Modeling microbial growth in Minas Frescal cheese under modified atmosphere packaging

The purpose of this study was to evaluate and model the growth of psychrotrophs and lactic acid bacteria in Minas Frescal (MF) cheese packed under modified atmosphere (vacuum, 20% CO2/40% N-2, 40% CO2/60% N-2,N- and 60% CO2/40% N-2) and stored at 7 degrees C for 21 days. Results indicate that psychrotrophs and lactic acid bacteria growth were declined as CO2 concentration increase in the packaging. Primary mathematical models were able to predict microbial growth in MF cheese under different modified atmosphere packaging (MAP). The maximum specific growth rate of psychrotrophs and lactic acid bacteria was reduced in approximately 55 and 60%, respectively, using 60% CO2/40% N-2 MAP (compared with cheese packed under vacuum). Results from the secondary mathematical model suggest that the sensitivity to CO2 in psychrotrophs and lactic acid bacteria was similar. This research reports new information about the impact of MAP on the microbial growth in MF cheese. Practical applications This study could successfully be utilized to control the microbial growth of MF cheese. The modified atmosphere packaging used in this research can be scaled up for commercial manufacturing. High CO2 level (60% CO2/40% N-2 MAP) have a similar effect on psychrotrophs and lactic acid bacteria in MF cheese. Exploring the effect on MAP on microbiological growth in MF cheese is important to manufacture the products with consistent quality on industrial scale.