Development and Characterization of Salvia macrosiphon/Chitosan Edible Films

With the aim of manufacturing environmentally friendly and antimicrobial edible films for packaging applications, we explored biofilms based on a blend of Salvia macrosiphon seed mucilage (SSM) and chitosan, which is studied for the first time, prepared at different ratios by drying of the colloidal solution at the end. It was observed that hydrogen bonding occurs between these two carbohydrates, and at higher concentrations of chitosan, it dominates as the matrix. The addition of chitosan to SSM leads to conservable improvement of the mechanical properties compared to the neat SSM, with 65% enhancement of the tensile strength. Thermal property studies of prepared blends showed a single glass transition temperature, which is indicative of good miscibility in all temperature ranges. Moreover, the blended biofilms showed excellent barrier properties against water in comparison with neat SSM as the addition of chitosan leads to greater hydrophobicity. The chitosan also improved the barrier properties of SSM against UV light while also enhancing its transparency (at 600 nm) at lower concentrations. Morphological studies clearly showed the dispersion of chitosan in the matrix and a corresponding increase in roughness of the biofilms. Additionally, the antibacterial activity of the biofilms improved with increasing chitosan content without using any antimicrobial agent. As a result of these combined characteristics, the SSM/chitosan biofilms are appropriate candidates for edible and eco-friendly packaging applications as they can keep fruits more fresh in an eco-friendly sustainable way and reduce the fruit waste.