Development and characterization of defatted pumpkin seed meal and halloysite nanoclay composite films for food packaging

The valorization of agricultural by-products into sustainable packaging materials is one of the best strategies to utilize industrial waste efficiently. In this study, defatted pumpkin seed meal (DPSM) has been converted into films by impregnating selected concentrations of halloysite (HS) nanoclay (1%, 2% and 3% w/w). Various analytical techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and barrier property measurements, were employed to characterize the developed films. The appearance of the roughness on the surface of the films was evident from SEM micrographs upon the addition of HS. No change in the crystallinity of DPSM occurred when HS was incorporated; however, the T-g showed a variation with the loading concentration of the clay. Fourier transform infrared spectroscopy (FTIR) spectroscopy indicated that the decrease in hydrogen bonding was associated with increasing the HS concentrations. The addition of HS improved the tensile strength, stress relaxation percentage and Young's modulus, while the elongation at break was reduced at a similar condition. The biodegradability of the film was excellent within 20 days of the burying period. Overall, the developed films could be a potential candidate for sustainable food packaging.