Application of Box-Behnken design with response surface methodology for optimizing oxygen colour indicator for active packaging

Abstract

The present work develops carrageenan-based oxygen colour color: inherit;">indicator strip films using redox dye to improve the mechanical properties and efficiency of the strip in indicating the presence of oxygen. The optimized percentages of carrageenan (0.6-1.0%) as base medium, titanium dioxide (3.2-4.8%) as semiconductor photocatalyst, glycerol (3.6-4.8%) as sacrificial electron donor and methylene blue as redox dye were determined by applying color: inherit;">Box-color: inherit;">Behnken design and response color: inherit;">surface methodology. It aims to achieve optimum film formulation with good mechanical properties and high colour change values after UV-activation compared to original colour. The color: inherit;">indicator strip film formed whitish-light blue colour after activated with ultraviolet (UV) light and turned to original blue colour after exposure to oxygen. FTIR result shows higher peak on spectra curve in the range of 500 to 750 cm-1 and 2850 to 3750 cm-1 proving the disruption of H-bonds between glycerol and carrageenan after the glycerol molecules were oxidized by the photogenerated holes in TiO2. Depending on the ratio of carrageenan, titanium dioxide and glycerol, the optimum formulation that indicates a protrude colour difference (73.9 ± 2.51) with improved tensile properties (3.39 ± 1.76) has the potential to be used as carrageenan-based oxygen color: inherit;">indicator film for active packaging.