Recently, the innovation team of tea quality and risk assessment of the Tea Research Institute of the Chinese Academy of Agricultural Sciences has made new progress in the research on the pollution and risk assessment of pyrrolizidine alkaloids (PAS) in tea. Aiming at the problem of PAS pollution in tea that is of global concern, the team established a high-sensitivity analysis method for 15 kinds of PAS in tea and weeds, revealed the degradation law and leaching behavior in the process of tea processing and brewing, and identified the typical mechanism of PAS hepatotoxicity. Relevant research results were published on food chemistry, food control and toxins.
PAS and its N-oxides (Panos) are a kind of plant secondary metabolites with a series of toxic effects, such as hepatotoxicity, pulmonary toxicity, carcinogenicity and so on. The European Union EFSA lists pas/panos in tea and substitute tea as one of the main sources of human exposure to PAS, and as the main monitoring safety index for the export of EU tea and substitute tea. In this study, a highly sensitive and accurate uplc-ms/ms method was developed to simultaneously detect 15 kinds of pas/panos in tea and weeds. It was clarified that the degradation rate of Panos in the process of tea processing (43.9%- 79.2%) and the leaching rate of Panos in the process of brewing (≥ 75.84%) were significantly higher than that of PAS (degradation rate ≤ 26.4%, leaching rate ≤ 56.53%), and Panos could be transformed and reduced to the corresponding PAS in the process of tea processing for the first time, The direct evidence of hepatotoxicity induced by typical PAS melanokines in tea through mitochondrial mediated apoptosis was identified. This study provides basic data for the risk assessment of PAS in tea and the formulation of the maximum allowable limit standard in tea and alternative tea.
The research was supported by the innovation project of the Chinese Academy of Agricultural Sciences, national risk assessment and other projects.