Enhanced removal of phoxim pesticide residues from grapes using microbubble plasma-activated water

A novel, rapid, and efficient technique for removing phoxim residues from grapes was developed using microbubbles plasma-activated water (mbPAW). The mbPAW system was generated by utilizing a non-thermal plasma jet as the working gas of the Venturi tube. The phoxim residues in the grapes were quantified using high-performance liquid chromatography. Results indicated that the mbPAW treatment significantly enhanced the removal efficiency of the phoxim residues in grapes (92.82%) compared with plasma-activated water (PAW) treatment (73.60%) and microbubble generator without the plasma (mbW) treatment (13.56%). The improved decontamination efficacy of mbPAW was attributed to its stronger oxidation capability and acidic environment, particularly the increased concentration of hydroxyl radicals, which facilitated phoxim removal from the grapes. Notably, LC-Q-TOF analysis revealed identical degradation products of phoxim (diethyl ( Z )-(((cyano(phenyl)methylene)amino)oxy)phosphonate and ( Z ) -N -hydroxybenzimidoyl cyanide) in both the systems, confirming consistent degradation pathways. Crucially, post-treatment quality assessments revealed no statistically significant differences in grape physicochemical properties, including color, firmness, sugar content, vitamin C concentration, and superoxide dismutase activity. This study establishes mbPAW as a green, residue-free strategy for pesticide decontamination in horticultural products, offering high removal efficiency with minimal adverse impacts on produce quality. • mbPAW is developed for the removal of phoxim residue from grapes. • mbPAW achieves a phoxim removal ratio of 92.82%, surpassing both PAW and microbubble water. • mbPAW boosts phoxim degradation by enhancing oxidative capacity and acidity. • mbPAW preserves the sensory and nutritional quality of grapes.