Use of proteases to enhance solubilization of rice bran proteins

Extraction yields of rice bran protein increased with the use of protease as the degree of hydrolysis (DH) increased, reaching 92% at a 10% DH value. Extraction of rice bran proteins was also carried out using limited proteolysis to 2% DH with Na2SO3 and/or SDS (0.2 mmol/g protein). Protein recovery increased from 74% to 80, 81, and 84% in the presence of Na2SO3, SDS and both, respectively. The presence of Na2SO3 or SDS yielded protein hydrolysates of a broader range of medium sized peptides with 78% of these protein hydrolysates having M-r of 11-68 kDa. Accordingly, use of proteases can be an efficient method for recovering high quality, value-added ingredients from the proteins of rice bran for food use.