不同采制季节信阳白茶品质成分的比较分析

Comparative Analysis of the Quality Components in Xinyang White Teas Collected and Processed in Different Seasons

该研究采用高效液相色谱法(HPLC)等方法对春季、夏季和秋季茶树鲜叶加工而成的18款信阳白茶茶样中的8种儿茶素、6种黄酮类、2种酚酸、3种嘌呤碱等品质成分进行测定,对不同采制季节的信阳白茶进行品质成分进行对比分析。主成分分析(PCA)和聚类分析(HCA)技术均能将信阳白茶茶样按照采制季节不同进行归类,分为春季、夏季和秋季白茶。通过独立样本t-检验和单因素方差分析,探究了不同采制季节信阳白茶中儿茶素、黄酮类、嘌呤碱等品质成分差异。结果显示:不同采制季节信阳白茶中的品质成分均存在显著性(p<0.01)或极显著性(p<0.001)差异;春季白茶中(-)-表没食子酸儿茶素(EGC)、(-)-表没食子儿茶素没食子酸酯(EGCG)和鞣花酸含量极显著性(p<0.001)高于夏季或秋季白茶,含量分别为33.26、59.30、2.81 mg/g左右;夏季白茶中(-)-儿茶素没食子酸酯(CG)、(-)-没食子儿茶素没食子酸酯(GCG)、花旗松素、芦丁、杨梅素、山奈酚、槲皮素、木犀草素含量极显著性(p<0.001)高于秋季白茶,含量分别高达0.72、4.40、0.84、2.40、0.97、0.21、0.25、0.11 mg/g;秋季白茶中(+)-儿茶素(C)、(-)-表儿茶素(EC)、(-)-表儿茶素没食子酸酯(ECG)、没食子酸、咖啡碱和可可碱极显著性(p<0.001)高于夏季或春季白茶,含量分别为4.98、14.35、27.02、10.10、36.85、1.53 mg/g。该研究揭示了信阳白茶的品质特征和不同采制季节信阳白茶品质成分差异,为白茶等茶叶采制季节的识别提供了科学依据。

In this work,8 kinds of catechins,6 kinds of flavonoids,2 kinds of phenolic acids,3 kinds of purine alkaloids and other quality components contents in 18 kinds of Xinyang white teas processed from the fresh tea leaves of Spring,Summer and Autumn were analyzed by methods such as high performance liquid chromatography(HPLC).The quality components of the Xinyang white teas collected and processed in different seasons were compared and analyzed.Principal component analysis(PCA)and hierarchical clustering analysis(HCA)could classify Xinyang white tea samples into spring white tea,summer white tea and autumn white tea based on the processing seasons.Through the independent-samples t-test and one-way analysis of variance,the differences in the quality components(such as catechins,flavonoids and purine bases)of the Xinyang white teas collected and processed in different seasons were investigated.The results showed that there were significant(p<0.01)or extremely significant(p<0.001)differences in the quality components of the Xinyang white teas collected and processed in different seasons;The contents of(-)-epigallocatechin(EGC),(-)-epigallocatechin gallate(EGCG)and ellagic acid in the spring white tea(33.26,59.30 and 2.81 mg/g,respectively)were extremely significantly(p<0.001)higher than those in the summer or autumn white teas.The contents of(-)-catechin gallate(CG),(-)-gallocatechin gallate(GCG),taxifolin,rutin,myricetin,kaempferol,quercetin and luteolin in the summer white tea(0.72,4.40,0.84,2.40,0.97,0.21,0.25 and 0.11 mg/g,respectively)were extremely significantly(p<0.001)higher than those in the autumn white tea.The contents of(+)-catechin(C),(-)-epicatechin(EC),(-)-epicatechin gallate(ECG),gallic acid,caffeine and theobromine(4.98,14.35,27.02,10.10,36.85 and 1.53 mg/g)in the autumn white tea were extremely significantly(p<0.001)higher than those in the spring or summer white tea.This study revealed the quality characteristic of Xinyang white teas and the differences in the quality components of Xinyang white teas harvested and processed in spring,summer and autumn seasons.These results provide a scientific basis for the distinguishing white teas and other teas harvested and processed in different seasons.