Effect of transglutaminase treatment on the functional properties of native and chymotrypsin-digested soy protein

摘要

Native and chymotrypsin-digested soy protein were po1ymerizcd by transglutalninilse (TGase). SDS-PAGE pattern of the polymerized proteins showed that TGasc treatment resulted in proteins of higher n1oleculilr mass above the stacking gel. The free amino groups of the polymerized proteins were greatly reduced. The solubility of the protein polymer wills greatly improved at pH 2 and pH 8-l2 whereas. at pH 4 and 6, it was least soluble. The solubility of the digest polymer was significantly improved at all pH levels, except pH 4. The protein polymer started to coagulate when the heating temperature exceeded 50 deg C. The digest polymer, on the other hand, resisted heat-induced aggregation up to 60 deg C. therealier. its solub1lity declined sligl1tly. The emu1sifying and foaming properties of the digest polymer were greatly improved compared to the protein po1ymer. The protein po1ymer was observed to form a harder gel than the digest polymer.