中文摘要：

为综合利用茶叶加工副产物茶叶梗,试验设计利用固态发酵得到的单宁酶处理茶梗,比较不同处理条件下的茶梗提取液中儿茶素组成的差异及还原力、DPPH和OH自由基清除率、胰α-淀粉酶和胰脂肪酶抑制活性变化,探讨单宁酶处理提高茶梗提取物中儿茶素含量和生物活性可行性。研究发现：在50℃条件下,利用2U/mL单宁酶溶液作用于茶梗粉末60min,茶梗提取液中酯型儿茶素（EGCG、ECG、GCG）基本被水解生成非酯型儿茶素（EGC、EC、GC）和没食子酸（GA）,从而减少单宁-蛋白质聚合物和茶乳的形成量;此外,经单宁酶处理的茶梗提取液抗氧化活性与对照比较明显增强,表现为OH和DPPH自由基清除率IC50分别降低了74%和26%;酶解茶梗提取液质量浓度为5000mg/L时,胰α-淀粉酶和胰脂肪酶抑制率分别提高了89%和107%。研究结果表明单宁酶可高效水解茶梗提取液中酯型儿茶素,提高茶梗提取液的抗氧化活性以及体外抑制胰α-淀粉酶和胰脂肪酶活性。

英文摘要：

Tea stalk, also known as tea stem, a residue obtained from the process of initial tea selection, is a very abundant and low-cost agricultural byproduct which is plentifully available in southern China, and its use has not been exploited and standardized. In this study, in order to use the agricultural byproduct, tea stalk, thoroughly, tea stalk infusion was prepared with the help of tannase preparation from Aspergillus niger JMU-TS528 by the solidstate fermentation of tea stalks. Then, the property and effectiveness of a tannase-aided treatment on the contents of catechins and bioactivity changes in tea stalk infusion were illustrated, including their antioxidant activity and inhibitory potential against pancreatic a-amylase and lipase in vitro. Results showed that, with the help of tannase （2 U/mL） treatment at 50℃ for 60 min, the contents of catechins in enzymatic hydrolysis tea stalk infusion changed a lot, much ester catechins （EGCG, GCG and ECG） were hydrolyzed into non-ester ones （EGC, GC and EC, respectively）, accompanied by the production of gallic acid. Compared to untreated tea stalk infusion which was extracted by boiling water, th total catechin in a tannase-treated analog increased by 11.5%, and ester catechins decreased by 94%, along with the increases of non-ester catechins and gallic acid （156% and 684%, respectively）. Meanwhile, the tannase-treated infusion had a relatively lower binding ability with protein and less tea cream formation, which were effective in improving the clarity and stability of tea stalk infusion. Furthermore, after being treated with tannase, the antioxidant activity of tea stalk infusion had a significant increase, as the tannase-treated tea stalk infusion had a greater OH and DPPH scavenging effects with their ICs0 decreased by 74.1% and 25.9%, respectively. In addition, assays of pancreatic a-amylase and lipase activities were used to evaluate the effects of tannase treatment on pancreatic enzymes inhibitory activities of tea stalk infusion. And whether