A Sustainable Approach to Develop Biodegradable Films: Towards Valorization of Soyhulls — 52p — Sumi Regmi, Srinivas Janaswamy

Department of Dairy and Food Science, South Dakota State University, Brookings, SD 57007, USA

Massive use of non-biodegradable single-use plastic packaging has led to the accumulation of plastic waste in the environment, affecting land, marine, and aquatic life. Plastic particles are severe risk factors for animals’ alimentary canals and human lungs, heart, liver, and placenta. Thus, there is a need for a new generation of packaging materials that are biodegradable, renewable, and sustainable. To this end, lignocellulosic residue from agricultural biomass and agricultural processing byproducts, such as soyhulls, is suitable due to its renewability, sustainability, and contribution to the circular bioeconomy. Herein, the lignocellulosic residue from soyhulls (SLR) was extracted using 20% (w/v) NaOH, solubilized in ZnCl₂ solution, and crosslinked with calcium ions and glycerol to prepare films. The Box Behnken Design was used to optimize the amounts of SLR, calcium ions, and glycerol against responses tensile strength (TS), elongation at break (EB), and water vapor permeability (WVP). The optimized film showed a TS of 16.8(3) MPa, EB 14.7(2)%, and WVP of 0.22(4) x10^-10 gm^-1s^-1Pa^-1. It is translucent with UV-blocking and antioxidant properties and biodegrades within 33 days at 24% soil moisture content. The film extended strawberries’ shelf life by 3 more days compared to polystyrene film while retaining the original color, total soluble solids, ascorbic acid, and total phenolic compound contents. Overall, the value-added soybean hull lignocellulose-based packaging films are advantageous in addressing plastic-related issues and preserving fruits for longer durations.

South Dakota State University
Dr. Srinivas Janaswamy