Active biodegradable packaging based on potato starch and purple corn by-products (Zea mays L.) for postharvest preservation of Spondias purpurea

Biodegradable trays were developed by thermoforming using potato starch, lignocellulosic fiber from purple corn cob, and phenolic extracts, evaluating nine formulations under a 3² factorial design. The trays exhibited appropriate structural properties (thickness: 2.56–3.79 mm; density: 0.25–0.96 g/cm³) and variable mechanical properties (Young's modulus: 33.67–92.25 MPa; tensile strength: 0.40–1.24 MPa). FTIR and XRD analyses revealed a semicrystalline structure with intermolecular interactions through hydrogen bonding among the components. The incorporation of phenolic extracts significantly improved antioxidant capacity (35.98 mg TE/g) and thermal stability. Soil biodegradation tests showed zero-order kinetics with rates ranging from 0.39 to 1.82%/day over 42 days. Formulation T6 exhibited the best mechanical properties and antioxidant functionality. Additionally, the physicochemical properties of Spondias purpurea packaged in T6 (4% fiber + 5.00 g/mL phenolic extract) were evaluated and compared with a control tray made of pure potato starch, demonstrating that the fruit maintained its properties for eleven days of storage. This study contributes to the circular economy through the comprehensive valorization of agro-industrial residues, offering a sustainable alternative for active packaging applications. Future research should explore the potential applications of these biodegradable trays for packaging vegetables, bakery products, among others.