Antibacterial efficacy of ethyl pyruvate treatment against Escherichia coli O157:H7 and Salmonella Typhimurium on cherry tomatoes

Abstract

Cherry tomatoes inoculated with Escherichia coli O157:H7 and Salmonella Typhimurium were treated with vaporised ethyl pyruvate (EP). The changes of microbial and organoleptic properties of the samples during storage were investigated at two temperatures (4 and 10 degrees C) and four EP concentrations (0, 42, 105, and 420 ppm) for 7 days at 4 degrees C and for 5 days 10 degrees C. After 3 days, 4.3 log and 3.6 log reductions in E. coli O157:H7 numbers were detected in cherry tomatoes treated with 42 ppm EP at 4 degrees C and at 10 degrees C, respectively. The highest EP treatment (420 ppm) led to 5.7 log CFU g(-1) E. coli O157:H7 reduction after 1 day at 4 and 10 degrees C. The reduction of Salmonella Typhimurium on samples treated with 420 ppm EP was 7.7 log CFU g(-1) after 1 day at 4 degrees C, and 6.9 log after 1 day at 10 degrees C. The treatment of EP can be effective at decreasing pathogen populations and can protect the organoleptic and colour properties of fresh produce.