Fresh vegetables, especially green onions and chives, are raw ingredients widely consumed by Koreans, and have been linked to Listeria monocytogenes-induced food poisoning. This study aimed to assess microbial contamination levels in commercially available fresh-cut vegetables and produce, compare the effects of different types and concentrations of disinfectants on green onions and chives, and determine the growth rate of L. monocytogenes on chives under different storage conditions. Among the five fresh-cut vegetable mix salad products, the average total mesophilic count (TMC) was 2.00 log CFU/g, whereas the crown daisies exhibited the highest levels of raw produce contamination (TMC of 4.14 log CFU/g). The disinfection experiments indicated the elevated disinfectant capacities of electrolyzed water as well as washing under running water against Escherichia coli and L. monocytogenes. Enhanced anti-TMC ability of electrolyzed water were observed in acidic 30 ppm (pH 3.2) and 60 ppm (pH 5.6) of HOCl, and alkaline 100 ppm (pH 8.1) and 200 ppm (pH 8.8) of NaClO. Moreover, in the L. monocytogenes inoculation experiment in chive, the growth rates at 5 °C, 12 °C, and 30 °C were −0.002, 0.023, and 0.030 log CFU/g/h, respectively. This observation suggests that L. monocytogenes cannot grow on chives if stored at 5 °C but can at 12 °C. This study provides scientific evidence to guide the management of microbial quality of fresh produce and fresh-cut vegetables for safer meal provision in home and eating-out settings.
An et al. (Mon,) studied this question.