用代表性植物甾醇对表没食子儿茶素没食子酸酯进行衍生化，提高 O/W 乳液的抗氧化活性和降低胆固醇的能力。

Enhancement of Antioxidant Activity in O/W Emulsion and Cholesterol-Reducing Capacity of Epigallocatechin by Derivatization with Representative Phytosterols.

机构信息

Department of Food Science and Nutrition, Fuli Institute of Food Science, Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment , Zhejiang University , 866 Yuhangtang Road , Hangzhou 310058 , China.

Qinghai Food Inspection and Testing Institute , 12 Beidajie , Xining 810000 , China.

出版信息

J Agric Food Chem. 2019 Nov 13;67(45):12461-12471. doi: 10.1021/acs.jafc.9b04382. Epub 2019 Oct 29.

DOI:10.1021/acs.jafc.9b04382

PMID:31613618

Abstract

In this study, derivatization of epigallocatechin (EGC) by representative phytosterols (stigmasterol and β-sitosterol) was performed employing Steglich esterification. The structural identity and purity of epigallocatechin β-sitosterol (ESi) and epigallocatechin stigmasterol (ESt) were confirmed by NMR, FT-IR, and HPLC-MS. Further evaluation of ESi and ESt revealed their extraordinary antioxidant activities in O/W emulsion. Two different radical sources in oil or aqueous phase were applied to explore the antioxidant behavior in O/W emulsion. The mechanism was further investigated by fluorescent microscopy and transmission electron microscopy (TEM). Furthermore, incorporation of EGC with stigmasterol and β-sitosterol notably enhanced the cholesterol-reducing activity. TEM studies suggested the hydrogen bonding of EGC strengthened the aggregation network of ESi and ESt in the bile salt micelle. The exceptional properties of ESi and ESt signified their intriguing utilization in the food industry.

摘要

在这项研究中，通过代表性的植物甾醇（豆甾醇和β-谷甾醇）对表没食子儿茶素（EGC）进行了衍生化，采用 Steglich 酯化反应。通过 NMR、FT-IR 和 HPLC-MS 确认了表没食子儿茶素 β-谷甾醇（ESi）和表没食子儿茶素豆甾醇（ESt）的结构同一性和纯度。进一步评估 ESi 和 ESt 发现它们在 O/W 乳液中具有非凡的抗氧化活性。在油相或水相中使用两种不同的自由基源来探索 O/W 乳液中的抗氧化行为。通过荧光显微镜和透射电子显微镜（TEM）进一步研究了该机制。此外，EGC 与豆甾醇和β-谷甾醇的结合显著提高了胆固醇降低活性。TEM 研究表明，EGC 的氢键增强了 ESi 和 ESt 在胆汁盐胶束中的聚集网络。ESi 和 ESt 的特殊性质表明它们在食品工业中有很大的应用潜力。