Preparation of rice protein by two-step method of alkaline extraction and enzymatic hydrolysis

Broken rice was processed by two-step method of alkaline extraction and enzymatic hydrolysis, for preparing purer rice protein. The impact factors on the extraction rate of rice protein were studied, including rice flour granularity, pH value, temperature, the ratio of water to flour and time. The results indicate that the better process conditions for preparing rice protein with alkali are as follows: rice flour of 80 mesh, pH 11.0, 50℃, the ratio of water/flour is 8, 120 min. α-amylase is utilized to purify rice protein, the rational conditions of enzymatic hydrolysis are that the ratio of enzyme/protein is 60 U/g, pH 6.0, 50℃ and 30 min. Rice protein with the ratio of extraction 73.22% and purity 88.75% is prepared.