Due to their inability to biodegrade, petroleum-based plastics pose significant environmental challenges by disrupting aquatic, marine, and terrestrial ecosystems. Additionally, the widespread presence of microplastics and nanoplastics induces serious health risks for humans and animals. These pressing issues create an urgent need for designing and developing eco-friendly, biodegradable, renewable, and non-toxic plastic alternatives. To this end, agro-industrial byproducts such as soyhulls, which contain 29–50% lignocellulosic residue, are handy. This study extracted lignocellulosic residue from soyhulls using alkali treatment, dissolved it in ZnCl₂ solution, and crosslinked it with calcium ions and glycerol to create biodegradable films. The film formulation was optimized using the Box–Behnken design, with response to tensile strength (TS), elongation at break (EB), and water vapor permeability (WVP). The optimized films were further characterized for color, light transmittance, UV-blocking capacity, water absorption, contact angle, and biodegradability. The resulting optimized film demonstrated a tensile strength of 10.4 ± 1.0 MPa, an elongation at break of 9.4 ± 1.8%, and a WVP of 3.5 ± 0.4 × 10⁻¹¹ g·m⁻¹·s⁻¹·Pa⁻¹. Importantly, 90% of the film degrades within 37 days at 24% soil moisture. This outcome underscores the potential of soyhull-derived films as a sustainable, innovative alternative to plastic packaging, contributing to the circular economy and generating additional income for farmers and allied industries.

The extensive use of petroleum-based plastics in food packaging has raised environmental concerns, increasing interest in biodegradable materials derived from renewable resources. Cellulose-based films from agricultural residues offer a sustainable alternative, and incorporating bioactive compounds can provide active packaging functionality to enhance food preservation. In this study, resveratrol was incorporated into oat straw-derived cellulose films to develop biodegradable active packaging materials. Films with varying concentrations of resveratrol were prepared and evaluated for physical, mechanical, barrier, optical, antioxidant, biodegradation, and fruit preservation properties. Resveratrol significantly enhanced the films’ antioxidant activity, increasing radical-scavenging activity from 4.05% in the control film to 19.70% in the film containing 0.7% resveratrol. The films also exhibited improved ultraviolet light-blocking properties while maintaining comparable moisture content, water solubility, mechanical properties, water vapor permeability, and biodegradation behavior. All films showed rapid soil biodegradation, with more than 80% weight loss after 33 days. During grape storage, the resveratrol-containing film maintained the fruit quality by moderating changes in weight loss, total soluble solids, titratable acidity, and ascorbic acid content, while avoiding the quality deterioration observed in polystyrene-covered grapes during storage. These findings demonstrate that oat straw-derived cellulose films containing resveratrol combine antioxidant activity, ultraviolet light protection, biodegradability, and improved preservation performance during grape storage. The developed films show promise as sustainable antioxidant active packaging materials for fresh-produce applications.