US EPA

7479046 

Journal Article 

茶叶内含物质与外源污染物在冲泡过程中的浸出规律 

Chen, H; Liu, X; Lu, C; Qiu, J 

2020 

Editorial Office of Journal of Tea science 

40 

1 

63-76 

Chinese 

Based on the recent literatures, the dissolving, releasing and transformation patterns of tea internal compounds and exogenous contaminants were summarized and discussed in this study. Physicochemical properties of chemicals and tea brewing methods are the internal and external cause affecting extraction rates of chemicals during tea brewing. Internal cause plays a crucial role in extraction rates, while external cause is more prominent for the leaching of tea internal substances. Water solubility of chemicals is positively correlated with extraction rates, while octanol-water partition is negatively correlated with extraction rates. Increasing water temperature is helpful for increasing extraction rates of chemicals and their concentrations in tea infusion. Brewing time is negatively correlated with extraction rates in a period of time, while the concentrations of chemicals in tea infusion increase with the brewing time. Compared with other pesticides, most of neonicotine pesticides and carbamate pesticides have higher extraction rates over 60%. The results of extraction rates of metal elements in tea infusion are quite different, and extraction rates of fluorine, nickel and cobalt have high extraction rates over 50%, while extraction rates of lead range from 20% to 50%. Metabonomic analysis based-high resolution mass spectrometry technique is a promising and powerful method for profiling extracting pattern of chemicals during tea brewing. Meanwhile, extracting behavior of toxic compounds during tea brewing will be deeply understood by using thermodynamic theory and kinetic model of mass extraction. © 2020, Editorial Office, Journal of Tea Science. All right reserved. 

Heavy metals; Internal substance; Leaching pattern; Pesticide residues; Tea brewing