Development and characterization of chitosan edible film incorporated with epoxy-activated agarose

Abstract

Backround: Chitosan is a linear polysaccharide, which has promising characteristics to be used as a packaging film. In this study chitosan-based edible films incorporated with epoxy-activated agarose (EAA) at different levels [5, 10, 15, and 20% (w/w of chitosan)] were developed by casting method and their physicochemical and barrier properties were evaluated. Results: Addition of EAA to chitosan produced translucent and flexible films. Fourier transform infrared spectroscopy (FT-IR) revealed functional groups of chitosan and EAA interacting via hydrogen bonds. Tensile strength, moisture content, swelling power, film solubility, and the thermal stability of the films were declined by 65%, 12%, 50%, 13%, and 68%, respectively, with increasing concentrations of EAA up to 15%. Whereas film thickness, opacity, and elongation at break significantly increased by 23%, 69%, and 160%, respectively. In particular, the elongation of the composite films and the opacity was doubled that of the pure chitosan film when 20% EAA was incorporated. The color variations between pure chitosan and chitosan-EAA films were minimal. Scanning electron microscopic (SEM) images showed that at higher concentrations of the EAA, the films produced had a slightly rougher surface. Conclusion: This study indicates that the addition of EAA at appropriate levels to chitosan can improve the physicochemical properties of chitosan-based edible composite films, which may find potential applications in food packaging.