基于相关性和主成分分析的上犹名优绿茶品质评价

目的 比较8种上犹名优绿茶的品质化学成分。方法 对8种上犹名优绿茶进行感官审评和品质化学成分检测，采用相关性分析和主成分分析对结果进行综合评价。结果 8 种上犹名优绿茶感官品质综合得分由高到低排序为: T2>T6>T5>T4>T3>T1=T8>T7; 8种名优绿茶水浸出物含量为32.62%~51.75%, 可溶性糖含量为4.31%~5.15%，可溶蛋白含量为1.92%~2.22%，茶多酚含量为15.43%~18.97%, 游离氨基酸含量为3.24%~5.71%, 咖啡碱含量为3.52%~4.08%, 黄酮含量为0.39%~0.54%; 相关性分析结果显示，儿茶素与可溶性糖、茶多酚呈显著正相关（P＜0.05），与游离氨基酸呈极显著负相关（P＜0.01）；咖啡碱与滋味呈显著正相关（P＜0.05），与香气呈极显著正相关（P＜0.01）。采用主成分分析法对8个茶样建立综合得分数学模型Y= 0.4848Y1+ 0.1829Y2+ 0.1456Y3, 综合得分由高到低依次是: T3＞T1＞T5＞T7＞T2＞T6＞T4＞T8。结论 上犹名优绿茶品质化学成分含量丰富, 整体品质优良, 研究结果将为上犹名优绿茶的生产加工和品质提升提供一定的理论依据。

Quality analysis of Shangyou famous green tea based on correlation and principal component analysis

Objective To compare the quality of 8 kinds of famous green tea in Shangyou. Methods Sensory evaluation and quality chemical composition detection of famous green tea in Shangyou were carried out. And the results were comprehensively evaluated by correlation analysis and principal component analysis. Results The comprehensive sensory evaluation scores of 8 kinds of famous green tea ranked from high to low was as follows: Wuzhifeng Yunpian>Junlingminghao>Youshizhang Maojian>Zhongyi Huangjinye>Taoshichaye> Yingqianwuhao= Guanggushan Maojian>Youjianglvye Maojian. There was a certain difference in the content of chemical composition, 32.62%?51.75% for water extract, 4.31%?5.37% for soluble sugar, 1.92%?2.22% for soluble protein, 15.37%?18.97% for tea polyphenol, 3.24%?5.71% for amino acid, 3.52%?4.08% for caffeine and 0.39%?0.61% for flavonoids. The correlation analysis results showed that there was a weak positive correlation between the water extract, the soluble sugar, tea polyphenols and the color of the tea infusion, and a weak positive correlation between the soluble sugar and the tea infusion aroma, respectively, the free amino acids were positively correlated with taste, the caffeine was positively correlated with taste and aroma (P<0.05), and the correlation coefficients were 0.81 and 0.85, respectively. The mathematical model of comprehensive score was established for the 8 kinds of tea samples by principal component analysis: Y=0.4848Y1+0.1829Y2+0.1456Y3, and the comprehensive scores in descending order were as follows: Taoshichaye>Yingqianwuhao>Youshizhang Maojian>Youjianglvye Maojian> Wuzhifeng Yunpian>Junlingminghao>Zhongyi Huangjinye>Guanggushan Maojian. Conculsion Shangyou famous green tea is rich inquality chemical composition, the quality evaluation method established in this study will provide data supports for the production process optimization and quality grade evaluation of Shangyou famous green tea.