Abstract: There usually are some shortcoming such as low protein extraction ratio and dark color during the rice bran protein extraction. The factors which caused these problems include extraction temperature, pH, ratio of solvent to material, and auxiliary agent amount. The central composite experiments and response surface analysis were used to optimize these factors. The experiments results showed that 60.4% protein extraction ratio and extraction supernatant color (L value) 56.7 were obtain under the optimized condition of temperature 40.8℃, ratio of solvent to material 12, pH 10.5, and auxiliary agent amount 0.5%. The actual protein extraction ratio was 59.5%, and L value 58.1, which showed that the optimized conditions were accurate.

Key words: rice bran protein, extraction, response surface analysis, optimization