Effects of myrtle leaf extract and starter cultures on nitrosamine formation, oxidative stability, and quality of Salami-type products

The integration of natural antioxidants and microbial starter cultures in meat processing is increasingly recognized as a promising strategy to improve product quality, stability, and safety while reducing the presence on synthetic additives. This study investigated the effects of Myrtle Leaf Extract ( Myrtus communis L., MLE) and microbial starter cultures ( Lactiplantibacillus plantarum and Staphylococcus xylosus ) (STA) on oxidative stability, nitrosamine formation, and sensory attributes of salami-type products. At the end of the ripening period, no residual nitrite or nitrate were detected in any samples. Only N-nitroso-methylethylamine (NMEA) and N-nitrosopyrrolidine (NPYR) were identified in samples, with significantly lower levels in nitrite/nitrate-free formulations ( p < 0.05). The combination of MLE and STA further reduced nitrosamine formation, highlighting the role of microbial starters in mitigating residual nitrite through acidification and nitrite reductase activity. MLE also enhanced oxidative stability by significantly decreasing lipid oxidation, as confirmed by the thiobarbituric acid (TBA) test and rancid odour scores (r = 0.65, p = 0.001). Additionally, redness index determination revealed that samples containing microbial starters maintained a more stable cured color, even in the absence of nitrite. Microbial safety was ensured, with no detection of foodborne pathogens. Sensory evaluation indicated that MLE-treated samples exhibited color, texture, and flavor comparable to conventional nitrite/nitrate-containing samples.