Phosvitin-wheat gluten complex catalyzed by transglutaminase in the presence of Na2SO3: Formation, cross-link behavior and emulsifying properties

Phosvitin (PSV) is considered as a good emulsifier, although it has a low proportion of hydrophobic regions and steric hindrance. Wheat gluten (WG) possesses excellent hydrophobicity and macromolecular network structure. In this work, WG was subjected to a series of Na 2 SO 3 solution, followed by cross-linking with PSV under transglutaminase (TGase) catalyzation. The results showed that Na 2 SO 3 could break disulfide bonds of WG and increase its solubility from 7.33% to 42.82% with 1200 mg/L of Na 2 SO 3 . Correspondingly, the cross-linking degree was significantly enhanced. Compared to PSV, the cross-linked PSV-WG exhibited a higher surface hydrophobicity and thermal stability, with a lower zeta potential and apparent viscosity. The emulsifying activity of PSV-WG reached 17.42, 20.63 and 20.28 m 2 /g with Na 2 SO 3 concentration of 300, 600 and 900 mg/L, which were all higher than that of PSV (15.19 m 2 /g). This work provided a novel strategy to elevate emulsifying properties of PSV by cross-link reaction.