渥堆发酵过程中木糖添加量对普洱茶品质的影响

以实验室环境模拟普洱茶发酵过程，研究木糖添加量（0.2%～0.8%）对普洱茶渥堆发酵过程中微生物、多酚氧化酶酶活、理化性质和感官品质的影响。结果表明：与空白组相比，添加0.8%、0.6%木糖的渥堆平均温度相对较高；发酵前期的霉菌总数和多酚氧化酶活最大值与木糖添加量正相关；茶多酚、儿茶素指标变化速度加快，且与木糖添加量正相关；而木糖添加量对茶黄素变化呈显著负相关，相关系数为－0.492。与空白组24 d发酵周期相比，添加0.8%木糖组的发酵时间可以缩短到18～19 d，0.6%木糖组可以缩短到19～21 d，0.4%可缩短到21～23 d。添加木糖各组茶汤滋味比空白组更甘甜，香气更浓郁，优于空白组。

Effects of Addition of Different Contents of Xylose on the Quality of Pu-erh Tea during Pile Fermentation

The effect of different levels of xylose addition (0.2%–0.8%) on microbes, polyphenol oxidase activity, physical
and chemical properties and organoleptic quality of Pu-erh tea during the pile-fermentation process was investigated in a
simulated laboratory environment. The results showed that the average pile-fermentation temperature was significantly higher
upon xylose addition at 0.8% and 0.6% compared with the control. Mould quantity at the early stage of fermentation and the
maximum polyphenol oxidase activity were positively correlated with xylose concentration. The changes of polyphenols and
catechins were also accelerated when compared with that of the control and positively correlated with xylose concentration.
However, theaflavin was significantly negatively correlated with xylose concentration with a correlation coefficient of
－0.492. By adding 0.8%, 0.6% and 0.4% xylose the fermentation time could be shortened to 18–19 d, 19–21 d and 21–23 d,
respectively, compared with 24 d for the control. The tea fermented with the addition of xylose was much sweeter and had a
stronger aroma than the control.