Comprehensive NMR analysis of two kinds of post-fermented tea and their anti-glycation activities in vitro.
Comprehensive NMR analysis of two kinds of post-fermented tea and their anti-glycation activities in vitro.
复制标题
两种后发酵茶及其体外抗糖化活性的综合NMR分析。
DOI：
10.1016/j.foodchem.2018.11.028
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发表时间：
2019
期刊：
影响因子：
8.8
通讯作者：
Tanokura M.
中科院分区：
文献类型：
--
作者：
Zhang M;Otake K;Miyauchi Y;Yagi M;Yonei Y;Miyakawa T;Tanokura M.
后发酵茶（黑茶）是由酶失活的新鲜茶叶通过微生物发酵生产的。巴塔茶和阿瓦班茶是两种主要的黑茶，分别在有氧和厌氧条件下发酵。然而，它们的化学组成和功能在不同的后发酵过程中如何变化仍然不清楚。基于核磁共振（NMR）的分析表明，在有氧霉菌的后发酵过程中，巴塔茶中的（-）-表没食子儿茶素没食子酸酯（EGCG），（-）-表没食子儿茶素（EGC）和（-）-表儿茶素（EC）减少。与此相反，EGC和EC增加，并产生焦性没食子酸在阿瓦板茶与乳酸菌（LAB）后发酵。采用人血清白蛋白（HSA）体外抗糖基化活性测定系统，研究了两种黑茶的抗糖基化活性。巴塔茶的抗糖化活性降低，但在后发酵过程中，阿瓦班茶保留了抗糖化活性。结果表明，乳酸菌后发酵是提高茶叶中酚类物质含量的有效途径，邻苯三酚有助于提高茶叶的抗糖化活性。
Post-fermented tea (dark tea) is produced from enzyme-inactivated fresh tea leaves by microbial fermentation. Batabata tea and Awaban tea are two major dark teas fermented under aerobic and anaerobic conditions, respectively. However, how their chemical compositions and functionalities change during different post-fermentation processes remains unclear. Nuclear magnetic resonance (NMR)-based analyses showed that (−)-epigallocatechin gallate (EGCG), (−)-epigallocatechin (EGC) and (−)-epicatechin (EC) decreased in Batabata tea during post-fermentation with aerobic molds. In contrast, EGC and EC increased, and pyrogallol was produced in Awaban tea during post-fermentation with lactic acid bacteria (LAB). The anti-glycation activities of two dark teas were investigated using anin vitroassay system with human serum albumin (HSA). The anti-glycation activity decreased in Batabata tea, but it was retained in Awaban tea during post-fermentation. Our results showed that post-fermentation with LAB was an efficient way to enhance phenol content and that pyrogallol contributed to anti-glycation activity of Awaban tea.