Comprehensive Evaluation of Nutritional Components and Mineral Elements in Eight Representative Oolong Teas from Fujian Province Based on Multivariate Statistical Analysis

To investigate the differences in nutritional components and the characteristics of mineral elements in Oolong teas from Fujian Province, eight representative Oolong teas from four major production regions—Northern Fujian, Southern Fujian, Western Fujian, and Central Fujian were selected as research objects. These included Wuyishan Dahongpao, Wuyishan Rougui, Wuyishan Shuixian, Zhao'an Baxian Tea, Nan'an Tieguanyin, Zhangping Shuixian Tea, Yongfu Gaoshan Tea, and Datian Meiren Tea. Their nutritional components（including ash, moisture, crude fiber, tea polyphenols, total flavonoids, soluble sugars, crude polysaccharides, water extract, catechins, total free amino acids）and mineral element contents（including potassium, calcium, magnesium, zinc, iron, manganese, copper, aluminum, selenium）were systematically determined. Comprehensive evaluation was performed using 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%, indicating these as key components responsible for differences in tea soup taste. Correlation analysis revealed a significant positive correlation between the free amino acid content and calcium content in Oolong tea. Further principal component analysis extracted five principal components with a cumulative contribution rate of 93.571%, effectively distinguishing the quality characteristics of different Oolong teas, among which Zhangping Shuixian tea and Yongfu Gaoshan tea showed the best comprehensive evaluation. Cluster analysis results demonstrated clear regional clustering among the tested samples: Northern Fujian Oolong teas exhibited a mellow style with abundant mineral content; Western Fujian Oolong teas were rich in components with a full and fresh taste; Southern Fujian Oolong teas displayed diverse styles and high aroma; while Central Fujian Oolong tea showed unique characteristics. This study provides important scientific basis for establishing geographical quality identification, optimizing processing techniques, and market development of Fujian Oolong tea.