大豆分离蛋白与卵磷脂间相互作用对O/W型乳状液稳定性的影响

摘要

研究大豆分离蛋白与卵磷脂的复合比例及相互作用对乳化体系稳定性及功能性质的影响.结果显示:乳状液的乳化活性和粒径分布等性质受大豆分离蛋白与卵磷脂比例分配的影响较大.当大豆分离蛋白与卵磷脂间的质量比为10∶1时,复合体系的乳化活性较高(98.1 m2/g),同时乳液的体积平均直径D4,3最小(13.34 μm),乳液双峰分布程度较低.乳化稳定性和ξ-电位测试结果显示,复合体系中大豆分离蛋白与卵磷脂比例为1∶1或100∶1都不利于体系稳定,此时激光共聚焦显微镜观测乳液出现相分离和不规则非球形液滴.这说明大豆分离蛋白与卵磷脂作为复合乳化剂具有最适配比,在该比例下大豆分离蛋白与卵磷脂间的相互作用对食品级水包油(oil-in-water,O/W)乳状液的稳定性是有利的.%The purpose of this study was to explore the effect of the ratio and interaction between soybean protein isolate and lecithin on the stability and functional properties of emulsion systems containing them.The results showed that emulsion activity index and droplet size distribution were affected by the ratio between soybean protein isolate and lecithin.When the ratio was 10∶1,a higher emulsion activity index (98.1 m2/g) and the smallest D4.3 (volume average diameter,13.34 μrn) as well as a lower level of bimodal distribution were observed.A soybean protein isolate-to-lecithin ratio of 1∶1 or 100∶1 was not suitable due to poor emulsion stability,as demonstrated by the measurement of ξ-potential.Phase separation and large irregular non-spherical droplets were evident under confocal laser scanning microscopy.Therefore,there was an optimal soybean protein isolate-to-lecithin ratio that provided good stability of food-grade O/W emulsion.