不同花色种类白茶的抗氧化活性及其主要品质化学成分分析

目的：分析不同花色种类白茶（白毫银针、白牡丹和寿眉）茶汤的抗氧化活性、茶汤中的主要品质化学成分以及二者的相关性。方法：采用铁还原抗氧化能力、清除1,1-二苯基-2-三硝基苯肼自由基活性、清除2,2’-联氮基-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐自由基活性以及清除超氧阴离子自由基活性4 种不同的分析方法，检测分析3 种不同花色种类白茶茶汤的抗氧化活性；同时测定不同花色种类白茶茶汤中的主要品质化学成分的含量，并在此基础上进行相关性分析。结果：3 种不同花色种类的白茶相比，白毫银针的抗氧化活性最强，显著高于白牡丹和寿眉的抗氧化活性（P＜0.05）；而白牡丹和寿眉的抗氧化活性之间不存在显著性差异（P＞0.05）。游离氨基酸、莽草酸、表没食子儿茶素没食子酸酯等化学成分的含量在3 种不同花色种类的白茶茶汤中存在显著差异（P＜0.05）。相关性分析表明，白茶茶汤的抗氧化活性主要与儿茶素类化合物总量、总黄酮含量以及有机酸总量具有较大的相关性，其中与表没食子儿茶素没食子酸酯和奎尼酸的相关性最强。结论：不同花色种类白茶的抗氧化能力及其品质化学成分的含量水平存在较大差异。

Antioxidant Activities and Major Chemical Components in Tea Infusions of Different Kinds of White Tea

In this study, we examined and correlated the antioxidant activities and main quality components of tea infusions
of three different kinds of white tea, i.e., Baihaoyinzhen (BHYZ), Baimudan (BMD) and Shoumei (SM). The antioxidant
activities were tested using 1,1-dipheny1-2-picryl hydrazyl (DPPH) radical scavenging, 2,2’-azinobis-(3-ethylbenzthiazoline-
6-sulphonate) radical (ABTS+·) scavenging, ferric reducing antioxidant power (FRAP), and superoxide anion radical
scavenging assays. Results showed that BHYZ possessed significantly higher antioxidant activities than did BMD and SM
(P < 0.05), but no significant differences were observed between BMD and SM (P > 0.05). Moreover, the different kinds of
white tea had significantly different levels of amino acids, shikimic acid, and epigallocatechin gallate (EGCG) (P < 0.05).
Correlation analysis indicated that there were significant correlations between the antioxidant activities and the levels of
flavonoids, catechins and organic acids, especially EGCG and quinic acid. This study concludes that different kinds of white
tea greatly vary in their antioxidant activities and quality components.?