Effects of Heat Treatment and Transglutaminase on the Gelation Properties of Glycosylated Oat Protein

Gelation of native oat protein and oat protein glycosylated with lactose was induced by heat or transglutaminase (TGase) treatment in order to investigate the effects of different induction methods on the gel properties and structure of oat protein. The results showed that compared with the heat-induced gel of oat protein, the elasticity, hardness, and water-holding capacity of three other oat protein gels were significantly improved (P < 0.05). The texture properties (elasticity, hardness and viscosity) and water-holding capacity of the TGase-induced gels were better than those of the heat-induced gels, and the texture properties and water-holding capacity of the glycosylated protein gels were significantly higher than that of the non-glycosylated protein gels (P < 0.05). The surface hydrophobicity of enzyme induced protein gel was higher than that of 2 kinds of heat-induced protein gel, respectively; the surface hydrophobicity of glycosylated modified protein gel was lower than that of non-glycosylated modified protein gel. Furthermore, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared (FTIR) spectroscopy, fluorescence spectroscopy and microstructure analysis proved that TGase could cause intermolecular or intramolecular cross-linking of oat protein to form macromolecules, and the TGase-induced gel had a denser three-dimensional network microstructure. This study shows that TGase can induce native and glycosylated oat protein more effectively compared with heat treatment, which provides a theoretical basis for the diversified development of oat flour.