Development of Strategies to Minimize the Risk of Listeria monocytogenes Contamination in Radish, Oriental Melon, and Carrots

Contamination by Listeria monocytogenes in packaged produce is a major concern. The purpose of this study was to find natural and affordable sanitizers to reduce L. monocytogenes contamination in agricultural products. Organic acids, ultraviolet-C (UV-C), and ethanol were analyzed either alone or in combination to assess their ability to reduce L. monocytogenes population in radish, oriental melon, and carrot samples. In radish samples, 3% malic acid combined with UV-C at a dosage of 144 mj/cm(2) significantly reduced (>4 log CFU/g) the population of L. monocytogenes (1.44 +/- 0.5) compared to the control sample (5.14 +/- 0.09). In the case of the melon samples, exposure to UV-C at a dosage of 144 mj/cm(2) combined with 3% lactic acid (2.73 +/- 0.75) or 50% ethanol (2.30 +/- 0.01) was effective against L. monocytogenes compared to the control sample (5.10 +/- 0.19). In carrot samples, 3% lactic acid combined with 144 mj/cm(2) dosage UV-C reduced L. monocytogenes population (4.48 +/- 0.25) more than in the control sample (5.85 +/- 0.08). These results reveal that sanitizers that are effective for one crop are less effective for another crop indicating that effective prevention methods should be customized for each crop to prevent pathogen cross contamination during postharvest washing.