高温米糠粕制备米糠多肽的研究

Preparation of rice bran peptide from high-temperature rice bran meal

摘要：以高温米糠粕为原料，采用碱溶酸沉法制取米糠蛋白，并将米糠蛋白用碱性蛋白酶水解制备米糠多肽。在单因素实验的基础上，通过二次回归正交旋转组合设计确定最佳的水解条件为：水解温度55℃，加酶量0．3％（占高温米糠粕的质量），pH9．6，水解时间3h。在最佳水解条件下，米糠蛋白水解度为10．3％。所得米糠多肽粗蛋白含量为85．7％，蛋白质分散指数（PDI）为76．4％，氮溶解指数（NSI）为64．1％，相对分子质量在180～3000之间的米糠多肽占78．88％。

Using high - temperature rice bran meal as raw material, rice bran protein was extracted by alkaline extraction and acid precipitation, then rice bran protein was hydrolyzed to prepare rice bran pep- tide by alkaline protease. On the basis of single factor experiment, the hydrolysis conditions were opti- mized by quadratic regression orthogonal experiment as follows：hydrolysis temperature 55 ℃, enzyme dosage 0.3 % （ based on the mass of high - temperature rice bran meal）, pH 9.6, hydrolysis time 3 h. Under the optimal conditions, the hydrolysis degree of rice bran protein was 10.3%, the crude protein content of rice bran peptide was 85.7% , protein dispersion index （PDI）was 76.4%, nitrogen dissolving index（NSI） was 64.1% , and relative molecular weight of rice bran peptide between 180 and 3 000 ac- counted for 78.88%.