Residue levels, processing factors and risk assessment of pesticides in ginger from market to table

Ginger is consumed as a spice and medicine globally. However, pesticide residues in ginger and their residue changes during processing remain poorly understood. Our results demonstrate that clothianidin, carbendazim and imidacloprid were the top detected pesticides in 152 ginger samples with detection rates of 17.11%–27.63%, and these pesticides had higher average residues of 44.07–97.63 μg/kg. Although most samples contained low levels of pesticides, 66.45% of the samples were detected with pesticides, and 38.82% were contaminated with 2–5 pesticides. Peeling, washing, boiling and pickling removed different amounts of pesticides from ginger (processing factor range: 0.06–1.56, most <1). By contrast, pesticide residues were concentrated by stir-frying and drying (0.50–6.45, most >1). Pesticide residues were influenced by pesticide physico-chemical parameters involving molecular weight, melting point, degradation point and octanol–water partition coefficient by different ginger processing methods. Chronic and acute dietary risk assessments suggest that dietary exposure to pesticides from ginger consumption was within acceptable levels for the general population. This study sheds light on pesticide residues in ginger from market to processing and is of theoretical and practical value for ensuring ginger quality and safety. Few pesticides have been registered on ginger in China, which causes the abuse of pesticides on ginger and has a negative impact on the environment. Hence, this study is the first to investigate the pesticide residues in both the kind and level of ginger from market to table. Furthermore, residue changes of pesticides during processing were assessed, processing factors were calculated and the correlation between processing factors and pesticide physico-chemical properties was determined. This study helps identify if pesticides present any health issues and is useful to ensure food safety and guard human health.