通过添加外源氨基酸的渥堆发酵方法,探讨了外源氨基酸对普洱茶发酵过程中茶多酚、儿茶素和茶色素等的影响。结果表明:同对照组相比,实验组在发酵前期(二翻之前)堆温能达到较高水平,发酵过程中茶多酚和儿茶素有较大幅度减少;茶黄素和茶红素的含量一直处于较低水平,茶褐素有较快的积累,且在三翻时含量达到最大值,四翻时有所下降。回归分析表明:茶褐素同茶多酚、儿茶素和茶红素成极显著负相关,相关系数分别为-0.658、-0.921、-0.670,茶褐素与儿茶素和茶黄素之间有极显著的线性关系,回归方程为:Y=6.764-0.077 X2+1.992 X3。通过感官评定和茶汤色的光学特性分析,确定在添加外源氨基酸的条件下,发酵19d(三翻后1d)实验组产品即可达到陈年普洱茶汤色红亮,滋味醇和回甘的特点。

This article explored the effects of exogenous amino acids on the variation of tea polyphenols,tea catechins and tea pigments during fermentation process through the method of adding exogenous amino acids.The results demonstrated that the pile temperature would reach at higher levels at earlier stages compared with the control group.The decrease of tea polyphenols and tea catechins were greater than control group.The thearubigins and theaflavins of experimental groups remained at a low level.The theabrownins accumulated faster from the beginning,and reached the maximum at the third turning,then decreased a little at fourth turning during the fermentation process.According to the correlation analysis and regression analysis,theabrownins was significantly negatively correlated with tea polyphenols,tea catechins and thearubigins,and the correlation coefficients were-0.658,-0.921 and-0.670 respectively.It was also linearly correlated with tea catechins and theabrownins and the regression equation was Y=6.764-0.077 X2+ 1.992 X3.Through sensory evaluation and analysis of optical property,the products of experimental groups after 19 days(the day after third turning) of fermentation possessed the property of aged Pu-erh tea,red and glow liquor color,pure and mellow taste.