本文通过胃肠道消化，研究了六堡毛茶、成品茶中主要酚类物质在的含量、抗氧化能力上的变化，并以成品茶乙酸乙酯相作为对照。说明六堡茶制作过程中成分的差异导致抗氧化活性上的变化。消化前，六堡毛茶中GA含量相对较高；六堡成品茶中咖啡碱含量相对较高。消化后，主要的酚类物质（GA、原儿茶酸、原花青素、EGCG、GCG和ECG）均有80~90%的下降。抗氧化性随之降低。GA、原花青素、EGCG、ECG和GCG在毛茶水提物中与抗氧化活性呈显著相关性，在六堡茶水提物中原花青素（0.994）、EGCG（0.997）呈极其显著相关。六堡毛茶和六堡成品茶的酚类含量分别为28.41%和17.87%，对应的抗氧化能力为16.73 mg/L和15.37 mg/L。消化以后，多酚含量分别下降了68.85%和69.72%，对应的抗氧化活性下降了88%和82%。六堡成品茶抗氧化功能下降比例更低，保持能力更强。最可能影响的抗氧化活性的物质为GA、原花青素、EGCG和ECG。

Changes in the concentration of the main phenolic compounds and their antioxidant capacities in raw and aged Liubao tea during gastrointestinal digestion were evaluated in this study. Ethyl acetate, an extract of the aged Liubao tea, was used as a control. The results indicated that differences in the composition of Liubao tea during the production process led to changes in antioxidant activity. Before digestion, the amount of gallic acid (GA) in raw tea was relatively high, whereas high caffeine content was observed in aged tea. After digestion, the concentrations of the main phenolic compounds (GA, protocatechuic acid, procyanidins, epigallocatechin 3-gallate (EGCG), gallocatechin 3-gallate (GCG), and epicatechin 3-gallate (ECG) decreased by 80~90%, and their antioxidant activities also decreased accordingly. The concentrations of GA, procyanidins, EGCG, ECG, and GCG in the aqueous extract of Liubao tea significantly correlated with their antioxidant activity. In addition, the amounts of procyanidins (0.994) and EGCG (0.997) showed a significant correlation. The percentage of phenols in raw and aged tea were 28.41% and 17.87%, respectively, and their corresponding antioxidative capacities were 16.73 mg/L and 15.37 mg/L, respectively. After digestion, the amount of polyphenols decreased by 68.85% and 69.72%, respectively, and the corresponding antioxidant activities decreased by 88% and 82%, respectively. The aged tea demonstrated better antioxidant activity and a higher ability to maintain antioxidant activity. The substances that most likely affected the antioxidant activities were GA, procyanidins, EGCG, and ECG.

国家科学自然基金项目（31660493）；广西科学科技发展项目（159832-05）；广西八桂学者团队项目资助