Sugar kelp Saccharina latissima extract as an innovative ingredient for chitosan films: Case study as cheese slice separators

Chitosan films enriched with aqueous extract of Sugar kelp Saccharina latissima (SLE) were developed and characterized by measuring the equilibrium moisture, moisture content, water vapor permeability, mechanical properties, antioxidant properties, optical properties, surface morphology and thermostability. The developed films were tested as separators with antioxidant properties for sliced Havarti cheese. The addition of SLE showed a decrease in mechanical properties such as tensile strength from 48.99 to 36.16 MPa and Young's Modulus from 929.49 to 743.71 MPa compared with pure chitosan films. The resulting chitosan-SLE films showed a high free-radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+). Moreover, the presence of SLE in the chitosan matrix significantly improved the UV-barrier of the samples. When the chitosan-SLE films were employed as separators for cheese, a significant reduction of 52.8% in cheese lipid oxidation was observed after 45 days of refrigerated storage compared to the control group using chitosan films. Hence, an environmentally sustainable alternative to synthetic and non-biodegradable slice separators has been successfully developed using chitosan, a by-product of the fishing industry, fortified with an extract from sugar kelp, a commonly found brown algae.