Abstract: The effectiveness of four different proteases in hydrolyzing high temperature rice bran meal for enzymatic extraction of alkali insoluble protein was compared to identify alkaline protease as the best choice. The effects of alkaline protease dose, temperature, pH and hydrolysis time on extraction efficiency were explored by one-factor-at-a-time design. Using orthogonal array design, the optimal conditions of alkaline protease dose, temperature, and pH were determined to be 300 U/g, 55 ℃, and 8.5, respectively. Under these conditions, the extraction yield of alkali insoluble protein was up to 28.9%.

Key words: high temperature rice bran meal, alkaline protease, protein extraction rate, alkali extraction