Food Safety in Bacon by Cultures: Efficiency Proof by Challenge Testing and Metagenomics Analysis

Introduction: Bio-protection is the practice of adding selected safe bacteria to foods in order to inhibit the growth of unwanted microorganisms. The process consists in substituting hurdles or adding additional ones that pathogens and spoilage bacteria cannot surmount while pursuing a clean labeling strategy. Through the inhibition of bacterial growth, microbial quality is improved but also color, texture, taste deviation could be avoided.

Purpose: This strategy was successfully used to improve the quality of cured bacon particularly to control Listeria monocytogenes and Staphylococcus aureus growth during its process and its shelf life. 

Methods: To demonstrate the efficiency of SafePro^® B-LC-77 (Pediococcus acidilactici and Staphylococcus carnosus) such a culture was applied (addition into the brine before its injection into pork bellies) during a bacon process. To check the right implantation of both strains from the SafePro^®B-LC-77 metagenomic analyses were performed at the beginning and at the end of the bacon shelf life. In addition challenge tests were conducted to evaluate the growth potential of both pathogenic bacteria during the ripening (15 h at 95°F), the most sensitive step of the bacon process and the shelf life of the meat product.

Results: It was demonstrated that both strains from SafePro^® B-LC-77 strongly dominate the endogenous flora from bacon during the whole shelf life. The addition of such an ingredient allowed a 2-log decrease of the L. monocytogenes concentration during the ripening step and another 2-log during the 28 days of storage at 68°F. In addition, the growth of S. aureus was also totally inhibited during the ripening and the bacon shelf life.

Significance: The use of culture can thus be considered as a natural anti-microbial agent to suppress and/or limit the growth of pathogenic bacteria in meat products.