Antibacterial Enhancement of Alginate Edible Films by Incorporation of Green Betel Leaf Extract

Abstract

Alginate-based edible films are increasingly developed not only as biodegradable packaging materials but also as active systems capable of improving food safety through antibacterial properties. The incorporation of natural antimicrobial agents, such as green betel leaf (Piper betle) extract, offers potential to enhance their functional performance. This study aimed to determine the optimal concentration of green betel leaf extract in alginate-based antibacterial edible films. Alginate was extracted from Sargassum sp., and films were prepared using a single-factor Completely Randomized Design with four extract concentrations: 0%, 2%, 3%, and 4%. The films were evaluated for moisture content, water solubility, thickness, elongation at break, tensile strength, water vapor transmission rate (WVTR), opacity, color, surface morphology using Scanning Electron Microscopy, and antibacterial activity. Incorporation of green betel leaf extract significantly affected most physical and functional properties, including moisture content, solubility, mechanical strength, barrier characteristics, optical properties, and microstructure. All films containing the extract demonstrated antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella enterica, and Pseudomonas aeruginosa. The best overall performance, balancing physical integrity and antibacterial effectiveness, was achieved at 4% extract concentration. At this level, the film exhibited 17.72 ± 0.28% moisture content, 29.03 ± 0.60% solubility, 2.50 ± 0.76 MPa tensile strength, 12.77 ± 4.21% elongation at break, 0.090 ± 0.008 mm thickness, 2472.95 g/m2·24 h WVTR, 16.50 ± 8.91% opacity, and 64.69 ± 0.30 color difference (∆E*).