Wheat bran arabinoxylan and bovine serum albumin conjugates: Enzymatic synthesis, characterization, and applications in O/W emulsions

Wheat bran arabinoxylan-bovine serum albumin (WBAX-BSA) conjugates were prepared via enzymatic synthesis using horseradish peroxidase (HRP) and H2O2 as catalysts. The conjugates were characterized by ultraviolet-visible spectroscopy (UV-vis), high-performance size exclusion chromatography (HPSEC), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The feasibility of its application in stable emulsions was also assessed. UV-vis results revealed that phenolic acid in WBAX and aromatic amino acids in BSA were implicated in the enzymatic synthesis of the WBAX-BSA conjugate with the optimal WBAX:BSA mass ratio of 3:2. HPSEC results confirmed the intermolecular interactions between WBAX and BSA and the molecular weight of WBAX-BSA (2673 ± 16 kg/mol) was higher than that of control groups. Compared with the WBAX/BSA physical complexes, the WBAX-BSA conjugates had higher apparent viscosity (0.08-0.24 Pa.s), denser structure, larger particle sizes (33.5 ± 5.7 nm), and improving emulsifying properties in oil in water (O/W) emulsion system under different environmental stresses. The preparation of the enzymatic conjugates not only provides novel O/W emulsion systems but also improves processed food manufacturing processes that require efficient emulsification.