Development and Characterization of Turmeric Oil-Loaded Cassava Starch/Chitosan Composite Film Coatings for Sustainable Food Packaging

Abstract

Conventional plastic packaging is widely used because of its durability, low cost, and effective barrier properties; however, its non-biodegradability raises substantial environmental and potential food-safety concerns that may undermine sustainable food systems and food-security efforts. This study aimed to develop and characterize a biodegradable composite film containing cassava starch, chitosan, carboxymethyl cellulose, glycerol, and turmeric oil as a coating for sustainable food-packaging paper. Uncoated paper (UP) and coated paper (CP) were characterized using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), tensile-strength testing, antimicrobial-sensitivity testing, and contact-angle measurements. SEM revealed a porous surface with loosely packed fibers in UP, whereas CP exhibited a uniform, continuous layer, confirming effective coating formation. FTIR spectra of CP showed characteristic O–H (3200–3400 cm⁻¹) and C–H (2800–2900 cm⁻¹) stretching vibrations associated with cellulose and hemicellulose. Increased loading enhanced O–H, C–H, C=O, C–O, and aromatic C=C signals, indicating improvements in hydrophobicity, mechanical integrity, barrier performance, and turmeric-oil-derived antioxidant activity. TGA demonstrated minimal initial mass loss, followed by a major degradation stage between 250 and 450 °C attributable to cellulose and hemicellulose decomposition; mass loss above 450 °C was negligible. CP1 exhibited greater tensile strength (44.28 MPa) than UP (37.86 MPa), while the coating solution displayed shear-thinning behavior and a pH of 5.6. UP produced no inhibition zone, whereas CP5 showed the largest inhibition zone (6.0 mm) and enhanced hydrophobicity, with water and oil contact angles of 95.4° and 101°, respectively. These findings demonstrate that the composite coating improves the mechanical, thermal, barrier, and antimicrobial properties of paper, supporting its potential application as a biodegradable material for sustainable food packaging.