Research – Determination of Listeria monocytogenes, competitive microflora, microbial hygiene indicators and physico-chemical parameters during the shelf-life of the typical Mediterranean style fermented sausage “Salsiccia Sarda”

Journal of Food Protection

The aim of the present study was the determination of Listeria monocytogenes , competitive microbiota, microbial hygiene indicators and physico-chemical parameters in the typical Mediterranean Style fermented sausages “Salsiccia Sarda” . A batch of “Salsiccia Sarda” (25 samples) naturally contaminated by L. monocytogenes and vacuum packaged after 24 days of ripening was included in the study. Fifteen samples stored at 8° C were analysed after 13, 90 and lastly at the end of shelf-life, after 180 days from vacuum packaging. Ten vacuum packaged samples were stored at 12°C in a domestic fridge simulating temperature abuse and were evaluated at the end of the shelf-life. Samples were subjected to physico-chemical analysis (pH and aw) and investigated for the presence and enumeration of L. monocytogenes . Competitive microbiota, Lactic Acid Bacteria (LAB) and Coagulase negative Staphylococci (CNS), and microbial hygiene indicators (Total mesophilic bacterial counts, Enterobacteriaceae, Enterococcuss spp. and Staphylococcus aureus ) were determined in all the samples. Although a decreasing trend in L. monocytogenes prevalence was observed through the shelf-life, the detection of the pathogen in fermented sausages confirms the ability of L. monocytogenes to overcome the hurdles of the manufacturing process. The results of the present study highlight the importance to carefully evaluate the “Salsiccia Sarda” production process by Food Business Operators (FBOs) in order to maintain unfavourable conditions for the growth of L. monocytogenes .