Prevalence and level of Listeria monocytogenes and other Listeria sp. in ready-to-eat minimally processed and refrigerated vegetables.

Minimally processed and refrigerated vegetables can be contaminated with Listeria species bacteria including Listeria monocytogenes due to extensive handling during processing or by cross contamination from the processing environment. The objective of this study was to examine the microbiological quality of ready-to-eat minimally processed and refrigerated vegetables from supermarkets in Osijek, Croatia. 100 samples of ready-to-eat vegetables collected from different supermarkets in Osijek, Croatia, were analyzed for presence of Listeria species and Listeria monocytogenes. The collected samples were cut iceberg lettuces (24 samples), other leafy vegetables (11 samples), delicatessen salads (23 samples), cabbage salads (19 samples), salads from mixed (17 samples) and root vegetables (6 samples). Listeria species was found in 20 samples (20 %) and Listeria monocytogenes was detected in only 1 sample (1 %) of cut red cabbage (less than 100 CFU/g). According to Croatian and EU microbiological criteria these results are satisfactory. However, the presence of Listeria species and Listeria monocytogenes indicates poor hygiene quality. The study showed that these products are often improperly labeled, since 24 % of analyzed samples lacked information about shelf life, and 60 % of samples lacked information about storage conditions. With regard to these facts, cold chain abruption with extended use after expiration date is a probable scenario. Therefore, the microbiological risk for consumers of ready-to-eat minimally processed and refrigerated vegetables is not completely eliminated.