Fabrication and study on alginate-based biodegradable active film incorporated with cuminaldehyde and Zataria multiflora extract liposomes

Abstract

The demand for sustainable food packaging has driven research into biodegradable films with improved functional properties. However, limitations such as poor mechanical strength, high water permeability, and low antioxidant and antibacterial activity restrict their application. This study addresses these issues by developing alginate-based films incorporating Zataria multiflora extract (ZmE) and cuminaldehyde encapsulated in liposomes. The moisture content of films ranged from 7.9 % to 8.37 % with non-significant differences. Thickness and density of films with encapsulated ZmE and cuminaldehyde were 135 μm and 1.35 g/cm^-3, respectively, comparable to the control. Free-form ZmE and cuminaldehyde caused non-uniformity in the film matrix, whereas encapsulation improved structural homogeneity. Liposomal ZmE and cuminaldehyde increased tensile strength (TS) (5.95 MPa) and elongation at break (EAB) (37.08 %) while reducing water vapor permeability (WVP). Lightness (L*), whiteness index (WI), and color difference (ΔE) were affected without changes in opacity. Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) analysis indicated weak biopolymer-additive interactions. Radical scavenging activity (RSA) in liposomal films remained high (75.72 %) after 30 days. Liposome incorporation also enhanced antibacterial activity, particularly against Gram-positive bacteria. These findings suggest that liposomal encapsulation improves the physical, mechanical, and functional properties of alginate films, making them a promising material for active food packaging applications.