不同潮水量下普洱茶渥堆过程中微生物及酶活变化研究

运用实验室规模模拟渥堆,研究不同潮水量(30%、35%、40%、45%)下普洱茶渥堆过程中微生物及酶活的变化。结果表明:渥堆过程中,初期霉菌大量生长,呈现优势菌种,后期堆温下降,酵母、细菌开始大量生长。35%潮水量下多酚氧化酶活性显著高于其它组,且堆温对多酚氧化酶活性影响不大,渥堆过程中微生物不分泌过氧化物酶。45%潮水量下蛋白酶活后期低于原料样,相比其他组显著偏低,说明潮水量过高、堆温降低会在一定程度上抑制蛋白酶酶活。淀粉酶酶活随潮水量增加显著增强,但潮水量40%与45%差异不明显。40%、45%潮水组茶胚果胶酶、纤维素酶酶活高于30%、35%。因此,选择合适的潮水量有利于普洱茶品质与功能的提高。

Study on change of microbes and enzyme activities of Pu-erh tea during pile-fermentation process with various water contents

The change of microbes and enzyme activities was investigated during different stages of pile-fermentation process of Pu-erh tea with various water contents(30%,35%,40%,45%)in laboratory-scale.During pile-fermentation process,mould was dominant strain growth in large number at the beginning,then yeast and bacteria increased later while pile temperature went down.PPO of 35%group had significantly higher enzyme activity than others,and pile temperature had little effect on PPO.There was no POD secreted by microorganisms during pile-fermentation process.Protease of 45% group in later phase of fermentation had lower enzyme activity than raw material,and was significantly lower than other groups.It indicated that protease could be inhibited by high water content and low temperature.Amylase activity was significantly enhanced with water content increased,but there was no significant difference between 40% and 45% groups.Pectinase and cellulase of 40%,45% group had higher enzyme activity than 30%,35% group.Therefore,proper water content will be benefit to the improvement of quality and functions of Pu-erh tea.