Soy Peptides, Soy Peptides

Peptides are linear polymers of amino acids. Usually, those with more than 50 amino acid residues are called proteins, and those with less than 50 amino acid residues are called peptides (the national soybean peptide powder standard sets the molecular weight of soybean peptides to be no greater than 10,000, 10,000 molecular weight peptide chain contains about 90 amino acid residues).

Soy peptides and soy peptides are obtained by hydrolyzing soy protein using modern biotechnology, and their amino acid composition is the same as that of soy protein. Generally speaking, there is no strict distinction between soybean peptides and soybean peptides.

Compared with traditional soy protein, although the production process of soy peptide is more complicated and the cost price is higher, it is easy to dissolve, digest and absorb, and can quickly supply energy to the body, without protein denaturation, no bey odor, no residue, and liquid viscosity. It has the characteristics of low sex and non-coagulation when heated, especially with unique physiological functions such as lowering serum cholesterol, lowering blood pressure and promoting fat metabolism. Therefore, soy peptide is a new type of soybean deep-processed product and nutrient with higher quality than soy protein. It has shown attractive development and application prospects in the fields of food, medicine, daily chemical industry and so on.

Since soy peptides are hydrolyzed from soy protein, in addition to the main component of soy peptides, soy peptides also contain unhydrolyzed soy protein, hydrolyzed products of larger molecular weight, and free amino acids formed by hydrolysis. Unhydrolyzed soy protein and hydrolyzed products with larger molecular weight have the shortcomings of soy protein, which are difficult to dissolve and digest and absorb, while free amino acids do not have the unique physiological functions of soy peptides. Therefore, the amount of unhydrolyzed soy protein, larger molecular weight hydrolysate, and free amino acids in soy peptides are key factors that determine the quality of soy peptides. Therefore, it is necessary to control the unhydrolyzed soy protein, larger molecular weight hydrolysates and free amino acids in soy peptides. The amount of amino acids.

Soy peptide content is obtained by checking the content of acid-soluble protein and free amino acid in the product, and then calculating the difference between them. Acid-soluble protein refers to the soluble protein that can be dissolved in 15% TCA (trichloroacetic acid) solution. The unhydrolyzed soy protein and larger molecular weight hydrolysate in the soy peptide are removed in the measurement. The result shows that the soy peptide and the The total amount of free amino acids, and then the free amino acid content is determined. The difference between the acid-soluble protein content minus the free amino acid content is the soybean peptide content.

In addition, the production process of soy peptides inevitably produces a certain bitterness and saltiness. The degree of bitterness and saltiness is an important factor affecting the quality of soy peptides. The degree of bitterness and saltiness of soy peptides must be controlled.

Soy peptides have been mentioned in the country for more than 10 years, and now a number of companies have produced products and have formed relevant industry standards and national standards. However, due to the backward process, the product quality is poor (poor taste, peculiar smell, high content of non-acid-soluble protein and free amino acid, low content of acid-soluble protein, etc.), and the product quality is uneven. The current soybean peptide standards do not require important indicators such as free amino acid content, bitterness, and salty taste. The requirements for key indicators of acid-soluble protein are low. The highest requirement is that the acid-soluble protein is less than 90% of the total protein, but it can be as low as below. 65% of the total protein contains a large amount of non-acid-soluble protein, which greatly restricts the application field of the product (such as the application of soy peptides in beverages will cause turbidity, precipitation, etc.), thereby greatly reducing its added value and serious This has affected the market acceptance of soy peptide products and has become the main reason why domestic soy peptides are difficult to be accepted by the domestic and foreign markets.