基于主成分分析法评价昆明市宝洪茶绿茶品质指标

Evaluation of quality indicators of Camellia sinensis cv Baohongcha. green tea in Kunming based on principal component analysis

中文关键词:  宝洪茶  绿茶  品质  主成分分析  指标评价

英文关键词:Camellia sinensis cv Baohongcha.  green tea  quality  principal component analysis  indicator evaluation

中文摘要:

      目的 评价昆明市宝洪茶绿茶品质, 并明确其品质关键指标。方法 利用皮尔逊相关性分析、系统聚类分析和主成分分析法对昆明市主产区宜良县抽取的31批次样品中水浸出物、茶多酚、儿茶素、游离氨基酸(以谷氨酸计)、茶氨酸、咖啡碱、茶黄素、多糖(以葡萄糖计)、总黄酮(以芦丁计)等9项品质指标进行研究。结果 通过主成分分析法将9项单项测定指标综合成相互独立的两个指标F1、F2, 两个指标的贡献率分别为41.33%、15.20%, 累计贡献率为56.53%, 并得出水浸出物、茶多酚、儿茶素、咖啡碱、茶氨酸和游离氨基酸6个品质指标为关键评价指标。结论 针对宝洪茶绿茶6个关键品质指标进行了深入剖析, 发现其指标数据整体较好, 形成宝洪茶汤色黄绿明亮、入口鲜爽回甘, 香气四溢的高香型绿茶特点, 建议进一步加强宝洪茶全产业链标准体系建立。

英文摘要:

      Objective To evaluate the quality of Camellia sinensis cv Baohongcha. green tea in Kunming, and identify its key quality indicators. Methods A total of 9 quality indicators, including water extract, tea polyphenols, catechins, free amino acids (calculated as glutamic acid), theanine, caffeine, theaflavins, polysaccharides (calculated as glucose) and total flavonoids (calculated as rutin), were determined in 31 batches of Camellia sinensis cv Baohongcha. green tea samples collected from Yiliang County, the main producing area of Kunming. Pearson correlation analysis, hierarchical cluster analysis and principal component analysis were adopted for data analysis. Results The 9 individual indicators were integrated into 2 independent comprehensive components F1 and F2 by principal component analysis. The contribution rates of F1 and F2 were 41.33% and 15.20%, respectively, with a cumulative contribution rate of 56.53%. The 6 key evaluation indicators were screened out, namely water extract, tea polyphenols, catechins, caffeine, free amino acids and theanine. Conclusion The 6 key quality indicators of Camellia sinensis cv Baohongcha. green tea are analyzed in depth. The results shows that the overall quality indicators of Camellia sinensis cv Baohongcha. tea are excellent, which endows the tea with typical characteristics of high-aroma green tea: Yellowish-green and bright liquor color, fresh and brisk taste with sweet aftertaste, and rich fragrance. It is suggested to further construct and optimize the standard system for the whole industrial chain of Camellia sinensis cv Baohongcha. tea.