聚甘油脂肪酸酯结构对姜黄素纳米乳液稳定性及其功能特性的影响

使用聚甘油脂肪酸酯（polyglycerol fatty acid esters，PGFEs）制备姜黄素纳米乳液，并探究PGFEs的脂肪链长（C10～C18）对姜黄素纳米乳液的乳液特性、贮存稳定性、抗氧化活性及抗菌活性的影响。结果表明：PGFEs脂肪链长的增加会使乳液粒径增大、Zeta电位变低，但不影响姜黄素的包封效率。PGFEs纳米乳液在4?℃和30?℃时具有良好的物理化学稳定性（28?d），但在50?℃时粒径随时间延长剧烈增大且伴随姜黄素的快速降解。相比其他PGFEs乳液，聚甘油癸酸酯（polyglycerol capric acid esters，PGC）乳液表现出较强的热稳定性。自由基清除实验显示，中链PGFEs乳液能显著提高姜黄素的自由基清除活性（P＜0.05）。最小抑菌浓度测定结果表明，中链PGFEs乳液对金黄色葡萄球菌和大肠杆菌具有抗菌活性，且PGC与姜黄素存在协同抗菌效应。

Impact of the Structure of Polyglycerol Fatty Acid Esters on the Stability and Functional Performance of Curcumin-Loaded Nanoemulsions

The effects of the aliphatic chain length of polyglycerol fatty acid esters (PGFEs) on physicochemical characteristics, storage stability, antioxidant activity and antimicrobial activity of curcumin-loaded nanoemulsions were evaluated. It turned out that longer aliphatic chain of PGFEs increased the droplet size and decreased the zeta potential of nanoemulsions, but had little impact on the encapsulation efficiency of curcumin. Moreover, PGFE-stabilized nanoemulsions were stable for 28 days at 4 or 30 ℃, while the particle size of nanoemulsions drastically increased over time at 50 ℃, accompanied by rapid degradation of curcumin. Compared to other PGFEs, nanoemulsions formulated with polyglycerol capric acid esters (PGC) displayed greater thermal stability. Nanoemulsions stabilized by medium-chain PGFEs significantly (P < 0.05) enhanced the radical-scavenging activity of curcumin, and showed antimicrobial activity against Staphylococcus aureus and Escherichia coli. There was a synergistic inhibitory effect between PGFEs and curcumin.