An intelligent film based on self-assembly of funoran and Ophiopogon japonicus seed anthocyanins and its application in monitoring protein rich food freshness

This study explored the physicochemical properties of an intelligent film made from funoran as the raw material and added the indicator, Ophiopogon japonicus seed anthocyanins (OA), to prepare the intelligent film using a casting method and investigated its monitoring effect on the fresh degree of the prawn and chicken breast meat. This study utilized Zeta potential, FTIR spectroscopy, XRD, TG analysis, and SEM to characterize the interaction between Funoran and OA molecules. The results showed that OA was electrostatically attracted to Funoran and recombined to form a more complex network structure, which was successfully locked in the film system. The edible Funoran/OA (FOA) intelligent film had a uniform and dense structure and showed remarkable heat resistance below 100 °C. When OA was added, light barrier, water vapor barrier (WVP), elongation at break (EB), and tensile strength (TS) of the intelligent film increased while the oxygen barrier decreased. The OA solution was sensitive to changes in pH, and the FOA intelligent film had a sensitive response to ammonia. To validate the application of the edible FOA intelligent film, this study used the optimal intelligent film to assess the fresh degree of chicken breast meat and prawn. The study found that the pH value, TVB-N, and total bacterial count increased with the storage time of both. Moreover, FOA2 intelligent film had high sensitivity for assessing the fresh degree of chicken breast meat and prawn, as 0.01 g of the intelligent film could detect a color change in chicken breast meat and prawn that were just spoiled. The authors propose an innovative method of creating high pH-sensitive food preservation films.