22种不同来源信阳毛尖茶的分类比较

为了探究采制时节、产地、等级等因素对信阳毛尖茶品质成分的影响，本文采用高效液相色谱等方法对22个不同来源的信阳毛尖茶中儿茶素、黄酮类、酚酸类、嘌呤碱等品质成分进行测定。主成分分析、聚类分析和偏最小乘法-判别分析显示采制时节是影响信阳毛尖品质成分的主要因素，不同来源信阳毛尖基本可按照采制时节分为明前、雨前和春尾。单因素方差分析显示不同采制时节信阳毛尖茶在8种儿茶素、5种黄酮类、2种嘌呤碱以及没食子酸、游离氨基酸等品质成分上存在极显著差异(P<0.01):明前茶中的游离氨基酸总量和(+)-儿茶素(C)含量最高、而(+)-没食子儿茶素(GC)、(-)-表没食子儿茶素(EGC)、(-)-表儿茶素没食子酸酯(ECG)、(-)-表没食子儿茶素没食子酸酯(EGCG)、没食子酸、芦丁、杨梅素、槲皮素、可可碱含量最低，与雨前茶和春尾茶存在显著(P<0.05)或极显著差异(P<0.01)。不同产地和等级之间C、ECG、(-)-表没食子儿茶素(EGC)等儿茶素；芦丁、花旗松素、杨梅素等黄酮类；以及可可碱、茶碱等嘌呤碱含量存在显著(P<0.05)或极显著差异(P<0.01)。相对而言，四望山毛尖茶中非酯型儿茶素含量较高，而黄酮总量较低；芽头中游离氨基酸和C含量最高，而EGC和杨梅素含量最低，这对信阳毛尖采制时节的识别有一定影响。本文首次基于茶叶中品质成分对不同来源的信阳毛尖进行了分类比较，为明前茶的识别提供了科学依据。

Classification and Comparative Analysis of 22 Xinyang Maojian Teas with Various Origins

To find out the impacts of picked-processing duration, production place and grade on quality components in Xinyang Maojian tea, contents of catechins, flavonoids, phenolic acids and purine alkaloids in 22 Xinyang Maojian teas with various origins were determined by HPLC. PCA, HCA and PLS-DA confirmed that picked-processing duration was the main influence factor of quality components in teas, and various Xinyang Maojian teas were divided into Mingqian, Yuqian and Chunwei basically based on the picked-processing duration. One-way analysis of variance showed the highly significant differences (P<0.01) of 8 catechins, 5 flavonoids, 2 purine alkaloids, gallic acid and free amino acids among three picked-processing duration. Mingqian tea had highest contents of total free amino acids and (+)-catechin (C), but the lowest contents of GC, EGC, ECG, EGCG, gallic acid, rutin, myricetin, quercetin and theobromine, which showed the significant (P<0.05) or highly significant differences (P<0.01) compared with Yuqian and Chunwei. The significant (P<0.05) or highly significant differences (P<0.01) of catechins (i.e. C, ECG, EGC), flavonoids (i.e. rutin, taxifolin and myricetin), and theobromine and theophylline were found in Xinyang Maojian tea between different production place and grades. Relatively speaking, Maojian tea produced in Siwang hill had relatively higher content of non-ester catechins and lower total content of flavonoids, while Maojian tea of bud head grade had the highest contents of free amino acids and C, and lowest contents of EGC and myricetin, which had certain impact on the identification of picked-processing duration. This study was the first time to classify and compare Xinyang Maojian teas from various origins based on the quality components in tea, which provided the scientific evidences for the identification of Mingqian tea.