现代工艺六堡茶渥堆过程中茶汤色泽及主要滋味品质成分动态变化

Dynamic changes of tea soup color and main taste quality duringprocess of modern craft Liupao tea fermentation

通过对现代工艺六堡茶渥堆过程样品进行感官审评及电子舌、色差、主要生化成分测定,研究六堡茶渥堆过程中色泽及滋味成分的变化规律,并探讨了滋味属性的变化与滋味成分之间的相关性及滋味活度值(taste active value,TAV)。结果表明,现代工艺渥堆过程中,六堡茶酸味、苦味上升,涩味、鲜味及咸味下降,色差L值波动变化,a、b值逐渐升高,汤色由黄转变为橙红,游离氨基酸、黄酮、茶多酚、茶叶碱、儿茶素总量、氨基酸组分总量显著下降(P<0.05),可可碱、咖啡碱、没食子酸显著上升(P<0.05),水浸出物含量呈波动变化。游离氨基酸、黄酮、酯型儿茶素、DL-儿茶素(DL-catechin, DL-C)及部分氨基酸组分与酸味和苦味显著负相关,与涩味、鲜味及咸味显著正相关,咖啡碱与没食子酸则相反;茶多酚与涩味显著正相关。咖啡碱、可可碱、没食子酸、DL-C及酯型儿茶素对渥堆过程中六堡茶的滋味具显著贡献(TAV> 1),其中酯型儿茶素与没食子酸是六堡茶渥堆过程滋味品质形成的重要化合物,氨基酸组分对六堡茶滋味无显著贡献。

Through sensory evaluation,electronic tongue,color difference,and main biochemical components measurement of modern craft Liupao tea fermentation process samples,the change rule of color and flavor components in the Liupao tea fermentation process was studied,and the correlation between the change of flavor properties and flavor components as well as the taste active value(TAV)were discussed.Results showed that during the fermentation process of modern craft,the acidity and bitterness of Liupao tea increased,astringency,umami and saltiness decreased,color difference L value fluctuated,a and b values increased gradually,soup color changed from yellow to orange-red,and the total amount of free amino acids,flavonoids,tea polyphenols,tea base,catechin,and total amino acid components decreased significantly(P<0.05).Theobromine,caffeine and gallic acid were significantly increased(P<0.05),while the content of water extract fluctuated.Free amino acids,flavonoids,ester catechin,DL-catechin(DL-C),and some amino acid components were negatively correlated with sour and bitter taste,and positively correlated with astringency,umami,and saltiness,while caffeine and gallic acid were inversely correlated.There was a significant positive correlation between tea polyphenols and astringency.Theobromine,calfeine,gallic acid,DL-C,and ester catechin significantly contributed to the taste of Liupao tea in the fermentation process(TAV>1).Ester catechin and gallic acid were important compounds for the taste quality of Liupao tea during the fermentation process,while amino acid components had no significant contribution to the taste of Liupao tea.