Microbial inhibition in mozzarella cheese using rosemary and thyme oils in combination with sodium diacetate

Abstract

The effectiveness of rosemary and thyme oils as antimicrobial agents in mozzarella cheese against Listeria monocytogenes, lactic acid bacteria (LAB), and total aerobic bacteria (TAB) was evaluated. In low fat cheese, rosemary and thyme oils inhibited L. monocytogenes by 0.5 and 1.0 log CFU/g, respectively, and by 1.7 log CFU/g in combination on day 20 at 4°C. Combination of rosemary and thyme oils inhibited growth of L. monocytogenes and LAB in low fat cheese, but not in full fat cheese. Rosemary and thyme oils with sodium diacetate were more effective for inhibition of L. monocytogenes than oil alone. Essential oils have potential applications for inhibition of indigenous microorganisms in low fat food products, and for controlling growth of L. monocytogenes after post-processing contamination. The oils also showed potential for inhibition of microorganisms in full fat products in combination with sodium diacetate.