From Waste to Value: Fruit Biofillers in Biodegradable Composite Materials

This study addresses the urgent need for sustainable alternatives to single-use plastics by developing biodegradable composites from peach and apple processing waste employing hot compression molding. Utilizing a definitive screening design, the impact of process variables, including recipe composition, grinding size, pressure, temperature, and holding time, on the physical, mechanical, and water-resistance properties of the composites was systematically evaluated. Physicochemical and thermal analyses of the dried by-products indicated that processing temperatures below 150°C prevent degradation of lignocellulosic constituents. The results demonstrated that increasing both molding pressure and holding time decreased composite thickness, while enhancing stiffness and flexural strength, with modulus of elasticity values exceeding 1000 MPa under optimal conditions. Higher molding temperatures reduced water absorption and diffusivity, particularly in lignin rich composites, by promoting lignin softening and particle consolidation, resulting in denser structures with limited moisture transport. Biodegradability was assessed through soil burial tests over 200 days, revealing a weight loss ranging from 54.2% to 90.7% among samples, with apple-based composites exhibiting greater degradation compared to peach-based ones. Overall, the study highlights the development of a “green composite” formulation where two different in composition biowastes are combined to produce a plastic free composite material with possible applications in food service industry.