【摘要】 通过研究不同渥堆时期(程度)普洱茶样中水解酶(纤维素酶、果胶酶和淀粉酶)和氧化酶(多酚氧化酶、谷胱甘肽过氧化物歧化酶、超氧化物歧化酶)活性的变化规律,以期探明普洱茶品质和功能形成机理。结果表明:渥堆过程,纤维素酶和淀粉酶的酶活性变化趋势一致,从毛茶原料(S0)到1翻样(S1)开始上升,在2翻样(S2)中达到最大,3翻样(S3)中有所下降,但仍高于S1的酶活性。果胶酶的酶活性呈现先上升后下降的趋势,从S0到S1急速上升,并且在S1达到最大值,S1到S3虽然下降仍然维持了比S0大的酶活性。渥堆过程,多酚氧化酶、谷胱甘肽过氧化物歧化酶、超氧化物歧化酶的活性均呈现从S0到S2上升,S2到S3缓慢下降的趋势。其中,多酚氧化酶与超氧化物歧化酶的变化趋势一致,从S0到S1时上升速度较慢,S1到S2时上升速度最快,在S2时达到最大,S2到S3虽然下降但是仍然维持了比S1时更大的活性。谷胱甘肽过氧化物歧化酶活性在S2时达到最大,S2到S3虽然下降,但是仍然保持了接近S2的活性。本研究表明,渥堆程度对普洱茶中的水解酶和氧化酶活性有重要影响,适度渥堆有利于普洱茶品质与功能的提高。更多还原

【Abstract】 In order to explore the mechanism for quality improvement of Pu’er tea,the change of enzymes including cellulase,pectinase,amylase,polyphenol oxidase(PPO),glutathione peroxidase(GSH-PX) and superoxide dismutase(SOD) was investigated during different stages of pile-fermentation process of Pu’er tea.During pile-fermentation process,cellulase and amylase exhibited a similar change trend that was a gradual increase from sun-dried green tea(S0) to 2nd-turned sample(S2),reaching a maximum value,and a subsequent decrease in 3rd-turned sample(S3),which maintained a higher enzyme activity than S0,although the decrease;pectinase exhibited a rapid increase trend from S0 to S1,and a following decline from S1 to S3.In addition,an increase from S0 to S2 and a subsequent reduction from S2 to S3 for the change trend of PPO,GSH-PX and SOD were observed.These investigations also suggested that pile-fermentation degree could provide a significant effect on activities of hydrolases and oxidases.Therefore,proper pile-fermentation process will be of benefit to the improvement of quality and functions of Pu’er tea.更多还原