High sensitivity intelligent packaging films harnessing rose anthocyanins and hydrophilic silica aerogel for visually food freshness monitoring

Abstract The enhancement of the sensitivity for anthocyanin-based indicator films in food freshness monitoring in real time is important for application. In this study, hydrophilic silica aerogel (SiO2NA) was incorporated into corn starch (CS)/chitosan (CH)/rose anthocyanins (RACNs)-encapsulated potato amylopectin nanoparticles (APNPs) composite film to increase the sensitivity for shrimp freshness detection. Microstructure of films revealed that the gas absorption capacity was improved by amorphous SiO2NA via hydrogen interactions. The pore size (1.74-5.60 times), pore volume (3.92-5.60 times), and specific surface area (2.21-2.34 times) of films increased with the addition of SiO2NA. The sensing to NH3 and pH, and reversibility of films were also reinforced. Meanwhile, the pH-responsible films containing SiO2NA changed visibly in color from purple-red to orange-gray and finally to grey, enabling an effective monitoring of shrimp freshness during storage at 4℃. Thus, anthocyanin-based indicator films with improved sensitivity by adding SiO2NA were successfully designed for monitoring shrimp freshness.