Pulsed Light Treatment Effect on Color, Oxidative Stability, and Listeria monocytogenes Population of Sliced Mortadella

This study evaluated the effects of high-intensity pulsed light (PL) on sliced mortadella, assessing how the parameters pulse width (1260 to 2520 µs) and number of pulses (one to three) influence color, oxidative stability, and <i>Listeria monocytogenes</i> population. The different PL parameters generated a fluence ranging from 2.64 to 6.57 J/cm² and irradiance ranging from 1046.9 to 1738.8 W/cm². The PL slightly increased the temperature and pH of the samples, and this elevation was well correlated to the higher number of pulses and higher fluence. The color parameter a* was reduced while b* values increased after PL application, with these effects being more significant in treatments with a higher number of pulses and higher fluence. The highest values of TBARS were found in treatments with higher fluence (5.28 and 6.57 J/cm²), which were characterized by the attribute "oxidized color" in sensory evaluation. The different PL conditions reduced the count of <i>L. monocytogenes</i> by up to 1.44 Log CFU/cm². The treatment with a pulse width of 1260 µs, two pulses, fluence of 4.38 J/cm², and irradiance of 1738.3 W/cm² achieved the same efficacy in pathogen reduction as the treatments with higher fluence. Moreover, these PL conditions had a minimal impact on the color and oxidative stability of mortadella, demonstrating an effective balance between microbiological safety and quality preservation.