Release of antimicrobial components of Zataria multiflora Boiss. essential oil from bio active zein film into food simulants

Antimicrobial active packaging is a novel technology that controls the growth of microorganisms in perishable food products with releasing of active components. In this work, the chemical composition of Zataria multiflora Boiss. essential oil (ZEO) was analyzed by GC/MS. The main components of the essential were carvacrol (37.22%), thymol (28.44). Active bio composite of zein films, containing 10% essential oils of thyme, were developed. Kinetics release of the active compound is strongly related to food models. The kinetics and extent of carvacrol and thymol mass transport within the packaging components were evaluated by using high performance liquid chromatography from bioactive films zein into simulants (10% ethanol and 3% acetic acid) at 4°C and 37°C. The antibacterial activity of active zein films was evaluated. The results of this studied indicated that the release of the active compound was strongly related to food models. The extent of releasing of carvacrol and thymol after 60 min at 4°C in acid simulant (11.93±1.34 and 1.40±0.06ppm, respectively) was more than that of ethanol simulant (7.60±0.22 and 0.98±0.02ppm, respectively). SEM observations confirmed the influence of food simulants on structure of zein, related to releasing of active components of essential oil into food simulants. The releasing rate of carvacrol and thymol increased with increasing the temperature to 37°C. Active zein film containing 10% ZEO was more stable in ethanol simulant at 4°C. The log reduction value of zein bioactive composite film against Listeria innocua andEscherichia coli were calculated to be 2.75 and 3.07, respectively.