Preparation of Oregano Essential Oil-Carboxymethyl Cellulose Active Packaging Films and Their Antioxidant and Antibacterial Properties

The objective of this study was to prepare a biodegradable active packaging film with antioxidant and antibacterial properties by blending oregano essential oil with carboxymethyl cellulose. The structure and properties of membranes with 0%,1%,2% and 3% essential oil were investigated by thickness meter,color difference meter,texture meter,infrared spectrum and scanning electron microscope. The results showed that the essential oil increased the thickness of the films in a certain extent and made the surface of the films looks pale brownish-yellow. The elongation at break of the films showed no significant change as the concetration of the essential oil increase,however the strength of extension reduced significantly. The essential oil was combined with carboxymethyl cellulose,and micropore appeared on the membrane surface,which could release it to play the role of antioxidation and antimicrobial. The results of infrared spectrum showed that the addition of oregano essential oil did not react with carboxymethyl cellulose. By measuring DPPH free radical scavenging rate,it was found that the addition of oregano essential oil could significantly improve the antioxidant capacity of the film with the increase of concentration,but the difference between 2% and 3% was not significant(p>0.05). It was found by agar diffusion that essential oil could significantly inhibit the growth of Staphylococcus aureus and Escherichia coli,and the bacteriostatic effect increased significantly with the increase of the amount of essential oil(p<0.05). Considering the property and the cost of our film,it was concluded that the carboxymethyl cellulose film containing 2% bovine essential oil has good physical performance and better performance of antioxidant and antibacterial.