摘要
Abstract
In order to explore the differences in nutritional components and the characteristics of mineral elements in Oolong teas from Fujian Province,eight representative Oolong teas(including Wuyishan Dahongpao,Wuyishan Rougui,Wuyishan Shuixian,Zhao'an Baxian Tea,Nan'an Tieguanyin,Zhangping Shuixian Tea,Yongfu Gaoshan Tea,Datian Meiren Tea)from four producing areas of northern Fujian,southern Fujian,western Fujian and central Fujian were selected as the research objects.The contents of nutritional components(including ash,moisture,crude fiber,tea polyphenols,total flavonoids,soluble sugar,crude polysaccharide,water extract,catechins,free amino acids)and mineral elements(including potassium,calcium,magnesium,zinc,iron,manganese,copper,aluminum,selenium)were systematically determined.Then,the comprehensive evaluation was performed by using the correlation analysis,principal component analysis and cluster analysis.The results showed that the coefficients of variation for soluble sugars,catechins,and total free amino acids in the eight representative Fujian Oolong teas all exceeded 46%,which were the key components leading to the differences in tea soup taste.The correlation analysis revealed a significant positive correlation between the total free amino acid content and calcium content in Oolong tea.The cumulative contribution rate of the five principal components extracted by further principal component analysis was 93.571%,which could effectively distinguish the quality characteristics of different Oolong teas.Among them,Zhangping Shuixian tea and Yongfu Gaoshan tea showed the best comprehensive evaluation.The results of cluster analysis showed that the measured samples showed obvious regional aggregation:Oolong teas in northern Fujian exhibited a mellow style with abundant mineral content;the components of Oolong teas in western Fujian were rich,with full and fresh taste;Oolong teas in southern Fujian displayed diverse styles and high aroma;while Oolong teas in central Fujian showed unique characteristics.The results provided an important reference for the establishment of regional quality identification,the optimization of processing technology and market development of Fujian Oolong tea.关键词
福建乌龙茶/营养成分/矿质元素/相关性分析/主成分分析/聚类分析Key words
Fujian Oolong tea/Nutritional components/Mineral elements/Correlation analysis/Principal component analysis/Cluster analysis分类
农业科技
