Survival and Growth of Foodborne Pathogens in Minimally Processed Vegetables at 4 and 15 degrees C

Abstract

We conducted this study to investigate the survival and growth of pathogens on fresh vegetables stored at 4 and 15 degrees C. Vegetables (romaine lettuce, iceberg lettuce, perilla leaves, and sprouts) were inoculated with 4 pathogens (Salmonella enterica serovar Typhimurium, Staphylococcus aureus, Listeria monocytogenes, and Escherichia coli O157:H7) and stored at 2 different temperatures for different periods of time (3, 6, 9, 12, and 15 d at 4 degrees C and 1, 2, 3, 5, and 7 d at 15 degrees C). Populations of the 4 pathogens tended to increase on all vegetables stored at 15 degrees C for 7 d. Populations of E. coli O157:H7 and S. Typhimurium increased significantly, by approximately 2 log10CFU/g, on loose and head lettuce stored at 15 degrees C for 1 d. No significant differences were observed in the growth of different pathogens on vegetables stored at 4 degrees C for 15 d. E. coli O157:H7 did not survive on sprouts stored at 15 or 4 degrees C. The survival and growth of food pathogens on fresh vegetables were very different depending on the pathogen type and storage temperature.