Valorization of okara by-product for obtaining soluble dietary fibers and their use in biodegradable carboxymethyl cellulose-based film

Author(s)

Scarcella, Jose Vitor ; Lopes, Melina S. ; Silva, Eric Keven ; Andrade, Grazielle S. S.

• Document type: Journal article
• Source: International Journal of Biological Macromolecules; v. 280, p. 13-pg., 2024-10-01.

Abstract

In the face of mounting environmental concerns and the need for sustainable innovation, the use of agroindustrial wastes as raw materials offers a promising pathway. In this context, this study investigated the okara, a by-product of soy processing, as a novel source of soluble dietary fiber for the enrichment of carboxymethyl cellulose (CMC) biodegradable films based on environmental benefits of waste reduction with the creation of renewable packaging alternatives. Okara soluble dietary fiber (OSDF)-enriched CMC film was compared with films made from traditional and innovative soluble dietary fibers, such as pectin, inulin, and beta-glucan. OSDF was obtained through acid hydrolysis at 121 degrees C, achieving a yield of 5.31 % relative to its initial dry weight. All the produced films exhibited a maximum crystallinity of 5 %, as revealed by X-ray diffraction (XRD), indicative of their largely amorphous structure, while scanning electron microscopy (SEM) ensured their uniformity and flawlessness. The CMC film enriched with okara soluble dietary fiber exhibited key properties, such as thickness, water vapor permeability, and thermal stability, comparable to other soluble fibers studied. These characteristics are essential for effective packaging applications. A notable distinction of the OSDFenriched film was its capacity to block UV light, offering protection for light-sensitive items. The solubility tests showed that okara and beta-glucan contributed to films with a higher solubility percentage. Mechanical testing underscored the influence of fiber on tensile strength, with the film enriched with beta-glucan outperforming others at 27.5 MPa. All films showed rapid biodegradation within one week, emphasizing their eco-friendliness and the study alignment with sustainable development objectives in packaging. (AU)

• FAPESP's process: 23/01876-9 - Pulsed electric field: Design of non-thermal processes, functional foods, and biomaterials
• Grantee: Eric Keven Silva
• Support Opportunities: Scholarships in Brazil - Young Researchers