Work

Climatic dependence of the C, N stable isotope ratios and their contents of Guangxi green tea

Year: 2024

Type: article

Abstract: The stable carbon (C) and nitrogen (N) isotopic ratios and their concentrations in green tea were ascertained across distinct harvest periods within a microclimate setting. The findings revealed statistically significant variations in the δ 15 N (1.67 ± 2.60 ‰ to 4.47 ± 0.68 ‰), N% (4.59 ± 0.38 % to 6.18 ± 0.48 %), and δ 13 C (-27.91 ± 0.65 ‰ to −25.99 ± 0.95 ‰) values among tea samples collected at different harvest periods ( p < 0.05). Typically, these isotopic parameters exhibited an initial depletion indicative of climatic influence, succeeded by an enrichment phase. In contrast, C% demonstrated minimal variation across harvest periods ( p > 0.05), which consistently ranged from 45.93 ± 4.02 % to 47.44 ± 1.01 %. Redundancy analysis and Pearson correlation elucidated the impact of climatic variability on isotopic fractionation within the tea samples. Specifically, δ 15 N values displayed a significant positive correlation with temperature and solar irradiance but a negative correlation with other climatic elements. Conversely, N% exhibited an inverse correlational trend relative to δ 15 N under identical conditions. For δ 13 C, a predominantly negative correlation with climatic factors was observed. The study has delineated the influence of climatic fluctuations on the isotopic composition of tea, offering a valuable theoretical basis for enhancing traceability through stable isotope-based methodologies.

Source: Journal of Food Composition and Analysis

DOI: 10.1016/j.jfca.2024.107105