COMPARISON OF OZONE AND CHLORINE FOR REDUCING MICROBIAL LOAD ON LETTUCE LEAVES (original) (raw)

Potential organic compatible sanitisers including electrolysed water (EW, 4 mg/L free available chlorine (FAC)), citric acid (0.6%), H 2 O 2 (1%), and their combinations were applied on organic and conventional fresh-cut lettuce (Lactuca sativa Var crispa L.) to evaluate their effects on microbiological safety, physi-cochemical parameters and sensory analysis (including raw sample and boiled sample). The combination of 1% H 2 O 2 with 0.6% citric acid led to the highest reductions of microbial loads (2.26 log CFU/g for aerobic mesophilic count (AMC) and 1.28 log CFU/g for yeasts and moulds); however, it also caused the highest electrolyte leakage rate (3.11% vs. 0.91% for control). The combination of EW with 1% H 2 O 2 achieved 1.69 and 0.96 log CFU/g reductions for AMC and yeasts and moulds, respectively with elec-trolyte leakage rate of 1.41%. In terms of the content of polyphenolic compounds, firmness, colour and raw material sensory analysis, there were no significant differences among different treatments, and between organic and conventional counterparts. The results suggest that 1% H 2 O 2 combined with 4 mg/L EW is a promising approach for treating organic fresh-cut lettuce.