渥堆过程六堡茶品质成分分析及茶褐素抗氧化功能研究

试验以广西梧州市苍梧县群体种毛茶为原料,利用现代化冷水渥堆工艺制作的、不同发酵阶段的茶样为研究对象,对其外形、汤色、香气、滋味、叶底等感官品质与茶多酚、茶色素、游离氨基酸、可溶性糖、咖啡碱、黄酮类物质等化学成分变化规律及茶褐素理化成分和抗氧化活性进行比较研究.结果表明:渥堆过程中,水浸出物的百分比、茶多酚、茶红素、游离...

Quality Component Analysis and Antioxidant Function of Theabrownins from Liupao Tea during Fermentation Process

This study investigated the changes of the sensory qualities of appearance, color, aroma, taste, leaf bottom and the chemical components of tea polyphenols, free amino acids, soluble sugar, caffeine, flavonoids, theabrownin (TB), theaflavin (TF) and thearubigin (TR) using the Liupao tea during processing and was produced by group species Zhongcha Tea Factory in Cangwu County, Wuzhou City, Guangxi, China. In addition, the chemical composition, and the antioxidant of the theabrownin (TB) that extracted from the Liupao tea were investigated. The results showed that the contents of water extract, tea polyphenols, thearubigin (TR), free amino acids and flavonoids were significantly decreased during the fermentation process (P<0.05), while the content of TB was significantly increased (P<0.05). The taste of tea had changed from strong and irritant to mellow and smooth. With the increasing of fermentation days, the contents of total sugar, total protein and total phenol in theabrownins all showed an increasing trend. In vitro antioxidant assays showed that the half maximal inhibitory concentration (IC₅₀) of each group were 10.09 μg/mL (V_C), 69.33 μg/mL (20 d), 49.95 μg/mL (40 d) and 51.85 μg/mL (60 d). The scavenging activity of DPPH free radical was as follows: V_C>40 d>60 d>20 d. The results of this study would provide a theoretical basis for the production and processing of Liupao tea.