Comparison of Different Physical Technique-Assisted Alkali Methods for the Extraction of Rice Bran Protein and its Characterizations

Ultrasonic, homogenization and microwave were used to assist alkali extraction of rice bran protein, respectively, and the characterizations of rice bran protein were also evaluated. The results of this study showed that the highest extraction yield of protein reached 57.89 % by using ultrasonic-assisted alkali method (U-AM), while only it was 43.74 % by microwave-assisted alkali method (M-AM). Both U-AM and homogenization-assisted alkali methods (H-AM) could effectively improve some properties of proteins such as oil absorption capacity, emulsion stability and foaming capacity, and the effects of ultrasonic were better than those of homogenization. However, protein solubility, water absorption capacity, emulsifying activity and foaming stability were subject to different degrees of impairments by using various physical technique-assisted alkali methods (AMs). Moreover, physical processing also has exhibited appreciable influence on sulfhydryl and disulfide bond contents. Taking all these factors into consideration, ultrasonic-assisted alkali method was a potential method for the extraction of rice bran protein.