Physical and antimicrobial properties of sodium alginate/carboxymethyl cellulose films incorporated with cinnamon essential oil

Antimicrobial sodium alginate/carboxymethyl cellulose (SA/CMC) films were prepared by using glycerol as plasticizer, cinnamon essential oil (CEO) as antimicrobial agent, and Tween® 80 as surfactant. The effects of CEO concentration on the microstructure and physical, barrier, mechanical, and antimicrobial properties of SA/CMC films with Tween® 80 were investigated. It was found that the incorporation of CEO increased the thickness, water vapour permeability, oxygen permeability, and elongation at break of the films and significantly reduced the moisture content and tensile strength. However, water vapour permeability was reduced when 15 g/L CEO was incorporated into the films. The oxygen permeability of films slightly decreased with increasing Tween® 80 concentration. Moreover, SA/CMC films containing CEO exhibited excellent antimicrobial activity for Escherichia coli and Staphylococcus aureus. With increasing CEO amount to 15 g/L, the inhibitory effects on Staphylococcus aureus increased with increasing amounts of Tween® 80. In addition, film-forming solutions with CEO were used as coatings for the preservation of bananas. The results showed that the coatings could extend the shelf life of bananas.