The effect of patchouli essential oil concentration on physical, mechanical properties and antibacterial activity of breadfruit (Artocarpus altilis) starch-based biofilms

Abstract Starch-based biofilms offer a biodegradable alternative to conventional plastic packaging; however, their inherent brittleness, hydrophilicity, and limited antimicrobial functionality restrict their applications. In this study, patchouli essential oil (PEO) was incorporated primarily as a natural antibacterial agent into breadfruit starch-based biofilms. In this study, breadfruit starch-based biofilms were developed with the incorporation of PEO at concentrations of 0%, 0.5%, 1%, 1.5% and 2% as a natural antibacterial agent. The purpose of this study is to evaluate the effect of PEO in different concentrations on the physical, mechanical, and antibacterial properties of breadfruit starch-based biofilms. Biofilms incorporated with patchouli oil showed thicker size, higher opacity, lower tensile strength, better flexibility, faster biodegradation, and a more hydrophilic nature than the control. Importantly, antibacterial activity against Escherichia coli and Staphylococcus aureus was observed at ≥ 1.5% oil concentration, with the highest inhibition at 2%. Among all formulations, the film containing 1.5% patchouli oil demonstrated the most balanced performance, maintaining acceptable mechanical properties while providing antibacterial functionality. These findings highlight the potential of breadfruit starch–based biofilms incorporated with essential oil as eco-friendly active packaging materials, particularly for applications requiring biodegradability and antimicrobial activity.