不同品种青砖茶化学成分与抗氧化活性的比较分析

本研究第一次分析比较了赤壁群体种、中茶108、槠叶齐和丹桂品种所制青砖茶在感官品质、化学成分及抗氧化活性方面的差异。采用顶空固相微萃取-气相色谱-质谱仪联用技术,对4个品种青砖茶样品挥发性成分进行了分析鉴定。结果表明,不同品种青砖茶的化学成分含量有明显差异;总抗氧化能力、抑制羟自由基能力和DPPH自由基清除能力以中茶108、槠叶齐和丹桂所制青砖茶较高;相关性分析表明青砖茶茶汤的抗氧化活性主要与茶多酚、儿茶素类化合物总量以及咖啡碱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(EGCG)和苹果酸的相关性最强;可溶性糖、反-2-癸烯醛、壬醛与感官评分呈极显著正相关,而没食子酸、3-甲基呋喃、苯乙酮、异佛尔酮等与感官评分呈极显著负相关;不同品种青砖茶的醛类、酮类和醇类化合物具有明显的差异,其中丹桂品种所制青砖茶的品种香明显,与其芳香醛和酮类物质含量较高相关;感官审评结果显示,4个品种所制青砖茶的品质无显著差异。通过对不同品种青砖茶的主要品质化学成分含量、抗氧化活性以及感官品质等分析,为青砖茶品种选育及其应用提供参考依据。

Comparative Analysis of Chemical Constituents and Antioxidant Activities of Different Cultivars of Qingzhuan Tea

In this study, the differences in sensory quality, chemical composition and antioxidant activity of tea infusions made from Chibiquntizhong, Zhongcha108, Zhu yeqi and Dangui cultivasr were investigated for the first time. The volatile components of four different varieties of Qingzhuan tea were analyzed using headspace solid-phase micro-extraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The result showed that significant differences were observed in the chemical compositions of Qingzhuan teas made from four different varieties. The total antioxidant activity, ability to inhibit hydroxyl free radicals, DPPH free radical scavenging activity of Qingzhuan teas made from Zhongcha108, Zhu yeqi and Dangui cultivars were higher; Correlation analysis revealed the significant correlations between the antioxidant activity of Qingzhu tea and the total amounts of tea polyphenols and catechins and total amount of caffeine, in particular, the correlations with EGCG and malic acid were the strongest; the sensory score was positively correlated with the contents of water-soluble sugars, trans-2-decenal and nonanal, while negatively correlated with the contents of gallic acid, 3-methylfuran, acetophenone and isophorone; There were significant differences in aldehydes, ketones and alcohols among the different varieties of Qingzhuan teas, and the unique aroma of Dangui cultivar was related to the abundant aromatic aldehyde and ketones. Sensory evaluation revealed that there was no significant difference in the sensory quality of Qingzhuan teas made from the four varieties. The analyses of major chemical components, antioxidant activities and sensory quality of different varieties of Qingzhuan tea would provide an important reference for breed selection and application of tea varieties.