An aerogel-based intelligent active packaging with the dual functions of spoilage detection and freshness preservation

Due to the highly porous (≈ 96%), lower density (50.71±2.07 mg/cm3) structure of aerogels, which gives them excellent adsorption and release of substances. Furthermore, aerogel-based intelligent, active food packaging may have higher sensitivity than film-based packaging, thus arousing the interest of researchers. In this study, an aerogel was prepared from gelatin, gum Arabic, curcumin, and nisin (GG-cur@Nisin) to achieve the dual functions of spoilage detection and freshness preservation. Scanning electron microscopy observations verified that an interpenetrating polymer network was formed in GG-cur@Nisin. Infrared spectroscopy and X-ray diffraction showed that curcumin and nisin were physically embedded in the aerogel matrix and that van der Waals forces were the main intermolecular interactions. The GG-cur@Nisin aerogels displayed lower density (50.71 ± 2.07 mg/cm3), higher water vapor absorption capacity (0.20 g/g), and lower solubility than films of identical composition. The water contact angle results also showed that the aerogels (90.3° ∼ 92.7°) have more hydrophobic surfaces than the films (51.5° ∼ 61.1°). The GG-cur@Nisin aerogel performed better than the corresponding film in the colorimetric response to 2500 ppm ammonia solution and displayed a sensitive color change to spoilage in shrimp and pork. When used as padding material, the GG-cur@Nisin aerogel can extend the shelf life of pork at 25 °C by up to 6 h. Therefore, the aerogels developed in this study have great potential to ensure food quality and inspire new ideas for intelligent, active packaging.