Effect of Glutamine Transaminase Cross-Linking on Physicochemical and Processing Properties of Lentinus edodes Protein

In order to develop and utilize Lentinus edodes protein, the effect of glutamine transaminase (TGase) crosslinking on the physicochemical and processing characteristics of L. edodes protein was studied. The results showed that the addition of 0%–20% TGase gradually reduced the contents of total thiol, free thiol and β-sheet of L. edodes protein, while the fluorescence intensity, particle size, β-turn content and surface hydrophobicity showed a trend of initially increasing and then decreasing. As the shear rate increased, the shear stress of the protein increased and the apparent viscosity decreased, indicating that TGase cross-linking promoted the generation of macromolecular polymers. In addition, the cross-linked protein exhibited a dense texture similar to that of the original protein, indicating the formation of a stable three-dimensional network structure. As the addition level of TGase increased from 4% to 12%, the protein network structure became increasingly dense. Moreover, an appropriate amount of TGase significantly improved the solubility, emulsifying properties, thermal stability, and oil-holding capacity of L. edodes protein. These results indicate that TGase cross-linking improves the physicochemical and processing properties of L. edodes protein to varying degrees.