Physicochemical Properties and Functionality of Rice Bran Protein Hydrolyzate Prepared from Heat-stabilized Defatted Rice Bran with the Aid of Enzymes

Molecular size, thermal properties, hydrophobicity, nitrogen solubility, and emulsifying and foaming properties were determined for protein products from heat-stabilized defatted rice bran. The freeze-dried and spray-dried proteins had molecular sizes between 6.5 to 66.2 kDa; denaturation temperatures of 84.1 and 84.6 °C, enthalpies of 2.5 and 2.37 J/g, hydrophobicities of 20677 and 22611, maximum solubilities of 66.3% and 66.1% at pH 12.0, emulsifying capacities of 0.19 and 0.18, emulsion stabilities of 16.5 and 17.3 min, foam capacities of 4.0 mL and 4.2 mL, and negligible foam stabilities. These results demonstrated that the extracted rice bran protein has potential as a nutraceutical ingredient in food applications.