糖基化改性制备核桃分离蛋白-菊粉共轭物及其性质分析

Preparation of Glycosylated Walnut Protein Isolate-Inulin Conjugate and Analysis of Its Properties

为提高核桃蛋白溶解性,对核桃蛋白进行糖基化改性,通过单因素及响应面试验优化核桃分离蛋白-菊粉共轭物的制备工艺,测定核桃分离蛋白-菊粉共轭物的红外光谱、内源荧光光谱、溶解度、乳化特性等结构特性及功能性质。结果表明:当反应温度为89℃、反应时间为75 min、蛋白与糖质量比为1:2时,核桃分离蛋白-菊粉共轭物可达到最大溶解度83%,比核桃分离蛋白的溶解度提高了47%。傅里叶红外光谱、扫描电镜分析结果表明,核桃分离蛋白与菊粉通过共价键结合,结构由散落小颗粒状变为片状。功能性结果显示,与核桃分离蛋白相比,核桃分离蛋白-菊粉共轭物起泡性、泡沫稳定性分别提高了49%和23%,乳化性指数增加了17%。说明糖基化改性能够改善产物的结构及性质,本研究为核桃分离蛋白的加工利用提供新的方法途径,拓宽了核桃蛋白加工利用的领域。

To improve the solubility of the walnut protein,it was modified through glycosylation.The preparation process of the walnut protein isolate-inulin conjugate was optimized by single-factor and response surface tests.To determine the structural and functional properties of walnut isolated proteins-inulin conjugate,infrared spectra,endogenous fluorescence spectra,solubility and emulsification properties were studied.Results showed that when the reaction temperature was 89℃,the reaction time was 75 min,the mass ratio of protein to sugar was 1:2,and the walnut protein isolate-inulin conjugate could reach a maximum solubility of 83%,which was 47%higher than that of walnut isolated protein.Fourier infrared spectroscopy and fluorescence spectroscopy analyses showed that the walnut isolated protein and inulin were joined by covalent bonding,that their shape changed from scattered small granular particles into a sheet structure,and that their fluorescence intensity remarkably reduced.Compared with walnut isolate protein,the foamability and foam stability of walnut protein isolate-inulin conjugate increased by 49%and 23%,respectively,and the emulsification index increased by 17%.These results indicate that protein modification through glycosylation improved the structure and properties of the products.This paper would provide a new method for the processing and utilisation of walnut isolate protein and broadening the field of walnut protein processing and utilization.