182: Optimization of Rice Straw Lignocellulose-Based Biodegradable Films to Extend the Shelf Life of Minced Meat

Introduction

The use of single-use plastic and multiple layers of packaging for food packaging contributes to plastic waste and pollution. Preparing biodegradable packaging from agricultural biomass as an alternative helps to address these critical issues. Utilizing biodegradable biopolymer-based packaging is suitable for perishable goods as the discarded packaging would not pile up. Biodegradable packaging from natural components of agricultural biowaste is superior to chemically synthesized biodegradable polymers as it promotes circularity and reduction of waste. These films can also have more or less similar properties to plastics such as low WVP, barrier properties, tensile strength and elongation, and low water absorption, and thus, they can be utilized in food packaging and preservation.

Methods

Lignocellulose residue from rice straw was extracted. Several formulations of rice lignocellulose films were prepared by solubilizing the cellulosic fraction (0.35-0.65%) in 68% ZnCl2 solution and to crosslink with Ca2+ ions from CaCl2 (200-600mM) to form the network, and glycerol (0.5-1.5%) was added as a plasticizer. Films cast on glass plates were denatured with alcohol and washed with water to remove the adhered salts. Optimization was based on desirable properties of film to have high tensile strength and elongation, and low water vapor permeability. The optimized film was evaluated for color, water solubility, water absorption, hydrophobicity, UV-blocking properties, and soil biodegradability. The optimized film was further used for the analysis of the shelf-stability of minced meat based on color and pH. Excel, Design Expert, and GenstStat were used for statistical analysis and calculation.

Results

The lignocellulose residue yield from the rice straw was 30%. Optimum film formulation, based on Box/Behnken model, was achieved with 0.55 g lignocellulose, 600 mM CaCl2, and 1% glycerol yielding tensile strength (50-70 MPa), elongation (5-6%), and WVP (0.7*10-10g.m-1.h-1.Pa-1). Film biodegrades around 70% in 30 days at 24% soil moisture and preserves minced meat for 7 days compared to control samples without packaging.

Significance

The study aims to valorize agricultural waste into a product that has global demand as well as reduce microplastic pollution and advance the circular bioeconomy through ecological preservation.

Authors: Sharad Bhattarai, Srinivas Janaswamy