Incorporation of norbixin in biodegradable alginate films crosslinked with Ca2+: Pro‐oxidant action

Abstract Alginate is a biopolymer with film‐forming properties that can be used as food packaging material. Norbixin is a carotenoid with antioxidant properties, commonly used as a natural food coloring. The research objective was to create calcium‐crosslinked alginate films and incorporated with norbixin concentrations (N%) of 0.05%, 0.10%, and 0.50% (g norbixin/g alginate). The polymer matrix helped to retard the thermal degradation of norbixin during the drying process and decreased leaching losses during the crosslinking process. The addition of norbixin influenced film opacity in ultraviolet light (all N%) and visible light (higher N%), causing an increase in red‐yellow coloration. Only the higher N% influenced the water vapor permeability of film. Norbixin thus improved the overall barrier properties of the crosslinked sodium alginate film, with a 0.50 N% showing the most promising results. When used as sunflower oil packaging, films with a N% above 0.10 provided pro‐oxidant activity during storage.