SOYBEAN PROTEIN HYDROLYSATE, ITS PREPARATION METHOD AND ITS USE

摘要

PURPOSE: A polypeptide mixture manufactured by hydrolyzing a 7S component and a 11S component of soybean selectively is provided which has a good emulsifying property and foamability. CONSTITUTION: For a polypeptide mixture, a soybean protein containing both a 7S component(beta-conglycinin) and a 11S component(glycinin) is used as a substrate. The 7S component is hydrolyzed selectively by the first decomposition reaction and then the 11S component is hydrolyzed by the second decomposition reaction. Preferable the substrate is a separation soybean protein. A low denaturation defatted soybean having a nitrogen solubility index of above 60 is dipped in water at 6.5-8.0 pH, extracted at below 60°C to remove a soybean curd residue. 1-30% Protein solution of the low denaturation defatted soybean as the substrate is added with 0.001-1% protein hydrolysis enzyme based on the substrate solid matter, hydrolyzed selectively at below 45°C for below 4 hr. at 1.8-2.5 pH until solubility by 0.22M TCA gets to 10-50% within 10 min to 2 hr. to give the polypeptide. The polypeptide has a molecular weight of 5,02000-35,000, a solubility of 30-90% by 0.22 M TCA, and a foamability of above 250. The polypeptide is useful for ices, a meringue, a spread paste, a drink, a starch product, and other food manufactures.