Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE From tomato sauce waste to sustainable packaging: tomato processing by-products are upcycled as fillers in biodegradable polymers and processed through blown film extrusion to fabricate heavy-duty bags, enabling a circular and value-added use of agri-food residues.

ABSTRACT
The growing environmental impact of conventional packaging highlights the urgent need for sustainable alternatives. This work investigates the development of bio-composite films by incorporating tomato-processing by-products into a commercial biodegradable polymer system. Tomato residues were dried, finely milled, sieved (< 45 and < 90 μm), and incorporated at loadings of 5 and 10 wt% by melt mixing. Increasing filler content and decreasing particle size produced a higher complex viscosity and melt strength (MS), while the break stretching ratio (BSR) decreased. All formulations showed excellent filmability both on laboratory and industrial film-blowing lines, producing homogeneous blown films with a thickness of 100–120 μm. Mechanical tests demonstrated that the bio-composites maintained properties comparable to the neat matrix and to conventional polyethylene (PE) films for heavy bag applications. For instance, the 5 wt% < 45 μm composite showed a tensile strength of 30 MPa and an elongation at break of 705%. Ball-drop impact resistance remained high (580 N/mm). Stable film blowing was successfully achieved also at an industrial scale, confirming the real applicability of the proposed bio-composite formulations for heavy-duty packaging. These results demonstrate that tomato fillers can be upcycled into a biodegradable polymer matrix, offering a viable route for circular-economy heavy-duty packaging.