Active and Intelligent Cellulose Acetate Films Incorporating Clitoria ternatea Flower Powder and Extract

ABSTRACT

The demand for active intelligent packaging has been increasing as a strategy to ensure food safety and quality. In this study, cellulose acetate films were developed by incorporating Clitoria ternatea flower powder and freeze‐dried extract at 20% and 30% (w/w). The films were prepared by the casting and were characterized for their appearance, morphology, thickness, antioxidant activity, solubility, moisture content, mechanical properties, water vapor permeability (WPV), color changes, Fourier‐transform infrared spectroscopy (FTIR), and antimicrobiological activity. Analysis visually showed semi‐transparent and rigid structures with visible solid particles and increased thickness. The films exhibited strong antioxidant activity against ABTS (36%–38%) and DPPH (32%–36%) radicals, combined with very low water solubility (0.09%–0.12%), which is desirable for direct contact with food because the material is nontoxic. Colorimetric evaluation revealed pH‐dependent color shifts in both the powder and extract, suggesting their usefulness as natural indicators. Importantly, microbiological tests demonstrated that exposure to Gram‐negative bacteria, including Salmonella Typhimurium and Escherichia coli , caused a distinct color change from purple to green, effectively signaling contamination. The results demonstrate that these biodegradable films have great potential as sensitive indicators of microbiological changes, offering a promising approach for active and intelligent food packaging applications.