Valorization of Agricultural Waste: A Study on Antimicrobial Edible Films from Avocado Seed Starch and Dragon Fruit Peel

Abstract

The growing accumulation of plastic packaging waste and the underutilization of agricultural residues have encouraged the development of biopolymer-based edible films. This study aimed to produce an edible film from avocado seed starch and dragon fruit peel pectin with the addition of red ginger essential oil as a potential antimicrobial agent and to evaluate its physical, mechanical, and organoleptic properties. The films were prepared using the solvent-casting method with starch-to-pectin ratios of 4:1 and 1:4, with or without the addition of 1 mL of red ginger essential oil. The films were characterized using FTIR and evaluated for thickness, tensile strength, elongation, and Young’s modulus. Their application to chicken meat was organoleptically assessed by 10 panelists based on color and aroma during refrigerated storage. FTIR analysis confirmed the presence of characteristic functional groups in the film components, particularly hydroxyl groups, indicating interactions among the constituents. Film thickness ranged from 0.110 to 0.170 mm and complied with the maximum Japanese Industrial Standard limit of 0.25 mm. The film with a starch-to-pectin ratio of 1:4 and red ginger essential oil exhibited the highest tensile strength of 21.53 MPa. However, elongation values of 0.000107–0.000385% indicated that the films were highly brittle and prone to cracking during peeling, wrapping, and storage. The addition of red ginger essential oil produced a stronger aroma, thereby reducing panelist acceptance. The films showed acceptable thickness and good tensile strength, but their flexibility requires further improvement. Antimicrobial effectiveness could not be confirmed because no direct microbiological testing was conducted.