Reduction of diazinon and dimethoate in apple juice by pulsed electric field treatment

BACKGROUND: Organophosphorus pesticides (OPPs) are widely used in agricultural production in China, and residues of OPPs in agro-products and foods have become a public health concern. Chronic exposure to OPPs can result in potential immunosuppressive effects, cytotoxicity and mutagenicity. Pulsed electric fields (PEFs) have the potential to be used as an alternative to conventional techniques of food production. The aim of the present study was to investigate the influence of PEFs on the degradation of diazinon and dimethoate added to apple juice. RESULTS: PEF treatment significantly promoted the degradation of both pesticides (P < 0.05). The extent of degradation was strongly influenced by the electric field strength and treatment time, and maximum degradation of both diazinon (47.6%) and dimethoate (34.7%) was achieved by treatment at 20 kV cm(-1) for 260 mu s. The degradation behaviour of the pesticides was described by Weibull and Hulsheger models, both of which successfully fitted the degradation of diazinon and dimethoate. In addition, the decline in the toxicity of samples was observed with a photobacterium bioassay. CONCLUSION: PEF treatment was effective in eliminating residues of diazinon and dimethoate spiked in apple juice and in mitigating sample toxicity. (C) 2011 Society of Chemical Industry