Metabolic mechanism exploring tea nutrients based on stable isotope fractionation and element accumulation

This study primarily investigated the variations in stable isotope ratios and elemental fingerprints in tea leaves, which are influenced by multiple factors such as tea cultivars, plant parts, geographical areas, and harvest times. Statistical analyses revealed significant differences in isotope and elemental profiles among tea cultivars. By employing advanced statistical methods, such as principal component analysis (PCA), hierarchical cluster analysis (HCA), and linear discriminant analysis (LDA), we achieved 100% accuracy in classifying tea cultivars. Additionally, different parts of the tea plant and geographical areas exhibited substantial impacts on the concentrations of stable isotopes and elements. The variation in harvest times further indicated the regulation of isotope fractionation and element accumulation. The variations in carbon (C), nitrogen (N), and oxygen (O) isotopes among different tea tree parts illuminated the pathways of nutrient transport within the plant. Overall, plant parts were identified as the most crucial factor affecting tea quality, followed by geographical areas and tea cultivars. These findings provide scientific evidence for tea classification and quality control, while also enhancing the understanding of the nutritional metabolism mechanisms in tea plants.