Evaluation of antimicrobial properties and diffusion of carvacrol from active zein films for food packaging applications

The aim of this study was assess the application of carvacrol at 5 and 10% levels in production of the zein film and evaluation of its antimicrobial properties, and also kinetics release of carvacrol from active film (10%w/w) in food simulants of acetic acidand ethanol at different temperatures by using high performance liquid chromatography from. Diffusion and the activation energy (Ea) values of zein film containing 10% carvacrol were calculated based on Fick’s second law. Results showed that by increasing temperature from 4 to 37°C, the extent of releasing after 60 min in acid simulant (9.82 ± 1.34 to 40.78 ± 0.06 %(, and ethanol simulant (11.80 ± 1.34 to 47.44 ± 0.06%) was increased. The diffusion value of carvacrol at 4, 22 and 37°C in acetic acid simulant was determined 0.23, 1.20 and 6.70 m.s, respectively. The Ea value for carvacrol diffusion in 3% acetic acid simulant (72.75 kJmol-1) was lower than in ethanol simulant (79.73 kJ mol-1). The antibacterial activity of zein films was studied against Escherichia coli and Listeria monocytogenesin at 4 and 37°C. The zein films containing 5% carvacrol produced a good bactericidal effect. It was observed total inhibition against Escherichia coli by incorporating 10% carvacrol in zein film at both temperatures. This work suggested that the zein bioplastics containing carvacrol can be used as an active packaging for improving the safety and shelf-life of food products.