Characterization of Edible Coating Formulated from Achi (Brachystegia Eurycoma) Hydrocolloid Incorporated with Ehuru (Monodora Myristica) Essential Oil

Abstract

The development of biodegradable edible films has become a sustainable alternative to synthetic packaging in preserving food quality. This study investigated the physicochemical, mechanical, and structural properties of edible films formulated from Achi (Brachystegia eurycoma) hydrocolloid incorporated with Ehuru (Monodora myristica) essential oil. The films were prepared at different concentrations (1%, 3%, and 5%) using glycerol as a plasticizer. Characterization parameters included film thickness, moisture content, water solubility, swelling power, water vapor permeability (WVP), opacity, tensile strength, elongation at break, and structural analyses using thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). Results revealed that film thickness ranged from 0.059–0.119 mm, moisture content from 12.92–11.53%, and solubility from 31.06–18.86%, indicating improved compactness at higher concentrations. WVP reduced (0.26–0.05 g·mm/m²·kPa·h), demonstrating enhanced barrier properties. Tensile strength increased (9.52–11.50 MPa), and elongation at break ranged between 22.06–34.20%, showing good flexibility. FTIR spectra confirmed interactions between Achi polysaccharides and essential oil functional groups, while SEM revealed smooth, homogeneous surfaces at higher oil concentrations. These findings suggest that Achi hydrocolloid–Ehuru essential oil films possess excellent structural and functional integrity, supporting their potential as natural edible coatings for fresh produce preservation.