A Study on Quality Differences Between Shandong Green Tea and Low-Latitude Green Tea

Shandong, the tea-growing region at the highest latitude in China, leverages its unique climatic environment and geographical advantages to produce numerous high-quality green teas, including Rizhao Green Tea. Thus, By investigating the differences in leaf characteristics and physicochemical aspects between green teas from Shandong and those grown at varying altitudes in low-latitude regions of southern China, this study aimed to uncover the unique qualities of Shandong green teas. Correlations between leaf characteristics, sensory quality, and physicochemical components in tea samples from the four provinces were analyzed, elucidating the intricate relationships among these three indicators. Through PLS-DA and significance difference analysis of 34 physicochemical components, 14 significantly different components were selected on the basis of the criteria of VIP > 1 and p < 0.05. Notably, four major components—water extract, free amino acids, caffeine, and total polyphenols—were found to be abundant in the Shandong samples, while the phenol-to-ammonia ratio was ideally balanced between 4.5 and 5.5, contributing to the highest sensory evaluation scores. The findings of this study provide scientific insights for tea production, facilitating the optimization and upgrading of the tea industry and enhancing its market competitiveness.