霜降前后白茶主要化学成分及生物活性分析

Analysis of Main Chemical Components and Bioactivities of Pre-frost and Post-frostWhite Tea

采用山东省日照市黄山群体种茶树霜降前后一芽二叶鲜叶原料,按照白茶加工工艺制备白茶样品,研究分析了霜降前后白茶样品主要化学成分的差异以及体外生物活性情况。化学成分分析表明,“霜前”“霜后”白茶样品的水浸出物含量、可溶性碳水化合物含量、茶多酚含量、总黄酮含量以及儿茶素含量等存在明显差异;广靶代谢组学分析表明,“霜前”“霜后”两组白茶样品中存在差异化合物有10大类99种,主要包括脂质(16种)、糖及醇类(15种)、黄酮类(13种)、生物碱类(12种)、氨基酸及其衍生物(12种)、核苷酸及其衍生物(9种)、有机酸类(8种)、酚酸类(7种)、木脂素和香豆素(4种),以及鞣质(3种);相较于“霜前”白茶,“霜后”白茶中有49种差异化合物呈上调趋势、46种差异化合物呈下调趋势;活性分析结果表明,“霜前”白茶样品的体外抗氧化活性和抑制α-淀粉酶活性显著高于“霜后”白茶样品,“霜后”白茶样品的胆酸盐结合活性高于“霜前”白茶样品;两种白茶样品对NO抑制率水平无显著性差异。

The raw materials of one bud and two leaves of'Huangshan tea population'in Rizhao City,Shandong Province were used to prepare white tea samples after frost stress according to the processing technology of white tea.Compared with the"pre-frost"white tea samples,the main chemical components and differences in their biological activities in vitro were studied and analyzed.The results indicate that the contents of water extract,water soluble carbohydrate,tea polyphenols,total flavonoids and catechins of"pre-frost"and"post-frost"white tea were significantly different.The wide target metabolomics analysis shows that,there were 99 kinds of differential components in 10 categories in the"pre-frost"and"post-frost"white tea samples,including free fatty lipids(16 kinds),saccharides and alcohols(15 kinds),flavonoids(13 kinds),alkaloids(12 kinds),amino acids and their derivatives(12 kinds),nucleotides and their derivatives(9 kinds),organic acids(9 kinds),phenolic acids(7 kinds),lignans and coumarins(4 kinds)and tannins(3 kinds).Among these compounds,49 showed the upward trend and 46 showed a downward trend.The results show that the level of antioxidation andα-amylase inhibition in the"pre-frost"white tea were significantly higher than that of"post-frost"white tea.The bile acid salt-binding activity of"post-frost"white tea was significantly higher than that of"pre-frost"white tea,and there was no significant difference in NO inhibition rate between the two groups of white tea samples.