Continuous enzyme crosslinking modifying colloidal particle characteristics and interface properties of rice bran protein to improve the foaming properties

Abstract

The improvement of rice bran protein (RBP) foaming properties by continuous Transglutaminase (TGase) enzymatic cross-linking was studied and the related mechanism was analyzed. Under the conditions of enzyme addition of 0.5 kat/kg of protein and 3 h of enzyme crosslinking time, the foam capacity value and foam volume ratio of BPR were increased to 375% and 79.45% respectively and the liquid drainage rate of RBP samples foam system was decreased. Particle size distribution, zeta potential and surface hydrophobicity indicated that TGase treatment has changed the surface properties and aggregation state of RBP affecting the adsorption of TGase treated RBP on the interface. Meanwhile circular dichroism and intrinsic fluorescence suggested that TGase treatment made the tertiary structure of RBP aggregation more compact. The behavior of the air-water interface revealed that compared to native RBP, TGase cross-linked RBP exhibited a faster and more complex adsorption process, and a higher surface dilatational modulus. Enzyme cross-linked RBP particles mainly stabilized the interfacial membrane by Pickering mechanism, and TGase could catalyze cross-linking of RBP at the interface to enhance the elastic modulus of the interface. This study provides theoretical support for application of protein particles prepared by TGase enzymatic cross-linking in foamed foods.