玉米糖肽的营养特性研究

Nutritional Properties of Corn Glycopeptide

以玉米醇溶蛋白源玉米肽为研究对象,采用D-氨基葡萄糖和转谷氨酰胺酶对其进行酶法糖基化修饰制备玉米糖肽,通过体外消化、大鼠氮代谢和生长实验评估了玉米糖肽的营养特性。结果表明:玉米糖肽的肽质量分数为78.31%,分子质量分布在>6 500 u (32.37%)、6 500~4 259 u (3.32%)、4 259~427 u (41.79%)和<427 u (22.48%)范围内;真消化率和净蛋白利用率分别为(98.54±0.52)%和(95.01±1.61)%,与酪蛋白相比差异不显著(P>0.05);校正蛋白质功效比值和相对净蛋白质比分别为1.60和71.79,分别是玉米肽的1.70倍和1.35倍,说明玉米糖肽具有促进动物生长发育的能力,且糖基化修饰在一定程度上改善了玉米肽的营养品质。

In the present work, corn peptide from zein was modified by D-glucosamine and transglutaminase to produce corn glycopeptide, and then, nutritional properties of corn glycopeptide were assessed by in vitro digestion, nitrogen metabolism and growth experiments in rat. The results indicated that the peptide content of corn glycopeptide was 78.31%;the molecular distribution was<427 u(22.48%), 427~4 259 u(41.79%), 4 259~6 500 u(3.32%), and >6 500 u(32.37%);the true digestibility and net protein utilization rate of corn glycopeptide were(98.54±0.52)% and(95.01±1.61)%, respectively, not significantly different from that of casein(P>0.05);the corrected protein efficacy ratio and relative net protein ratio of corn glycopeptide were 1.60 and 71.79, respectively, 1.70 and 1.35-fold higher than those of zein peptide, indicating that corn glycopeptide had the effect of promoting animal growth and development, and the nutritional quality of zein peptide was improved by glycosylation modification to a certain extent.