Design of a nitrite-free dry-cured fermented “salchichón” process preventing growth of Salmonella, Listeria monocytogenes, and Staphylococcus aureus

The processing of nitrite-free dry-cured fermented "salchichón" has been modified and evaluated to know its efficacy in preventing the growth of the pathogenic bacteria L. monocytogenes, Salmonella, and S. aureus. For this, two ripening processes of "salchichón" were performed: a first ripening process to design the best conditions of cold ripening, for preventing the growth of the mentioned pathogens; and a second one with the already established most optimal cold conditions of processing. In both ripening processes L. monocytogenes, Salmonella, and S. aureus and two lactic acid bacteria (LAB) (a selected Latilactobacillus sakei and a commercial culture), were inoculated. The decrease of moisture and pH of the "salchichón" during initial cold ripening for 22 days at 5 °C, to reach values of 40 % (a_w below 0.93) and 5.5, respectively, were critical for the reduction of L. monocytogenes, Salmonella, and S. aureus in all of the inoculated batches, even after further ripening at 15 °C for 30 days. In addition, inoculated LAB acted summatively with the decrease of a_w and pH in the reduction of these pathogenic bacteria. In the second ripening process of "salchichón" using the above selection conditions, significant reductions of 2.8, 4.4, and 2.9 log CFU/g of L. monocytogenes, Salmonella, and S. aureus, respectively were found throughout the complete ripening process. Thus, the processing of nitrite-free "salchichón" combining an initial cold ripening at 5 °C and the use of LAB cultures prevents the growth of accidental contaminations of L. monocytogenes, Salmonella and S. aureus that could take place during processing.