蛋白质谷氨酰胺酶对米谷蛋白功能性质的影响

Effects of Glutaminase on the Functional Properties of Rice Glutelin

研究蛋白质谷氨酰胺酶对米谷蛋白功能性质的影响,测定米谷蛋白及其脱酰胺样品的溶解度、乳化、起泡、黏度、持水持油力等功能性质。结果表明,谷氨酰胺酶法脱酰胺的米谷蛋白其功能性质均有提高,在中性溶液中溶解度显著增加(达到96.99%);酶解时间1～12h的范围内,改性蛋白在中性条件下的乳化性能最好,酶解时间1～5h的范围内,强酸性条件下的乳化稳定性得到显著改善,并呈现出最佳的起泡性能,而起泡稳定性和黏度则随着反应时间的增加均逐渐降低;此外,改性蛋白与未改性蛋白比较,持水性提高1.75～2.03倍,持油性提高1.58～1.94倍。

To probe into the effect of glutaminase modification on the functional properties of rice glutelin,rice glutelin was prepared in our laboratory and enzymatically modified with glutaminase,and rice glutelin and its modification products at different treatment time points were analyzed for their solubility,emulsifying properties,foaming properties,viscosity,waterbinding capacity,oil-binding capacity and so on.The results showed that glutaminase modification could improve various functional properties of rice glutelin.After glutaminase modification,the solubility of rice glutelin was obviously increased （up to 96.99%）.The modification products of rice glutelin in the hydrolysis time range of 1 to 12 h had the best emulsifying properties,and after hydrolysis for 1 to 5 h,the strong acid resistance of rice glutelin was remarkably improved and an optimal foaming capacity was observed.However,its foam stability and viscosity both gradually decreased with increasing reaction time.Furthermore,glutaminase modification resulted in a 1.75 to 2.03-fold increase in water-binding capacity and a 1.58 to 1.94fold increase in oil-binding capacity.