Design of biodegradable and antimicrobial PLA-based films incorporating banana waste cellulose and LAE for active food packaging

The development of biodegradable packaging materials based on polylactic acid (PLA) constitutes a novel strategy to counteract the dependence of plastics derived on fossil sources. In this framework, the exploitation of agrifood waste as well as adding antimicrobial properties to packaging materials also highlights a cutting-edge approach for this purpose. In this research, cellulose was extracted from banana rachises via alkaline treatment. The effective obtention of biopolymer was confirmed through Fourier Transform Infrared Spectroscopy and a 64% extraction yield was achieved. A 25:75 cellulose and PLA ratio was mixed with ethyl lauroyl arginate (LAE) at 10 and 20% (w/w) to obtain biodegradable and antimicrobial films. The thickness, opacity, structural and water vapor barrier properties at 33% and 97% relative humidities of antimicrobial films were tested. The adding of cellulose significantly increased the film thickness and opacity. Adding LAE at 20% resulted in antimicrobial films with lower opacity and water vapor permeability at 97% RH. The antimicrobial activity was tested against Escherichia coli and Staphylococcus aureus through disk diffusion method. A better antimicrobial activity against Gram positive bacteria was shown by both films. These findings suggest potentially suing these bioplastics for food industry applications as an ecofriendly solution to prevent microbial contamination.