[关键词]
[摘要]
本论文以两类植物球蛋白:豌豆分离蛋白(PPI)和大豆分离蛋白(SPI)为材料制备荷载姜黄素蛋白纳米复合物,并探究荷载前后蛋白所制备乳液的物理和氧化稳定性差异。结果表明:PPI和SPI在pH 3.0和pH 7.0下荷载前后蛋白纳米颗粒粒径没有明显变化。pH 7.0时两蛋白姜黄素荷载量均高于pH 3.0,各pH下SPI荷载量要高于PPI。表面疏水性的显著降低与荧光淬灭现象发生表明形成两种蛋白纳米复合物的主要作用力为疏水相互作用,同时在两pH下,PPI比SPI荧光蓝移趋势更明显且有效淬灭常数也更大,即更易形成复合物。与原蛋白相比,荷载后各蛋白颗粒所制备乳液乳化活性有少许降低,同时pH 3.0时各蛋白颗粒乳化活性要高于pH 7.0。各乳液生成初级氧化产物脂质氢过氧化物浓度的变化趋势与生成次级氧化产物TBARS相类似,均为荷载姜黄素后各乳液氧化水平加速,同时pH 3.0时各类型乳液油滴氧化程度均高于pH 7.0。
[Key word]
[Abstract]
Curcumin-loaded nanocomplexes were fabricated from two kinds of widely used plant globulins, pea protein isolate (PPI) and soy protein isolate (SPI). The impact of these nanocomplexes on physical and oxidative stability of corresponding nanoparticles stabilized oil-in-water emulsions was investigated. The results showed that there were no significant changes in particle size after complexation at pH 3.0 and pH 7.0. The loading amount (LA) of SPI was higher than that of PPI at each pH value, while the LA at pH 7.0 was higher than that at pH 3.0 for each protein. The changes in fluorescence quenching profiles and a notable decrease in surface hydrophobicity indicated that the main interaction between globulins and curcumin was hydrophobic forces, where PPI was more favorable to form nanocomplexes as compared to SPI. Complexation process slightly weakened the emulsifying ability of PPI and SPI particles. PPI and SPI exhibited better emulsifying ability at pH 3.0 rather than at pH 7.0. A similar trend of variation was observed for the yield of oxidative products from lipids: lipid hydroperoxides and thiobarbituric acid reactive substances. Complexation of PPI and SPI nanoparticles with curcumin accelerated the oxidation rate of globulin particles stabilized in oil droplets. The oxidation degree of emulsion droplets at pH 3.0 was much higher than that at pH 7.0. This study provides useful information regarding the regulatory properties of emulsion-based functional foods by changing stabilizer type.
[中图分类号]
[基金项目]
国家自然科学基金面上项目(31171632,31471695)