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

•Chemical treatments increased the cellulose content, crystallinity, and thermal stability of soybean straw.•Alkali treatment produced a mixture of polymorphs of cellulose I and II.•Addition of chemically treated fibers improved the mechanical resistance of SPI film.•H2O2 bleaching provided more eff...

Full description

Saved in:
Bibliographic Details
Published in:Carbohydrate polymers 2017-02, Vol.157, p.512-520
Main Authors: Martelli-Tosi, Milena, Assis, Odílio B.G., Silva, Natália C., Esposto, Bruno S., Martins, Maria Alice, Tapia-Blácido, Delia R.
Format: Article
Language:English
Subjects:
Cellulose
Chemical treatment
Composite films
Food Packaging
Food Preservation
Glycine max
Hydrogen Peroxide
Mechanical properties
Microfiber morphology
Permeability
Sodium Hypochlorite
Soybean Proteins - chemistry
Soybean straw
Structure characterization
Tensile Strength
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•Chemical treatments increased the cellulose content, crystallinity, and thermal stability of soybean straw.•Alkali treatment produced a mixture of polymorphs of cellulose I and II.•Addition of chemically treated fibers improved the mechanical resistance of SPI film.•H2O2 bleaching provided more effective delignification.•Soybean straw treated with H2O2 yielded less soluble composite film. 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.
ISSN:0144-8617
1879-1344
DOI:10.1016/j.carbpol.2016.10.013