Growth potential of three strains of Listeria monocytogenes and Salmonella enterica in Frescal and semi-hard artisanal Minas microcheeses: Impact of the addition of lactic acid bacteria with antimicrobial activity

This study aimed to determine the growth potential (delta) of L. monocytogenes (CLIST 3974, CLIST 3969, and CLIST 4162) and S. enterica [S. Typhimurium (ATCC SM 14028), S. Enteritidis (SM 64), and S. Montevideo (SM 129)] in the presence of a pool of lactic acid bacteria (LAB) with antimicrobial activity in Frescal and semi-hard Minas microcheeses. The delta was determined after storing Frescal cheese at 4 and 7 degrees C for 15 days and the and semi-hard Minas cheese during ripening (22 degrees C for 22 days). The delta of L. monocytogenes was significantly higher in Frescal Minas cheese with no added LAB (p > 0.05). On the other hand, in semi-hard cheese inoculated with LAB, inactivation of L. monocytogenes was observed. No significant differences were found in the delta of S. enterica in Frescal Minas cheese inoculated with LAB at 4 and 7 degrees C. S. enterica SM 14028 and SM 129 could grow in semihard cheeses non-inoculated with LAB, while when LAB was inoculated, S. enterica was inactivated. The findings of this study indicated that the delta of L. monocytogenes strains was more affected in cheeses inoculated with LAB than the delta of S. enterica.