Development and comprehensive characterization of sustainable biopolymer films from traditional handpound rice starch

Abstract

Background: The development of sustainable packaging materials from agricultural waste represents a critical approach to addressing environmental challenges posed by conventional plastics. Traditional Handpound Rice (THR) offers unique compositional advantages for bioplastic development due to preservation of beneficial components through minimal processing.

Objective: This study aimed to develop and comprehensively characterize edible biopolymer films from Traditional Handpound Rice starch using solvent casting methodology.

Methods: Bioplastic films were developed through systematic formulation optimization using THR starch, sodium alginate, and glycerol. Six trial formulations were evaluated for film-forming ability, transparency, and handling properties. The optimized formulation was characterized through physical (thickness, density), mechanical (tensile strength), optical (color analysis), spectroscopic (FTIR), thermal (TGA), and microstructural (SEM) analyses. Microbial safety was assessed using Gram staining after six months storage.

Results: Trial 1 formulation (THR starch + sodium alginate + glycerol) demonstrated superior properties with excellent transparency, homogeneity, and flexibility. The optimized films exhibited uniform thickness (0.152 ± 0.018 mm), appropriate density (1.35 g/cm³), adequate tensile strength (11.9 N), and distinctive coloration (L* = 48.92, a* = 16.8, b* = 31.91). FTIR analysis confirmed successful biopolymer matrix formation with characteristic peaks at 3279.83, 2925.56, and 995.66 cm⁻¹. Thermal analysis revealed good stability with maximum degradation at 291.90°C. SEM imaging showed moderately homogeneous structure with crystalline domains. Minimal microbial contamination was observed after extended storage.

Conclusion: Traditional Handpound Rice starch successfully produces high-quality biopolymer films with suitable mechanical, thermal, and optical properties for food packaging applications, representing a viable sustainable alternative to conventional plastics.