Evaluating how avocado residue addition affects the properties of cassava starch-based foam trays

Avocado seed (AS) is an interesting residue for biopackaging because it has high starch content (41 %). We have prepared composite foam trays based on cassava starch containing different AS concentrations (0, 5, 10 and 15 % w/w) by thermopressing. Composite foam trays with AS were colorful because this residue contains phenolic compounds. The composite foam trays 10AS and 15AS were thicker (2.1-2.3 mm) and denser (0.8-0.9 g/cm³), but less porous (25.6-35.2 %) than cassava starch foam (Control). High AS concentrations yielded composite foam tray less puncture resistant (∼40.4 N) and less flexible (0.7-0.9 %), but with tensile strength values (2.1 MPa) almost similar to the Control. The composite foam trays were less hydrophilic and more water resistant than control due to the presence of protein, lipid, and fibers and starch with more amylose content in AS. High AS concentration in composite foam tray decreases the temperature of thermal decomposition peak corresponding to starch. At temperatures >320 °C the foam trays with AS were more resistant to the thermal degradation due to the presence of fibers in AS. High AS concentrations delayed the degradation time of the composite foam trays by 15 days.