多糖接枝对花生球蛋白功能特性的影响

Effect of Dextran Conjugation on the Conformational and Functional Properties of Arachin

摘要:

本文研究了花生球蛋白与葡聚糖能够在一定控温控湿的条件下进行干热反应，生成美拉德反应的多糖接枝产物。通过荧光光谱、圆二色谱、差示扫描量热法和紫外分光光度法等先进的检测分析手段对美拉德反应对接枝产物结构特性的影响进行表征，同时也阐述了接枝产物的结构变化与其功能特性改变之间的构效机理。研究结果表明花生球蛋白酸性亚基比碱性亚基更易与葡聚糖发生接枝反应。对花生球蛋白的预加热处理不能提高其与葡聚糖的反应速度。花生球蛋白与热处理花生球蛋白在与多糖接枝反应过程中，其三级结构皆变得更加紧凑，限制了蛋白与多糖的接枝反应速度与反应程度。未经热预处理的花生球蛋白与多糖的接枝产物具有很高的溶解性和乳化活性，在干热反应第14 d其溶解性和乳化活性指数达到实验条件下的最高值，分别为95%和149 m2/g。

Abstract:

Arachin can react with dextran to form conjugation products with high molecular weight. It was found that the acid subunits of arachin were easier to glycosylate with dextran than basic subunits. The heat-pretreatment of arachin could not increase the speed of Maillard reaction with dextran. Proteins in mixtures/conjugates might have a more compacted tertiary conformation than that in arachin, which might limit the extent of glycosylation. The conjugation with dextran could improve the solubility and emulsifying properties of arachin, while it was hard to improve the functional properties of arachin when pretreated by heat. Non-heat pretreatment arachin conjugated with polysaccharide had high solubility and emulsifying activity, and they could reach the highest values of 95% and 149 m2/g after dry heat of 14 days.