Isolation and Characterization of Biodegradable Chitosan Films from Black Soldier Fly Spent Pupal Shells for Food Packaging Applications

Abstract

In response to increasing global demand for sustainable packaging alternatives, this study investigates the feasibility of producing biodegradable chitosan films from Black Soldier Fly (BSF) spent pupal shells for food packaging applications. The purpose of this study is to extract chitin from BSF spent pupal waste, convert it into chitosan films for physicochemical, mechanical, and structural characterization. Chitin was isolated through sequential demineralization, deproteinization, and decolourization, followed by chemical deacetylation to produce chitosan with a high yield (53.48 ± 1.46%) and degree of deacetylation (92.69 ± 0.44%). The resulting BSF-based chitosan films were evaluated for solubility, moisture content, water vapor permeability, tensile strength, elongation at break, and Young’s modulus. While BSF-chitosan films demonstrated good solubility and has moderate barrier properties, it has lower mechanical strength than commercial chitosan films. Through the comparative analysis, the BSF-based films are the thinnest (0.063 ± 0.010 mm), opaquest (3.432 ± 0.018%), highly soluble (42.4 ± 1.47%), has modest moisture content (4.88 ± 4.58%) and low water permeability properties (0.24 ± 0.23 (×10-10 g/Pa∙s∙m)). However, blending BSF and commercial chitosan significantly enhanced tensile properties and film uniformity. FTIR and XRD analyses confirmed characteristic functional groups and crystalline structures suitable for packaging applications. The presence of multiple functional groups (hydroxyl, amine, and alcohol) and a high crystallinity index (≥85%) are expected to enhance the films’ barrier performance and mechanical strength. These findings highlight the potential of BSF spent pupal shell-based chitosan as a sustainable and effective material for biodegradable food packaging, offering a viable alternative to conventional plastics and contributing to reduce plastic pollution.