多酚氧化酶对普洱茶渥堆发酵过程中品质变化的影响

The Effect of Polyphenol Oxidase on the Pile-fermentation Process and Quality of Pu-erh Tea

摘要:

本文探讨了添加不同浓度多酚氧化酶对渥堆发酵过程中普洱茶理化指标和感官品质的影响。实验结果表明：经不同浓度多酚氧化酶处理后的普洱茶，其部分品质成分在渥堆发酵过程中的变化差异显著（p<0.01），与对照组相比，实验组的渥堆平均温度相对较高，茶多酚、儿茶素指标变化速度加快，且与多酚氧化酶的添加量呈负相关；茶黄素发酵前期生成速度加快，后期转化速度提高；茶褐素有较快积累。加入多酚氧化酶的普洱茶发酵18 d后，在外形、汤色、滋味、香气、叶底等感官品质上基本具有熟茶的品质，其中1.6 U/g、3.2 U/g多酚氧化酶组可达到陈年普洱汤色红浓明亮，滋味醇厚回甘，香气浓郁的品质特点。本研究为缩短发酵周期，改善普洱茶品质提供新的思路和方法。

Abstract:

The change in the physical and chemical properties and sensory quality of Pu-erh tea was investigated during the pile-fermentation process, facilitated by the addition of different concentrations of polyphenol oxidase (PPO). The results showed significant changes in some quality components (p < 0.01) during the pile-fermentation process after treatment with PPO. The average pile-fermentation temperature was observed to be higher in the treatment group, compared to the control group. In addition, the change rates in polyphenols and catechins accelerated in the treatment group, and were negatively correlated with PPO concentration. Theaflavin accumulation was faster during the early stage of pile-fermentation, and the transformation occurring rapidly during the late stage of pile-fermentation. On the other hand, the accumulation of theabrownins was observed to be faster during the pile-fermentation process. Pile-fermentation for 18 days with added PPO conferred good organoleptic properties (associated with sensory qualities) to the Pu-erh tea, including tea stripe, color of tea soup, taste and aroma, as well as tea leaf. 1.6 U/g and 3.2 U/g PPO groups were observed to attain properties of aged Pu-erh tea, with a red and glow liquor color, pure and mellow taste, and full-bodied aroma. This study provides new ideas and methods to reduce the pile-fermentation period and improve the quality of Pu-erh tea.