Chemical treatment and characterization of soybean straw and soybean protein isolate/straw composite films

Author(s)

Martelli-Tosi, Milena ; Assis, Odilio B. G. ; Silva, Natalia C. ; Esposto, Bruno S. ; Martins, Maria Alice ; Tapia-Blacido, Delia R.

• Document type: Journal article
• Source: Carbohydrate Polymers; v. 157, p. 512-520, FEB 10 2017.
• Web of Science Citations: 27

Abstract

This work investigated changes in the chemical composition and structure of soybean straw (SS) treated with alkali (NaOH 5% and 17.5%) and bleached with hydrogen peroxide (H2O2) or sodium hypochlorite (NaOCl). Removal of the amorphous constituents increased the degree of crystallinity and the content of cellulose fibers particularly after reaction with high concentrations of alkali. Treatment with NaOH 17.5% contributed to the allomorph transition from cellulose I to II regardless of the bleaching agent, but H2O2 as bleaching agent promoted more effective delignification. This work also evaluated the potential use of treated and non-treated SS as reinforcement filler in soy protein isolate film (SPI). Films added with treated SS presented higher mechanical resistance, lower elongation at break, and lower solubility in water. Addition of non-treated SS did not affect the properties of the SPI film significantly. The low solubility and the reasonable water vapor permeability of the composite films make them suitable packaging materials for fresh fruit and vegetables. (C) 2016 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 12/22154-7 - Isolation of cellulose nanofibers from soybean by-products and their applicability as reinforcement material in biodegradable films
• Grantee: Milena Martelli Tosi
• Support Opportunities: Scholarships in Brazil - Post-Doctoral