Formulation and characterisation of a biodegradable/ edible gelatin based film enhanced with essential oils

Abstract

Plastic trash accumulation and biodiversity loss are just two of the serious environmental issues brought on by the world's reliance on petroleum-based plastics for food packaging. In response, this study aimed to formulate and characterize an edible gelatin-based film enhanced with carboxymethyl cellulose (CMC), cinnamon essential oil, rosemary extract, and food-grade glycerin, evaluating its potential as a biodegradable packaging solution. The film was prepared using a simple casting method and assessed for key functional properties, including thickness, mechanical strength (tensile strength, elongation at break, and Young’s modulus), water solubility, and antimicrobial activity against Escherichia coli and Staphylococcus aureus. Results showed variability in film thickness (0.07–0.12 mm), attributed to uneven casting volumes, which also influenced mechanical behavior. The film exhibited a moderate contact angle of 76.48°, indicating good surface wettability suitable for food coating applications. Thicker films demonstrated higher tensile strength and elongation, suggesting enhanced resistance to tearing. The film exhibited moderate solubility, indicating potential use in moisture-sensitive packaging applications. Strong antimicrobial activity was observed, with inhibition zones of 25–30 mm, validating the functional contribution of the incorporated natural extracts. These findings support the potential of gelatin-based films as environmentally friendly alternatives to synthetic plastics, offering both protective and active functionalities in food preservation. However, standardization of film formulation and broader microbial testing are recommended for future research to optimize and validate the film’s performance in real-world applications.