Inactivation kinetics of Escherichia coli, Staphylococcus aureus, Latilactobacillus sakei and Debaryomyces hansenii on dry-cured raw ham short-term treated with low-pressure mercury vapor lamp and UV-C LED module

Abstract Irradiation with UV-C is a non-thermal decontamination treatment for food surfaces. It can be of particular interest for foods which are not usually heat treated, such as fermented, dried or cured meat products. An example of a food is dry-cured and smoked raw ham, which was short-term treated with UV-C for 5 to 60 s. Objective of this study was to determine the surface decontamination effect of short-term UV-C treatment, as higher treatment times and doses were usually applied in other studies. Quality parameters such as lipid oxidation and color were also evaluated. Raw ham samples were inoculated ( Escherichia coli , Staphylococcus aureus , Latilactobacillus sakei , Debaryomyces hansenii ) and treated with a conventional low-pressure mercury vapor (Hg-LP) lamp (mean intensity = 4.5 mW/cm 2 ) and an UV-C LED module (mean intensity = 4.2 mW/cm 2 ). Overall, the UV-C treatment resulted in a reduction of all inoculated microorganisms on raw ham, without affecting quality parameters. The antimicrobial effect was different for different microorganisms and UV-C applications. Highest reduction effect after 60 s was observed for E. coli with Hg-LP lamp (1.4 log 10 cfu/cm 2 ). The microbial inactivation effect with the Hg-LP lamp was larger even with a lower treatment dose than treatment with the LED module. Higher treatment doses did not result in significantly larger reductions of colony counts. The effect on surface decontamination was rather low as a single treatment. However, but it could be an additional measure as part of a multiple hurdle concept to reduce microbial load and improve food safety.