Physiochemical properties and food application of antimicrobial PLA film

Antimicrobial polylactic acid (PLA) films releasing allyl isothiocyanate (AIT) vapor were developed. The physicochemical properties and water vapor and gas permeability characteristics of the films were investigated, and the antimicrobial properties in vapor phase in food application were evaluated. The results reveal that the resultant antimicrobial (AM) PLA films had less strength, less stiffness and more flexibility, a lower O-2 and CO2 transmission rate, and a higher UV absorption rate than the pure PLA films. Avrami's equation showed the best fit with experimental release data (R-2 > 0.91) and indicated the release kinetics of AIT from the AM PLA film could be a combined mechanism of diffusion and first-order model. AM film treatment (4 x 8 cm film in 1 L box) significantly (p < 0.05) inhibited total aerobic bacterial growth in fresh pak choi stored at 4 and 10 degrees C for 15 days. The AM film treated pak choi had less color change and chlorophyll loss than the control samples during storage. The AM PLA film has the potential to be utilized for extending the shelf-life of various perishable food products. Published by Elsevier Ltd.