阅读说明：本技术 一种通过超高压辅助提高大豆分离蛋白溶解性的方法 (Method for improving solubility of isolated soy protein by assistance of ultrahigh pressure ) 是由 刘丹怡 杨红 王子欢 王语聪 谢智鑫 刘容旭 张莉丽 韩建春 于 2019-09-12 设计创作，主要内容包括：一种通过超高压辅助提高大豆分离蛋白溶解性的方法,属于大豆分离蛋白制备技术领域。本发明的目的是为了解决现有的大豆分离蛋白功能特性较差的问题,所述方法如下：将大豆分离蛋白和还原糖配成混合溶液,室温下在反应容器进行充分混合；将得到的混合溶液置于超高压装置中进行美拉德反应；将反应结束后的反应物进行水浴冷却即可。本发明相对于现有技术的有益效果是：本发明利用超高压可以改变蛋白质结构的特性,制备的大豆分离蛋白具有较好的溶解性,在压力达到200MPa时,其美拉德反应产物的溶解度达到最大86.48％。具有原料易得、成本低廉、高效低毒等特点。(A method for improving the solubility of isolated soy protein by the assistance of ultrahigh pressure belongs to the technical field of isolated soy protein preparation. The invention aims to solve the problem that the existing isolated soy protein has poor functional characteristics, and the method comprises the following steps: preparing soybean protein isolate and reducing sugar into a mixed solution, and fully mixing in a reaction container at room temperature; placing the obtained mixed solution in an ultrahigh pressure device for Maillard reaction; and (3) cooling the reactant after the reaction in water bath. Compared with the prior art, the invention has the beneficial effects that: the invention utilizes the characteristic that the ultrahigh pressure can change the protein structure, the prepared soybean protein isolate has better solubility, and the solubility of Maillard reaction products reaches 86.48 percent at the maximum when the pressure reaches 200 MPa. Has the characteristics of easily obtained raw materials, low cost, high efficiency, low toxicity and the like.)

1. A method for improving the solubility of isolated soy protein by the assistance of ultrahigh pressure is characterized in that: the method comprises the following specific steps:

the method comprises the following steps: preparing soybean protein isolate and reducing sugar into a mixed solution, and fully mixing in a reaction container at room temperature;

step two: placing the mixed solution obtained in the step one in an ultrahigh pressure device for Maillard reaction;

step three: and (3) cooling the reactant after the reaction in water bath.

2. The method of assisting in increasing the solubility of soy protein isolate by ultra high pressure as claimed in claim 1, wherein: in the first step, the protein content of the soybean protein isolate is more than or equal to 90 percent.

3. The method of assisting in increasing the solubility of soy protein isolate by ultra high pressure as claimed in claim 1, wherein: in the first step, the reducing sugar is flaxseed gum.

4. The method of assisting in increasing the solubility of soy protein isolate by ultra high pressure as claimed in claim 1, wherein: in the first step, the soy protein isolate is prepared into a solution of 20mg/mL by using a phosphate buffer solution, and a reducing sugar aqueous solution of 20mg/mL is added, wherein the mixing ratio is 1: 1, magnetically stirring for 2h at room temperature, and then storing for 12h in an environment at 4 ℃.

5. The method for assisting in increasing the solubility of soy protein isolate by ultra high pressure as claimed in claim 4 wherein: the pH of the phosphate buffer was 8.0.

6. The method of assisting in increasing the solubility of soy protein isolate by ultra high pressure as claimed in claim 1, wherein: and in the second step, the mixed solution obtained in the first step is transferred into a cooking bag and sealed, an ultrahigh pressure device is preset to 60 ℃, the cooking bag is placed in a high pressure cavity, and the pressure is adjusted to 100MPa, 200MPa or 300MPa for reaction for 24-72 h.

7. The method of assisting in increasing the solubility of soy protein isolate by ultra high pressure as claimed in claim 1, wherein: in the third step, after the reaction in the second step is finished and the pressure of the device is relieved, the mixed solution is immediately placed in an ice-water bath to stop the reaction, after cooling, the mixed solution is centrifuged for 10min at the temperature of 4 ℃ and 8000 Xg, and the supernatant is frozen and dried.

8. The method of assisting in increasing the solubility of soy protein isolate by ultra high pressure as claimed in claim 7 wherein: the freeze drying specifically comprises: pre-freezing at-40 deg.C for 40min, running at-40 deg.C for 100min, running at-35 deg.C for 100min, running at-30 deg.C for 300min, running at-25 deg.C for 300min, running at-15 deg.C for 300min, running at 0 deg.C for 100min, running at 10 deg.C for 100min, and running at 20 deg.C for 100 min.

9. A soy protein isolate produced by the process of any one of claims 1 to 8.

Technical Field

The invention belongs to the technical field of preparation of soybean protein isolate, and particularly relates to a method for improving the solubility of the soybean protein isolate by virtue of assistance of ultrahigh pressure.

Background

With the rapid development of food manufacturing industry in China, higher requirements are made on food additives taking soy protein as a base material, the soy protein can not only effectively increase the protein content in food, but also hopefully show certain functional characteristics such as solubility, foamability, emulsibility, gel property and the like in application, and the characteristics can effectively improve the functional characteristics of food such as taste improvement, elasticity increase, storage property improvement and the like. However, the functional properties of conventional soy proteins are relatively poor and sensitive to processing conditions, which greatly limits their use in many food systems. Therefore, strengthening or improving the functional properties of soy protein is an urgent problem to be solved in the food processing industry.

Disclosure of Invention

The invention aims to solve the problem of poor functional characteristics of the existing soybean protein isolate, and provides a method for improving the solubility of the soybean protein isolate under the assistance of ultrahigh pressure.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

a method for improving the solubility of isolated soy protein by the assistance of ultrahigh pressure comprises the following specific steps:

the method comprises the following steps: preparing soybean protein isolate and reducing sugar into a mixed solution, and fully mixing in a reaction container at room temperature;

step two: placing the mixed solution obtained in the step one in an ultrahigh pressure device for Maillard reaction;

step three: and (3) cooling the reactant after the reaction in water bath.

A soy protein isolate is prepared by the above method.

Compared with the prior art, the invention has the beneficial effects that: the invention utilizes the characteristic that the ultrahigh pressure can change the protein structure, the prepared soybean protein isolate has better solubility, and the solubility of Maillard reaction products reaches 86.48 percent at the maximum when the pressure reaches 200 MPa. Has the characteristics of easily obtained raw materials, low cost, high efficiency, low toxicity and the like.

Detailed Description

The technical solutions of the present invention are further described below with reference to the following examples, but the present invention is not limited thereto, and modifications and equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit of the technical solutions of the present invention, and the technical solutions of the present invention are covered by the protection scope of the present invention. The components used in the following examples are commercially available unless otherwise specified.

In the food industry, high pressure treatment differs from conventional thermal processing in that high pressure treatment acts on non-covalent bonds such as protein hydrogen bonds, ionic bonds, hydrophobic bonds, and the like, while hardly destroying covalent bonds of low molecular weight compounds such as amino acids, vitamins, aroma components, and the like, and thus can maximally maintain the nutritional value of food. Experimental research shows that the structure of the soybean protein is stretched under ultrahigh pressure treatment, the sulfydryl group is increased, the surface hydrophobicity is improved, and the subunit composition of the protein is changed. Meanwhile, the Maillard reaction is introduced under a proper high-pressure environment, along with moderately developed protein molecules, the opportunity of the reduction carbonyl reaction of the epsilon-amino of the protein and the polysaccharide is greatly increased, so that the progress of the Maillard reaction is influenced, and the structure and the functional property of the protein are further influenced.