Multi-functional pH-sensing/antioxidant/antibacterial bioaerogels with long-term activity of loaded anthocyanin for the smart packaging of food

Anthocyanins (ATH), which are plant pigments with potential health benefits, possess antioxidant and natural indicator properties. However, their inherent instability poses a hurdle for practical applications in the food industry. In the present study, we addressed this challenge by encapsulating ATHs in nisin/gelatin (GA)/pullulan (PUL) bioaerogels through freeze-drying. The results showed that the ATH + nisin@GA/PUL bioaerogels exhibited antibacterial activity against S. aureus and E. coli, and pH-responsiveness to the increase in biogenic amines during the spoilage of shrimp, indicating their potential as a freshness indicator. The bioaerogels also displayed sustained antioxidant effects after two months of storage at room temperature. In summary, the ATH + nisin@GA/PUL bioaerogel serves as a stable matrix for preserving the antioxidant activity of ATHs, and facilitates the indication of freshness in perishable foods. This innovative encapsulation technique represents an advancement in the utilization of ATHs in food packaging.