大豆分离蛋白-葡聚糖糖基化产物作为乳化剂和活性物质载体的性能分析

Emulsifier and Carrier Performance of Soy Protein Isolate-Dextran Conjugates

研究大豆分离蛋白(soy protein isolate,SPI)-葡聚糖共价接枝物的制备及其乳化性质和作为姜黄素载体的性能。在95℃的"大分子拥挤"体系条件下,2种大分子通过美拉德反应进行共价接枝。根据糖基化产物在SPI等电点附近(p H 4.5)和中性(p H 6.5)条件下的溶解性将其分成2个组分,分别为MC45和MC65,并对其性能表征分析。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳和分子质量测定分析显示,反应后生成大分子质量的接枝物。MC45制备的乳液在酸性环境中的粒度低于MC65,其平均粒径约为10μm,并且受离子浓度和温度的影响较小。与天然蛋白、SPI-葡聚糖混合物及MC45相比,荷载量、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率分析表明MC65组分具有更好的姜黄素运载性能,MC65组分制备的姜黄素纳米颗粒荷载量为30.21μg/mg,DPPH自由基清除率为18.33%,其粒径最大。

Soy protein isolate(SPI)-dextran conjugates(CON)were prepared through Maillard reaction in solution under macromolecular crowding environment,then fractionated by their solubility at pH 4.5(MC45)and pH 6.5(MC65),and characterized.SDS-PAGE and molecular weight distribution of the conjugates showed typical patterns of conjugate formation and different characteristics between MC45 and MC65.The effects of pH,heating temperature and the addition of NaCl on the properties of emulsions stabilized with SPI-dextran conjugates were examined using a light-scatter particle size analyzer and a Zeta-potential analyzer.Results showed that in an acidic environment the average droplet size(d43)of the emulsion with MC45 was 10μm,lower than that of the emulsion with MC65,and was little affected by ion concentration and temperature.Compared with native protein,SPI-dextran mixture and MC45,MC65 had better curcumin loading capacity with respect to loading amount(30.21μg/mg)and 1,1-diphenyl-2-picrylhydrazyl(DPPH)radical scavenging capacity(18.33%DPPH scavenging)and resulted in larger particle size.