乳清分离蛋白-葡聚糖接枝物的乳化性能研究

A294和褐变程度的变化证实乳清分离蛋白与葡聚糖在干热处理条件下确实发生了以美拉德反应为机理的接枝反应。由于亲水性葡聚糖的共价接入,导致接枝物在O/W乳液中能够快速且更为紧密地吸附在油-水界面上,在油滴表面形成厚的界面膜,从而提高了乳清分离蛋白的乳化性能。在pH3~10范围内,接枝产物G150的乳化活性明显优于原蛋白;对接枝物样品溶液在90°C保温处理10min后,可以进一步提高其乳化活性;高盐体系中接枝产物G150的乳化活性并未发生明显的下降。

A Study on Emulsification Properties of Whey Protein Isolate-Dextran Conjugate

Significant changes in A294and browning intensity showed that whey protein isolate（WPI）-dextran conjugate was successfully formed using dry-heating treatment via Maillard Reaction. The emulsification properties of WPI were significantly enhanced by the covalent attachment of hydrophilic dextran. In the glycoprotein-stabilized emulsions,hydrophobic protein moiety firmly attached to the oil droplet surface and the bulky hydrophilic part of covalently linked polysaccharide highly oriented to the water phase,which was supposed to provide a steric stabilizing layer to inhibit the coalescence of the oil droplets. Obviously,the conjugate G150 had better emulsifying capabilities than initial WPI at the pH range of 3 to 10. The emulsifying capability could be enhanced when the G150 solution was heated at 90°C for 10min.Moreover,there was no decrease in the emulsifying capability of G150 solution when high salinity was added.