Thermoformed Fiber-Polyethylene Biocomposites: A Circular Food Packaging on Cherry Tomatoes

Abstract

Current European food packaging legislation requires exploring new alternatives to respond the challenges that lie ahead. Using sustainably sourced biomass, such as pruning residues, has significant potential for creating sustainable packaging. Avocado pruning fiber (10–40%) together with bio-polyethylene was used to produce biocomposites by thermoforming technology. The materials were evaluated for food contact suitability. Adding avocado pruning fiber to biopolyethylene improved processability, producing functional trays with up to 30% fiber. The biocomposites reduced S. aureus and L. monocytogenes adhesion, especially with 20% fiber, and enhanced antioxidant activity, reaching 17.82% SA/cm2 with 40% fiber. Soil degradation tests showed a 23% reduction for 40% fiber samples after 91 days. Migrations within the limits for hydrophilic, acidic, and fatty foods were obtained for samples containing up to 20% fiber. Cherry tomatoes stored in bio-based trays demonstrated comparable or superior preservation to commercial high-density-polyethylene trays, with reduced fungal growth, lower weight loss, and better color retention.