Effect of curcumin, betanin and anthocyanin containing colourants addition on gelatin films properties for intelligent films development

About 52 Mt of food waste is generated annually at the household level. Almost a quarter of this waste is related to packaging issues such as inaccurate data labelling systems. This shows the crucial need to replace or improve food data labels in order to reduce food waste. Gelatin films with different concentrations of curcumin, betanin and anthocyanin containing colourants were prepared by casting. The effect of different concentrations of colourants on the optical, barrier, physicochemical, structural and colour response properties of films was investigated. The addition of colourants altered the colour, light barrier, and wettability of the films. Although the colourant retention capacity of films varied as a function of colourant type, no changes were observed in infrared spectra, and likewise the similar results were obtained by X-ray diffraction, mechanical testing and scanning electron microscopy pointed to retention of tertiary and inner structural properties of the films. The addition of colourants provided films with the capacity to sense pH changes before and after immersion in a fatty food simulant. These properties establish the suitability of the films for intelligent fatty food packaging applications.