Development of biopolymer-based gelatin and casein films incorporating brown seaweed Ascophyllum nodosum extract

Abstract

Brown seaweed Ascophyllum nodosum is a rich source of phenolic compounds with antioxidant and antimicrobial properties. The aim of this work was to investigate the effect of incorporation of A. nodosum extract on the physico-chemical and antioxidant properties of gelatin and sodium caseinate films. Gelatin and sodium caseinate films were casted with incorporation of A. nodosum extract at 25 and 50% (w/w of base material) with glycerol added as a plasticizer. The total phenolic content and antioxidant activity of the films increased at higher levels of seaweed extract incorporation. Film properties including thickness, color and light transparency were evaluated. Film appearance was slightly modified and film microstructure analysis highlighted rough surfaces with incorporation of seaweed extract. Hydrophilicity and glass transition temperature of the films also increased at higher levels of seaweed extract. This study demonstrates that seaweed extract can be incorporated in gelatin and casein films as an active ingredient for the development of biofunctional films.