Mechanical and aging performance of natural fiber-reinforced mycelium composites for sustainable packaging

The increasing demand for sustainable and biodegradable alternatives to petroleum-based packaging materials has stimulated growing interest in mycelium-based bio-composites. In the present work, natural fiber-reinforced mycelium composites were developed and evaluated with emphasis on their mechanical performance and aging behavior for packaging applications. Two composite systems Jute/Rice Straw/Mycelium (JF/RS/M) and Jute/Cocopeat/Mycelium (JF/CP/M) were fabricated under controlled growth conditions to investigate the influence of reinforcement type and growth duration on mechanical properties. Compressive and flexural tests were conducted after 15, 25, 35, and 60 days of growth to characterize strength evolution and structural stability. The results indicate a pronounced increase in mechanical performance with increasing mycelial colonization, with peak properties observed at 25 days. Significant enhancements in mechanical performance were observed relative to the initial testing stage, with compressive strength increasing by 50.3% for JF/RS/M and 69.9% for JF/CP/M composites, and flexural strength improving by 68% and 106%, respectively. To assess aging behavior, mycelial growth was terminated after 35 days, and mechanical testing at 60 days confirmed the retention of structural integrity with no significant degradation in strength. The novelty of this study lies in systematically evaluating the influence of mycelial growth duration on the mechanical evolution and aging stability of natural fiber–reinforced mycelium composites, providing insight into their suitability for sustainable packaging applications.