The Effect of Polyphenol Oxidase on the Pile-fermentation Process and Quality of Pu-erh Tea
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.
国家科技期刊平台
NSTL
万方数据
维普
