Nitrite reduction in mortadella using gamma irradiation and chitosan: Effects on quality and Clostridium botulinum outgrowth

Reducing nitrite levels in cured meat products remains a major challenge due to its key role in controlling Clostridium botulinum . This study evaluated the combined effects of chitosan (0 and 1.5%), sodium nitrite (0, 50, and 150 mg/kg), and gamma irradiation (0, 2, 4, and 6 kGy) on C. botulinum control (stored at 4 °C for 30 days) and technological quality of mortadella. Chitosan and irradiation effectively controlled C. botulinum regardless of nitrite level, with irradiation showing a dose-dependent effect. In the absence of chitosan, spores were inactivated at 6 kGy, and no viable cells were recovered at 4 kGy after storage. With 1.5% chitosan, 2 kGy was sufficient for spore inactivation, and no viable cells were detected after storage in non-irradiated samples containing nitrite. Treatments did not affect ( P > 0.05) chemical composition of mortadella, but chitosan addition reduced ( P < 0.05) lipid oxidation (0.68 vs. 0.53 mg malondialdehyde/kg), elasticity (0.869 vs. 0.834), and chewiness (44.57 vs. 40.92 N), while increased ( P < 0.05) residual nitrite (13.78 vs. 8.77 mg/kg) and lightness (L*). Irradiation did not affect ( P > 0.05) the oxidative or cured color stability of mortadella during the 30-days storage period. Overall, the combination of 1.5% chitosan, 50 mg/kg nitrite, and 2 kGy irradiation effectively controlled C. botulinum while maintaining the technological quality of mortadella, indicating a viable strategy to reduce nitrite levels in cured meat products.