数控与传统发酵普洱茶抗氧化活性与化学成分的比较

摘要

Two fermentations of Pu-erh tea were developed by numerical control and traditional methods,respectively.The chemical compounds of tea leaves were detected by high-performance liquid chromatography (HPLC) and spectrophotometric methods.The quality was compared by electronic nose test and sensory evaluation.The in vitro antioxidant activity of final fermented tea leaves was also determined and compared.The results showed that the contents of water extraction,tea polyphenols,theabrownin (TB),theaflavin (TF),and catechins were decreased;the contents of thearubigin (TR),caffeine and soluble sugar were increased.However the speed of chemical change in numerical control fermentation was faster than that in traditional fermentation;and the "pile aroma" was lower than that in traditional fermentation.The total antioxidant and superoxide anion radical scavenging activity of final fermented tea leaves in numerical control fermentation were lower than that in traditional fermentation;and hydrogen donating scavenging capacity of final fermented tea leaves in numerical control fermentation was higher than that in traditional fermentation.The DPPH scavenging capacity had no significant difference.In brief,the chemical change rule in numerical control and traditional fermentation was same;and compared to traditional fermentation,the fermentation speed was faster and the flavor was better in numerical control fermentation.%分别应用数控与传统方法进行普洱茶发酵,应用紫外分光光度法和高效液相色谱法测定发酵样品的化学成分,结合电子鼻和感官审评比较发酵样品品质特征,并测定比较出堆样品的体外抗氧化活性.结果表明,2种发酵过程水浸出物、茶多酚、茶黄素、茶红素、儿茶素含量降低,茶褐素、咖啡碱含量增加,但数控发酵过程中,化学成分含量变化速度更快,且“堆味”更少.数控发酵出堆样的总抗氧化活性、超氧阴离子清除活性能力低于传统发酵,羟自由基清除活性高于传统发酵,而DPPH自由基清除活性二者之间没有显著性差异.总之,数控与传统发酵茶叶化学物质变化规律相同,但发酵速度更快,香气更好.