【摘要】 本研究利用转谷氨酰胺酶(TGase)的催化特性,以及氨基糖和壳寡糖的伯胺活性,通过酶法的糖基化途径分别将氨基葡萄糖、壳寡糖导入到乳清蛋白分子中,达到改善乳清蛋白界面性质的目的。修饰反应可以提高乳清蛋白的持水性、吸油性和流变学性质,但降低它的乳化性质。氨基葡萄糖和壳寡糖的修饰产物,持水性分别提高24.25%和53.00%,吸油性分别提高1.50倍和2.85倍,分散液的表观黏度显著提高,动态模量增加且弹性模量始终高于黏性模量。但是,两种糖修饰产物的乳化活性分别降低36.00%和45.89%,乳化稳定性则分别降低22.14%和30.78%。由此结论,在转谷氨酰胺酶的催化下,利用氨基葡萄糖、壳寡糖的乳清蛋白糖基化修饰,可以改善它的某些功能性质。更多还原

【Abstract】 The catalytic specificities of transglutaminase(TGase, EC 2.3.2.13) and the reactive primary amine of glucosamine and oligochitosan, it is possible in a technologically feasible and‘food-safe’way to prepare protein-saccharide conjugates with improved the functional properties via the catalysis of TGase. The modified whey protein(glucosamine, oligochitiosan) exhibited about 24.25%and 53.00% higher water binding capacity respectively and about 1.5 and 2.85-folds oil binding capacity respectively. However, the emulsifying of modified products was decreased, including emulsifying activity index(EAI) and Emulsion stability index(ESI). In the modified whey protein(glucosamine,oligochitiosan), EAI has decerased 36.00% and 45.89% respectively; ESI has reduced 22.14% and 30.78% respectively. In rheological properties, the data revealed that apparent viscosity of the dispersion of modified whey protein was significantly increased and presented the shear thinning characteristics. Meanwhile, the dynamic modulus of modification was increased and elastic modulus is always higher than the viscous modulus. In conclusion, glucosamine or oligosaccharide glycosylated modification by transglutaminase, could improve some functional properties. Therefore, this technique is a potential protein modification technique.更多还原