Phenolic antioxidants identifled by ESI-MS from yerba mate (Ilex paraguariensis) and green tea (Camelia sinensis) extracts
Phenolic antioxidants identifled by ESI-MS from yerba mate (Ilex paraguariensis) and green tea (Camelia sinensis) extracts
复制标题
DOI：
10.3390/12030423
复制
发表时间：
2007-03-01
期刊：
影响因子：
4.6
通讯作者：
Eberlin, Marcos N.
中科院分区：
文献类型：
--
作者：
Bastos, Deborah H. Markowicz;Saldanha, Luciane A.;Eberlin, Marcos N.
绿色马黛茶（巴拉圭茶）和绿色茶（茶树）的水提取物是酚类抗氧化剂的良好来源，如文献中已经描述的。本研究的主题是从巴拉圭茶，绿色和烤，和从绿色茶的有机提取物。采用直接注入电喷雾插入质谱法（ESI-MS）对它们的酚类结构进行了表征，并通过DPPH法测定了它们的自由基清除活性。含有酚类抗氧化剂的有机提取物可能被食品工业用作天然抗氧化剂，取代目前使用的合成酚类添加剂。绿色马黛茶、炒马黛茶和绿色茶的乙醇提取物和水提取物对DPPH自由基具有较好的清除活性（> 89%）。从绿色和烤马黛茶醚提取物显示出较弱的清除活性，不同的行为观察到的绿色茶醚提取物。从绿色马黛茶水提物和乙醇提取物中鉴定出的主要酚类化合物为：咖啡酸、奎尼酸、咖啡酰葡萄糖、咖啡酰奎尼酸、阿魏酰奎尼酸、二咖啡酰奎尼酸和芦丁。在焙烧过程后，形成两个新的化合物：咖啡酰莽草酸和二咖啡酰莽草酸。结果表明，在较低的酚类物质浓度（3.80和2.83 mg/mL）下，马黛茶的乙醇提取物（烘烤的和绿色的）表现出较高的抗氧化活性，即使在很低的酚类物质浓度下，马黛茶的乙醚提取物（0.07 mg/mL）对DPPH的抑制率也超过90%。
Aqueous extracts of green yerba mate (flex paraguariensis) and green tea (Camellia sinensis) are good sources of phenolic antioxidants, as already described in the literature. The subject of this study were organic extracts from yerba mate, both green and roasted, and from green tea. Their phenolic profiles were characterized by direct infusion electrospray insertion mass spectrometry (ESI-MS) and their free radical scavenging activity was determined by the DPPH assay. Organic extracts containing phenolic antioxidants might be used as natural antioxidants by the food industry, replacing the synthetic phenolic additives used nowadays. Ethanolic and aqueous extracts from green yerba mate, roasted yerba mate and green tea showed excellent DPPH scavenging activity (> 89%). The ether extracts from green and roasted yerba mate displayed a weak scavenging activity, different from the behavior observed for the green tea ether extract. The main phenolic compounds identified in green yerba mate water and ethanolic extracts were: caffeic acid, quinic acid, caffeoyl glucose, caffeoylquinic acid, feruloylquinic acid, dicaffeoylquinic acid and rutin. After the roasting process two new compounds were formed: caffeoylshikimic acid and dicaffeoylshikimic acid. The ethanolic extracts from yerba mate, both roasted and green, with lower content of phenolic compounds (3.80 and 2.83 mg/mL) presented high antioxidant activity and even at very low phenolic concentrations, ether extract from GT (0.07 mg/mL) inhibited DPPH over 90%.