Synergistic Effects of Short‐Term <scp>UV</scp> ‐C Exposure Combined With Low‐Dose Nisin Against <i>Listeria innocua</i> : Enhancing Microbial Safety While Preserving Quality Attributes in Minimally Processed Vegetable Salad

ABSTRACT This study aimed to evaluate the effects of UV‐C light intensity and exposure time on quality indicators of a minimally processed vegetable salad (50% purple lettuce, 25% arugula, and 25% beet leaves) as well as to assess the effectiveness of its combination with nisin in enhancing microbial safety against Listeria innocua . Preliminary assays established maximum irradiation times to preserve total polyphenols and ascorbic acid: 90 s for low intensity (L‐I: 0.036 kJ/s·m 2 ) and 60 s for high intensity (H‐I: 0.070 kJ/s·m 2 ). While individual UV‐C treatments (up to 10 s) resulted in reductions of 0.5–1.0 log cycles, the combination with nisin (250–500 IU/g) led to enhanced microbial inactivation, with immediate reductions exceeding 5 log cycles in all cases. Notably, the application of a low nisin dose (125 IU/g) followed by UV‐C (0.3 kJ/m 2 ) demonstrated a superior bacteriostatic effect over 6 days under high‐contamination scenarios. Under more realistic contamination levels (10 5 CFU/g), this combination maintained undetectable Listeria counts for 7 days, complying with European food safety standards. These results demonstrate a synergistic hurdle effect, providing a practical and scalable approach to enhance the microbial safety and quality of ready‐to‐eat vegetable products.