Highly ammonia-responsive starch/PVA film with gas absorption system as the 'bridge' for visually spoilage monitoring of animal-derived food.

In the context of food waste and human diseases caused by food pollution, color renderement intelligent packaging came into being. Improving its indicator stability and sensitivity is essential for application. On the basis of our previous work, corn starch/polyvinyl alcohol was used as the matrix, the synthesized zirconium-based UiO-66 and anthocyanin-loaded ovalbumin-carboxymethylcellulose nanocomposites were embedded in to stabilize anthocyanins and improve gas adsorption performance of film. The study found that incorporating appropriate amount of UiO-66 (3%) in films resulted in uniform distribution and formation of holes. Mechanical properties, water stability and barrier properties were significantly improved, and gas adsorption capacity increased by approximately 10 times. More crucially, films that incorporate UiO-66 can react more quickly and visibly to lower concentrations of ammonia gas. The color change of SP/OVA-CMC-ACNs/3% UiO-66 film was noticeable (from purple to gray and then to green) when applied to monitor freshness of shrimp and pork.