Eggshell Reinforced Yam Starch-Based Bioplastic for Packaging Applications

The massive manufacture and usage of plastic causes a significant environmental problem and increases the severity of global warming. The existing problem can be controlled by producing bioplastic from natural sources. In this study, the bioplastics films were developed from yam starch (Dorceasea) which is reinforced with different concentrations of eggshell by using the solvent casting technique. Further, the bioplastic films were characterized by scanning electron microscope, Fourier transform infrared spectroscopy, static contact angle, tensile testing, swelling test, soil biodegradation, solubility, and water vapor transmission rate test. The purity of native yam starch was also tested through an iodine colorimetric assay, which showed 24.5% amylose and 75.5% amylopectin contents. Scanning electron microscope revealed oval and spheroidal rounded structures for starch granules. The intensity and the hydrophilicity of films slightly decreased with an increase in the eggshell concentrations due to the covalent bonding of carbonate with the glycoside group, which was confirmed by Fourier transform infrared spectroscopy and static contact angle analysis. In addition, the tensile strength of films was improved with the increase in filler (eggshell) concentration, i.e., 0.97 ± 0.06 MPa for N4 film. The filler-reinforced films were observed to be degrading steadily in soil which is almost 56% after 21 days for 3% eggshell. Also, they exhibited a reduced water vapor transmission rate which is essential for the shelf life of bioplastics. Therefore, Yam starch-based bioplastic films can substitute synthetic plastic for packaging applications that can prove to be environmentally benign.