Inactivation of Salmonella enterica ser. Poona and Listeria monocytogenes on fresh-cut “Maradol” red papaya (Carica papaya L) treated with UV-C light and malic acid

In recent years, the consumption of fresh-cut fruit has been associated with outbreaks of diseases caused by different emerging pathogenic microorganisms. Therefore, great efforts to find methods that ensure the quality and safety of minimally processed products are needed. The main objective of this study was to evaluate the effect of different doses of UV-C light (0, 0.96, 2.88, 5.76 and 8.64 kJ/m2) and treatments with malic acid (0, 0.5, 1.0 and 1.5 %, w/v) applied into dipping solutions containing calcium lactate (1 %, w/v) and ascorbic acid (0.5 %, w/v) on the inactivation of Salmonella enterica ser. Poona and Listeria monocytogenes inoculated onto fresh-cut “Maradol” papaya (0.7 × 3.5 × 2.5 cm). Significant differences (p ≤ 0.05) in counts of Salmonella Poona and L. monocytogenes on fresh-cut papaya, treated with different doses of UV-C light and different concentrations of malic acid, were observed. A synergistic effect between malic acid (1.5 %) and UV-C light (8.64 kJ/m2) was noted. Reductions of 5.28 and 3.15 Log10 CFU/g for Salmonella Poona and L. monocytogenes, respectively, were reached using this combination. In conclusion, the combination of dipping solutions containing malic acid and treatment with UV-C light could be a good alternative to ensure the safety of minimally processed papayas.