Effect of ozone, lactic acid and combination treatments on the control of microbial and pesticide contaminants of fresh vegetables

BACKGROUND Fruit and vegetable consumption has increased among masses due to their tremendous health benefits. However, recent studies have shown that contaminated products may serve as a vehicle for foodborne pathogens and harmful chemicals. Therefore, fresh vegetables must be decontaminated before consumption to ensure food safety. RESULTS In this study, the combined decontamination treatment of lactic acid (2.5 ml L-1) and ozone (9 mg L-1) for 10 min showed better efficacy in the removal of contaminants from fresh vegetables as compared to individual treatments. The combined treatment resulted in a reduction of 1.5- 3.5 log CFU of native mesophilic bacteria g-1 and 1.6- 2.9 log CFU of artificially inoculated Escherichia coli g-1 from tomato, cucumber, carrot and lettuce. The combined treatment also removed spiked pesticides, which represents an artificial chemical contamination (28- 97 % chlorpyrifos and 62- 100 % λ-cyhalothrin residues) from the fresh vegetables. No significant difference (p>0.05) in various sensory attributes of vegetables was observed between untreated and treated (lactic acid and ozone) vegetables. CONCLUSION The combination treatment provides a novel approach to target two groups of contaminants using a single procedure. The combination treatment can be used as an alternative to currently used decontamination techniques for the supply of safe vegetables to consumers. This article is protected by copyright. All rights reserved.