coagulation of an egg white protein, the strength-adjusting agent including a protein deamidase. Item 2. The strength-adjusting agent for a gel to be obtained by thermal coagulation according to the item 1, to be used for producing a food containing a gel obtained by thermal coagulation of an egg white protein. Item 3. The strength-adjusting agent for a gel to be obtained by thermal coagulation according to the item 1 or 2, wherein the protein deamidase is used in an amount of 0.1 to 19 U with respect to 1 g of the egg white protein, the strength-adjusting agent is to be used for increasing a strength of a gel to be obtained by thermal coagulation of an egg white protein. Item 4. The strength-adjusting agent for a gel to be obtained by thermal coagulation according to the item 1 or 2, wherein the protein deamidase is used in an amount of 20 U or more with respect to 1 g of the egg white protein, the strength-adjusting agent is to be used for decreasing a strength of a gel to be obtained by thermal coagulation of an egg white protein. Item 5. A method for adjusting a strength of a gel obtained by thermal coagulation of an egg white protein, the method including: a step 1 of treating an egg white protein with a protein deamidase; anda step 2 of thermally coagulating the egg white protein treated. Item 6. A method for producing a material for gelation, the method including a step of treating a material containing an egg white protein using a strength-adjusting agent for a gel to be obtained by thermal coagulation of an egg white protein, the strength-adjusting agent including a protein deamidase, to obtain a material for gelation in which a strength of a gel to be obtained by thermal coagulation is