Harnessing Banana Peel Waste: Development of Starch-Based Bioplastics for Green Packaging

This study investigates the isolation and characterization of starch from green banana peels and preparation of biodegradable blend films thereof. Sodium metabisulfite was found more effective than sodium bisulfite in isolating starch, resulting in a higher yield. The extracted starch was verified through FTIR, XRD, SEM, and TGA analyses. Biodegradable blend film was prepared via solvent casting with the addition of 40 wt.% glycerol as plasticizer. FTIR analysis revealed good interactions between chitosan and green banana peel starch in the blend film. X-ray diffraction, differential scanning calorimetry, and scanning electron microscopy confirmed that starch and chitosan in blend films displayed miscibility, interactions, and some microphase separation. Mechanical testing revealed that the film achieved an elongation at break of 76% when chitosan and starch were combined in equal proportions (50:50 by weight). Luminous transmittance decreased from 82% to 35% as starch content increased, while water absorption dropped from 89% to 61%. Soil burial tests demonstrated that the blend films exhibited greater biodegradability, as evidenced by higher weight loss and reduced tensile strength (0.53 MPa for CS4) compared to virgin chitosan film. Among the various formulations, the film containing 45% starch, 55% chitosan, and 40% glycerol (CS3) exhibited optimal performance, showcasing good mechanical strength, superior optical properties, effective water absorption, controlled swelling behavior, and improved biodegradability.