Transfer of pesticide residue during tea brewing: Understanding the effects of pesticide's physico-chemical parameters on its transfer behavior

The percent transfer of pesticide residue from tea to infusion is an important factor that should be taken into consideration for setting realistic Maximum Residue Levels (MRLs) and risk assessment, as infusion prepared from dry tea is generally consumed, rather than the dry tea. The aim of this study is to investigate the inherent regularity of pesticides' transfer behavior, and to understand the effects of pesticide's physico-chemical parameters on its transfer behavior. A series of field trials, manufacturing and brewing experiments of 42 pesticides were conducted. Results indicated that transfer potential of a pesticide is related to its physical–chemical properties but not much to its type. Regression of transfer rate (TR) prediction model was logTR = 1.242 + 0.306log(Ws) (R2 = 0.893). Thus, water solubility (Ws) can be used to predict the drinking safety of pesticides potentially introduced into tea plantation. Furthermore, as a case study on tea, this approach could also provide references for other beverage crops. [Display omitted] •Transfer potential of pesticide is related to physical–chemical parameters than type.•Factors for pesticides' transfer can be rationalized by physico-chemical properties.•Empirical model for transfer rate prediction was developed as logTR = 1.242 + 0.306logWs.•Transfer rate kept >80% with logWs>3 and no longer sensitive to the variation of Ws.•Transfer of many pesticides in tea could provide an insight for other beverage crops.