Analysis of α-amylase Inhibitor Content Change in Pu-erh Tea During Pile-fermentation Process

The study was to investigate the changes of α-amylase inhibitor content in Pu-erh tea during pile-fermentation process.Pu-erh tea samples from two regions of Shuangjiang County and Jinggu Dai and Yi Autonomous County of Yunnan Province at various fermentation stages were used as experimental materials to investigate the effect of different fermentation stages on the inhibitory effect to α-amylase;and the change law of the inhibitory effect of α-amylase inhibitor during processing was meanwhile studied by determining the contents of tea polyphenol and amino acid.The results showed that crude material of Pu-erh tea presented strong inhibitory effect to α-amylase;this inhibitory effect assumed a decreasing trend to the minimum at the middle stage of fermentation,whereafter it increased to some extent.Made tea also showed a strong inhibitory effect to α-amylase.During whole processing period,contents of tea polyphenol and amino acid generally assumed a remarkably decreasing trend.Our results provided references for further isolating α-amylase inhibitor from Pu-erh tea and discussing the mechanism of its health care function.