Effect of Rice Bran Addition on Physical Properties of Antimicrobial Biocomposite Films Based on Starch

Abstract

The increase in consumer requirements for safe and high-quality food has promoted the development of active and edible packaging materials based on biopolymers. In this study, composite tapioca starch films by addition of processed rice bran (PRB) microparticles, containing or not the natural antimicrobials natamycin and nisin, were studied in relation to their physicochemical properties and antimicrobial activity. It was observed that the presence of PRB addition (0.1–0.3% w/w) increased yellowness proportionally to fiber content in films with or without antimicrobials but did not influence on thickness and water vapor permeability. Films with 0.2% PRB allowed the highest increase of tensile strength and strain at break and reduced the solubility in water, showing the optimal compatibility between PRB and starch matrix containing or not antimicrobials. Analysis by FTIR also suggested a good compatibility between filler and matrix through hydrophilic groups. Additionally, the analyzed composite films allowed the diffusion of the natural preservatives verified through zones of inhibition formed in the halo test against Saccharomyces cerevisiae and Listeria innocua. Consequently, the developed biocomposites can be used as an active packaging for food preservation.