Efficacy of pulsed light for shelf-life extension and inactivation of Listeria monocytogenes on ready-to-eat cooked meat products

Abstract Pulsed light (PL) was tested for its utility to improve the microbial quality and safety of ready-to-eat cooked meat products. Vacuum-packaged ham and bologna slices were superficially inoculated with Listeria monocytogenes and treated with 0.7, 2.1, 4.2 and 8.4 J/cm 2 . PL treatment at 8.4 J/cm 2 reduced L. monocytogenes by 1.78 cfu/cm 2 in cooked ham and by 1.11 cfu/cm 2 in bologna. The effect of PL on lipid oxidation and sensory properties was also investigated. The 2-thiobarbituric acid values were very low and chromaticity parameters were within the normal values reported for cooked meat products. PL at 8.4 J/cm 2 did not affect the sensory quality of cooked ham, while treatments above 2.1 J/cm 2 negatively influenced the sensory properties of bologna. The combination of PL and vacuum packaging provided ham with an additional shelf-life extension of 30 days compared with only vacuum packaging. The shelf-life of bologna was not extended by PL. Industrial relevance The efficacy of pulsed light for the decontamination of surfaces offers excellent possibilities to ensure food safety and to extend shelf-life of ready-to-eat (RTE) products. The results of this study indicate that Listeria monocytogenes can be reduced by approximately 2 log cfu/cm 2 in RTE cooked ham and 1 log cfu/cm 2 in bologna using a fluence of 8.4 J/cm 2 . This dose does not affect the sensory properties of ham and triples its shelf-life when compared with conventional RTE products. On the contrary, fluences above 2.1 J/cm 2 are not suitable for the treatment of bologna since sensory quality is modified.