Inhibiting browning in preparation process of rice bran protein peptides and bleaching

Rice bran protein peptides were prepared by enzyme hydrolyzing protein isolates, that were refined by inhibiting browning reaction occurred in the preparation process, clarification and decolorization. The optimal browning inhibitor was with 0.15% citric acid, 0.15% L-cysteine and 3.0% ascorbic acid in rice bran protein solution during the preparation process, the pigment inhibition rate was 80.8%, the degree of hydrolysis was7.42% and nitrogen solubility index was 92.46%. Best clarifying conditions of enzyme inactivation process were as follows:pH=4.0, temperature 100℃ for 10min, centrifugal time was 3000r/min 20min, transmittance of peptides was 89.12%. Optimum conditions of decolorizing adsorbent with powdered activated carbon were as follows:the dosage of powdered activated carbon was 3.0%, pH=4.0, decolorization temperature was 60℃, adsorption time was 50min. Under these conditions, the decoloration rate reached 81.45%, the loss rate of peptides was10.11%.