Antioxidant and antimicrobial carboxymethyl cellulose films containing Zataria multiflora essential oil

Abstract

The present study describes the physical, antioxidant, and antimicrobial properties of biodegradable films prepared by incorporating different concentrations (1, 2, and 3% v/v) of Zataria multiflora Boiss (avishan-e shirazi) essential oil (ZEO) into carboxymethyl cellulose (CMC) film. The films’ tensile strength, elongation at break, water-vapor permeability, optical characteristics, microstructure, and antimicrobial and antioxidant properties were investigated. The results indicated that the film containing 1% ZEO had the highest tensile strength and elongation at break. The control film showed the lowest water-vapor permeability. The resulting optical data showed that the control films were transparent in appearance; transparency was significantly reduced by an increase in ZEO concentration. Solubility in water decreased with increased ZEO. Films with ZEO, especially at higher concentrations, were more effective against all tested bacteria than the control film. Those films incorporating essential oil revealed antioxidant properties as well; this effect was greatly improved when the proportion of ZEO was increased. The results indicated that the antioxidant and antibacterial activity of ZEO is retained when it is used in CMC film. These properties with some good physical characteristics suggest applications for ZEO-incorporated film in a wide range of food products.