Physical Properties and Antimicrobial Activities of Soy Protein Isolate Edible Films Incorporated with Essential Oil Monomers
In this study, physical properties and antimicrobial activity of soy protein isolate edible films incorporated with essential oil monomers were tested. Adding amount of essential oil monomers could significantly change the physical properties of the films. Water-solubility of soy protein isolate edible films could be significantly reduced when adding essential oil monomers. With the essential oil monomers’ content increasing, the water vapor permeability increased at the beginning and then decreased. Tensile strength reduced with cinnamicaldehyde and eugenol content increasing, but the tensile strength of cinnamaldehyde-eugenol (1:1) compound films reduced at first and then increased. The breaking elongation of cinnamaldehyde-eugenol (1:1) compound edible films was the highest. Using cinnamaldehyde, eugenol and cinnamaldehyde-eugenol (1:1) compound as the antibacterial agent respectively, antibacterial activities of soy protein isolate edible films incorporated with1, 2, 3, 4, 5and6% essential oil monomer were evaluated against Escherichia coli, we found that antibacterial activities of soy protein isolate edible films incorporated with essential oil monomers were significant, film containing cinnamaldehyde was the most effective.