The utilization of vaporized ethyl pyruvate for decontamination of lettuce from E. coli O157:H7

Abstract

The objective of this study was to utilize vaporized ethyl pyruvate (EP) as a means to enhance the safety of lettuce for human consumption. For this purpose, the antimicrobial activity of EP was evaluated on lettuce dipping-inoculated with Escherichia coli O157:H7 ATCC 25150. Inoculated samples for antimicrobial analysis and non-inoculated samples for organoleptic analysis (color and sensorial analysis) were treated with 0, 42, 105, and 420 ppm EP and then stored at 4 °C for 7 days and 10 °C for 5 days. Following a storage period of 7 days at a temperature of 4 °C, it was observed that the EP concentrations of 42, 105, and 420 ppm resulted in reductions of 0.8, 1.5, and 3.4 log, respectively, in the population of E. coli O157:H7 on lettuce. After a period of 5 days at a temperature of 10 °C, the presence of E. coli O157:H7 was observed to decrease by 1.3, 2.1, and 2.2 log. This reduction in bacterial count was attributed to the application of 42, 105, and 420 ppm of EP, respectively. In conclusion, based on the evaluation of organoleptic and color properties, it is suggested that the treatment involving a concentration of 42 ppm EP at 10 °C for 3 days can be a viable non-thermal method for effectively inhibiting bacterial growth.