Production of edible film based on starch-montmorillonite containing green tea extract in order packaging of flax seed oil

Starch-based active packaging which contain additives has been used to food preservation, significantly. Organic nano-clays such as montmorillonite cause to strength of these films and additives such as antioxidants reduces food spoilage rate. In this study starch-based films with different percentages of montmorillonite from 0 to 8% and the green tea extract from 0 to 2.5 % were produced by casting method and physical properties of the films such as tensile strength, water absorption, water vapor permeability and solubility were investigated. Then flax seed oil was packaged in these films and some chemical properties of oil, peroxide index and acidity, were evaluated. Then the optimal point in the film production was determined with Minitab 17 software by response surface methodology. The results showed that low content of both independent factors caused to decrease of water absorption and solubility and addition of montmorillonite and green tea extract increased the tensile strength of films. It was seen in medium content of both factor water vapor permeability of films was the least. Montmorillonite in high and medium content caused to reduction of peroxide index and acidity, respectively. Organoleptic tests showed that edible films did not change the odor, flavor, color and overall acceptance of flax seed oil, too. The optimal point to justify was in 2.42% of Montmorillonite and 0.181% of green tea extract caused to increase shelf life of flax seed oil to 7 days.