Active antioxidant packaging films from polyvinyl alcohol-corn starch and chilgoza pine nut shell extract:...

Chilgoza pine nut shells (CPNS), an underexploited agro-industrial waste, were utilized as a novel antioxidant source for developing active packaging films using polyvinyl alcohol-corn starch (PC). The addition of CPNS extract (CPNSE) reduced film's transparency, solubility (29.53%), and water vapor permeability (23.54%); improved tensile strength, antioxidant capability (83.62% DPPH scavenging activity and 24.95 mg TE/g FRAP activity) and UV-blocking ability compared to PC film. The FTIR revealed hydrogen bonding between matrix and CPNSE, while, XRD analysis showed increased crystallinity with no notable effect on thermal stability of films with addition of CPNSE. The polyphenols release fitted well to Korsmeyer-Peppas's model (R² > 0.95), indicating Fickian diffusion. Furthermore, pine nuts packed in PC-CPNSE films exhibited lower peroxide (40-70% reduction) and TBARS (15-70% reduction) value compared to PC film; highlighting their potential for extending the shelf-life of lipid-rich foods. The multi-criteria performance analysis revealed film with 10% CPNSE as the most suitable.