ANNATTO CLUSTERS: SUSTAINABLE ALTERNATIVE FOR BIODEGRADABLE PACKAGING

The state of Paraná is the largest producer of annatto in southern Brazil. Annatto seeds develop inside flattened seed pods, which are discarded after seed extraction, generating a substantial amount of agro-industrial waste. These residues have significant potential for value addition, as they represent an abundant source of lignocellulosic compounds suitable for the development of bio-based materials. Traditionally, the processing of fibrous plant biomass involves harsh chemical treatments using concentrated acids and alkalis. However, in accordance with the principles of green chemistry and the circular economy, more sustainable processing methods have gained increasing attention due to their ability to reduce environmental impacts, minimize the use of aggressive chemicals, and decrease waste generation, making them promising alternatives for the valorization of lignocellulosic biomass. The aim of this study was to evaluate the potential use of annatto seed pods (UC) as a source of cellulose derivatives through a low-environmental-impact technological approach. The samples were treated in an autoclave for 30 minutes. Before the extrusion step (110 °C and a screw speed of 150 rpm), hydrogen peroxide solution (200 volumes) equivalent to 10% of the dry mass was added, and the samples were conditioned for 24 hours. After extrusion, the materials were dried at 35 °C for 12 hours. The fiber samples used for film production were: FP (ground annatto seed pods); FPA (ground and autoclaved seed pods); FPAE (ground, autoclaved, and extruded seed pods); and FPE (ground and extruded seed pods). The biodegradable films were prepared by the casting method using 250 mL of distilled water, 5% biodegradable polymer, 30% glycerol, and 5% cellulose derivatives. The resulting films were characterized in terms of their mechanical properties and water vapor permeability. Biodegradable films containing cellulose fibers were successfully produced. However, the incorporation of the fibers negatively affected the mechanical properties, while only minor changes were observed in water vapor permeability.