Impact of Pulsed UV Light on Listeria monocytogenes Decontamination and Biochemical Properties of Fermented Sliced Beef Sucuk

Traditional fermented sucuk is one of the most commonly consumed fermented meat products in Turkey. During both production and post-production, sucuks can easily become contaminated with pathogenic microorganisms such as Salmonella, L. monocytogenes, and E. coli O157, originating from the slaughtered animal, the surfaces in the production environment, or workers. Pulsed UV (PUV) light is a next-generation preservation method that can be used against both chemical and thermal methods to eliminate contamination on food surfaces. PUV light is a technique that has the potential to be especially effective in eliminating microorganisms from ready-to-eat foods. In this study, the effect of PUV light applied at a wide range of energy doses on L. monocytogenes pathogens on the surface of sliced sucuk was investigated. The upper surface of the sucuk slices was contaminated with L. monocytogenes. Experimental samples were exposed to PUV light at distances of 5, 8, and 13 cm from the quartz window in the PUV light system for 5, 15, 30, 45, and 60 seconds. The energy range applied was between 4.35 and 98.78 J/cm². In samples treated for 60 seconds at distances of 5 cm and 8 cm from the light source, the number of L. monocytogenes was found to be below detectable levels. The highest microorganism density in sucuk samples was in the total mesophilic aerobic bacteria group (6.32 log10 cfu/g), followed by lactic acid bacteria (4.43 log10 cfu/g) and yeast-mold (3.29 log10 cfu/g). Coliform bacteria and Listeria monocytogenes were found at lower levels (5.58 log10 cfu/g).  Furthermore, there was a decrease in the L*, a*, and b* color values in all experimental samples. Regarding lipid oxidation levels, an increase was detected in sucuk samples with high fat content, while no significant change was observed in samples with low fat content. The findings of this study confirm the efficacy of pulsed UV light as a disinfection method against hazardous pathogens such as Listeria monocytogenes. However, prolonged exposure and short-distance application of pulsed UV light were found to have significant impacts on the color characteristics of food products.