Chitosan/sodium alginate/ethyl cellulose-based multilayer film incorporated with l-ascorbic acid for improved barrier and antioxidant properties

Abstract

A bioactive multilayer film (ML) loaded with l-Ascorbic acid (AA) was developed using chitosan (CH), sodium alginate (SA), and ethyl cellulose (EC). Various properties of the films, including morphological, hydrophobic, barrier, mechanical, optical, and antioxidant characteristics, were evaluated and compared to those of monolayer films made from each biopolymer. The cross-sectional analysis via scanning electron microscopy revealed the successful preparation of the ML film with layering of the different biopolymers. For the ML film the resulting water contact angle was observed with an average of 73.86° and the film showed water resistant properties as compared to the individual CH and SA films. The ML film showed the lowest water vapor transmission rate (WVTR) at 54.99 g·d⁻¹·m⁻² as compared to the individual films. Moreover, the ML film had the highest tensile strength at 0.56 MPa as compared to the mono-layer films including CH, SA, and EC with TS values of 0.33, 0.24 and 0.17 MPa, respectively. Furthermore, the AA-loaded ML film exhibited significantly higher DPPH scavenging activity at 66.20 %. These findings suggest that the ML film, due to its superior barrier, mechanical, and antioxidant properties has the potential for the applications in active food packaging.