Morphological, structural, and functional properties of biobased cassava starch foam trays added with turmeric pigment extraction residue

Overview & Synopsis

Adding residues to biobased packages can lower production costs, reduce dependence on petroleum and demand for biopolymers, enhance package properties, and valorize byproducts. Bio-based foam trays were produced from cassava starch and turmeric dye extraction residue (TR). The study investigated the effect of different starch: TR mass ratios (100:0, 90:10, 80:20 and 70:30) on the physical and morphological properties, water resistance and biodegradability of the foam trays. TR addition to cassava starch foam tray, yielded colorful composite foam trays, with shades that varied from whitish to brownish. Increasing TR concentration provided less porous, denser, more water-resistant, and less hydrophilic composite foam trays. Composite foam trays had similar tensile strength (2 MPa), but lower elongation at break and deformation than the Control tray, mainly at high TR concentration. Three-dimensional (3D) analysis by X-ray nano-computed tomography confirmed that TR addition affected the cassava starch foam structure: the solid phase average thickness decreased, and pore morphology changed, to give denser and less porous foam trays. Compared to EPS foam tray, the composite foam trays were less uniform and porous and mechanically stronger, but their maximum elongation until rupture was lower. In contrast to the EPS foam tray, which did not biodegrade, the composite foam trays biodegraded completely within 31 days, while the Control tray biodegraded within 14 days. Overall, the composite foam tray produced with 10 % TR holds considerable potential for being further optimized and commercially employed as a food or non-food container.