2018 ASHS Annual Conference

Fresh-cut fruits and vegetables are increasingly being recognized as important vehicles for transmission of human pathogens such as Salmonella enterica, and Listeria monocytogenes. Understanding the population dynamics of these foodborne pathogens on cut fruits and vegetables stored at different temperatures is critical to improve food safety. We evaluated the survival and growth of S. enterica and L. monocytogenes on different types of fresh-cut melons and other produce which were exposed to different temperature abuse conditions during seven days of storage. Produce items were purchased from a local wholesale market, including fresh-cut cantaloupe, honeydew, watermelon, pineapple, and radish, cut to cuboid pieces of approximately 8 cm3 and placed into 4 oz portion cups for storage at 4^oC until inoculated with a cocktail of three S. enterica (SE) serovars and a L. monocytogenes (LM) cocktail consisting of three serotypes of L. monocytogenes and stored under different temperatures (4, 8, 12 and 35 °C). The results indicated that, under chronic temperature abuse conditions of 8 and 12 ^oC, all cut melon samples supported significant growth of the inoculated foodborne pathogens, with S. enterica populations reaching up to 5.28 log CFU/g and L. monocytogenes up to 7.77 log CFU/g. On the other hand, neither S. enterica nor L. monocytogenes showed any significant growth on fresh-cut radish and pineapple at all the temperatures investigated, with those on fresh-cut pineapple exhibiting rapid population decline. Temperature abuse can foster the proliferation of pathogens in fresh-cut fruits and vegetables. This study showed the potential for Salmonella and L. monocytogenes survival and growth at a variety of temperatures on cut cantaloupe, watermelon, honeydew, pineapple and radishes, highlighting the importance of maintaining an uninterrupted cold chain for TCS (temperature control for safety) foods and the need for strict controls to prevent or minimize the presence of pathogens before, during, and after the processing of these fruits and vegetables.