Low dose UV-C illumination as an eco-innovative disinfection system on minimally processed apples

• UV-C illumination completely inhibits growth of foodborne pathogens in in vitro.
• UV-C illumination, at 1.0 kJ/m2 reduced foodborne pathogens in fresh-cut apple.
• UV-C illumination did not affect the quality parameters of fresh-cut apple.

In this study, the efficacy of UV-C illumination for inactivate Escherichia coli, Listeria innocua or Salmonella enterica, individually or in a mixture, in vitro and on apple slices was determined. Apple slices inoculated with a 107 cfu/mL suspension of above indicated pathogens were irradiated on both sides with UV-C illumination, with doses of 0.5 and 1.0 kJ/m2. UV-C illumination disinfection efficacy was compared to that of washings with sodium hypochlorite at 100 ppm of free chlorine and with distilled water. Bactericidal activity of each treatment was assessed after 30 min and after 7 and 15 days of storage at 4 °C. Results showed that UV-C illumination at 1.0 kJ/m2 could be an alternative to the wash with hypochlorite solutions. On the in vitro study, these doses completely inhibited the growth of the three bacteria either as pure cultures or in a mixture. In fresh-cut apple, the pathogens were also affected by the UV-C illumination, the 1.0 kJ/m2 dosage being the one that resulted in higher bacteria inhibition in almost every case. The UV-C treatment did not affect the quality properties of fresh-cut apple.