Development of an active packaging based on polyethylene containing linalool or thymol for mozzarella cheese

The aim of this research was to evaluate the effect of active polyethylene film (PE) containing linalool and thymol active components on the microbial shelf life of mozzarella cheese. PE films containing different concentrations of linalool or thymol (0%, 1%, 1.5% and 2%) were prepared. The antimicrobial properties of the films were examined, and mozzarella cheese was packed with these active films. The antimicrobial properties of packed samples during 30 days of storage were studied. The obtained results from film tests showed that by increasing the concentration of active agents (linalool and thymol) in PE films, the antimicrobial activities of film samples against Escherichia coli, Staphylococcus aureus, Listeria innocua, and Saccharomyces cervicea were increased. The cheese tests result demonstrated that mozzarella cheese packaging with PE films containing different concentrations of linalool and thymol leads to a decreased growth rate of molds and yeasts in cheeses. At the end of the storage period, the lowest number of molds and yeasts was for a sample packed in PE film containing 2% thymol, which increased from 1.00 to 1.21 Log CFU/g during the storage period. From E. coli and S. aureus contamination, the samples packed in active films were safe until the last day of storage (30th day), while the control sample was unacceptable at 17th day of storage. According to obtained results from this study, it was concluded that the addition of linalool and thymol active components to PE film had a positive effect on the extension of the mozzarella scheese shelf life.