Sustainable Use of Ilex paraguariensis Waste in Improving Biodegradable Corn Starch Films’ Mechanical, Thermal and Bioactive Properties

• Published in: Journal of polymers and the environment 2020-06, Vol.28 (6), p.1696-1709
• Main Authors: Silveira Hornung, Polyanna, Ávila, Suelen, Apea-Bah, Franklin Brian, Liu, Junya, Lopes Teixeira, Gerson, Hoffmann Ribani, Rosemary, Beta, Trust
• Format: Article
• Language: English
• Subjects: Antioxidants; Bioactive compounds; Biodegradability; Biodegradation; Biological activity; Byproducts; Chemistry; Chemistry and Materials Science; Elongated structure; Environmental Chemistry; Environmental Engineering/Biotechnology; Flavonoids; Freshness; Fruits; Glass transition temperature; Ilex paraguariensis; Industrial Chemistry/Chemical Engineering; Light transmission; Materials Science; Melt temperature; Opacity; Original Paper; Packaging; Packaging materials; Permeability; Petroleum residues; Phenolic compounds; Phenols; Physicochemical properties; Polymer Sciences; Scavenging; Starch; Sustainable use; Tensile strength; Thermal properties; Thermodynamic properties; Water vapor
• ISSN: 1566-2543; 1572-8919
• DOI: 10.1007/s10924-020-01723-w

The environmental problems caused by industrial residues and petroleum-based packaging must be addressed, and alternative biodegradable solutions sought. This study investigated the potential application of an industrial byproduct, the fruits of Ilex paraguariensis (yerba mate, YM) polyphenol extracts in the production of environment-friendly and bioactive cornstarch films. Thus, optimized extracts of YM fruits at three different maturity stages (ripe, mid-ripe, unripe) were incorporated into cornstarch filmogenic solutions. Polyphenol extracts were obtained from commercial dried and toasted yerba mate leaves and then incorporated into the filmogenic solutions for comparison. The physicochemical (moisture, thickness, solubility, water vapor permeability, light transmission, opacity, color), structural (crystallinity, surface), mechanical (tensile strength, elongation at break), and thermal (glass transition, melting temperature) properties, in addition to bioactive compounds (total phenolic content, total flavonoid content) and antioxidant activity (ABTS, DPPH, FRAP scavenging) of the films were assessed. Results revealed that YM fruit extracts act as plasticizers, particularly those from ripe fruits. The structural, mechanical, and thermal properties demonstrated that biodegradable, bioactive, strong, flexible, and thermally resistant films can be produced from cornstarch impregnated with YM extracts. The physicochemical properties suggested that the YM fruits-cornstarch films may be applied to maintain freshness of products and to prevent light-triggered oxidative deterioration. Additionally, YM fruit extracts were effective in enhancing the antioxidant properties of cornstarch films, proving that this byproduct has the potential for the development of eco-friendly packaging materials. Graphic Abstract