Development of active and intelligent colorimetric biopolymer indicator: anthocyanin-loaded gelatin-basil seed gum films

Multifunctional active and innovative biopolymer-based indicator films consisting of a blend of gelatin (GEL) and basil seed gum (BSG) with different concentrations of saffron petal extract (SPE) were prepared. The a* and b* color values depended on pH, which highlighted that the SPE could be used as a pH indicator. The results showed the anthocyanin content increased water vapor permeability (WVP), elongation at break (EAB), and thickness up to 5.02 g/s m Pax10(- 10), 111.21%, 102.71 mu m, respectively, of the GEL-BSG indicator films. As expected, the SPE concentration from 0 to 20% (v/v) decreased tensile strength (TS), moisture content, water solubility and transparency to 5.54 MPa, 16.47%, 30.05%, 56.37%, respectively. The surface and cross-sectional microstructures of the indicator films were examined using scanning electron microscopy, while film component interactions were evaluated using Fourier transform infrared spectroscopy. The incorporation of SPE significantly increased the antibacterial and antioxidant activity of the GEL-BSG indicator films compared to the control film, mainly attributed to an increase in the total phenolic content. In their application experiment, the GEL-BSG indicator film was used as a label to monitor the freshness of fish maintained at 4 degrees C, and the results showed that the film's color changed from red to yellow when the fish deteriorated. Our results suggest that SPE-loaded biopolymer films could be used to monitor and prevent food spoilage simultaneously.

Automated summary

Multifunctional and innovative biopolymer-based indicator films containing gelatin and basil seed gum, with different concentrations of saffron petal extract, were prepared. The addition of saffron petal extract improved the physical properties and antimicrobial activity of the indicator films, making them potential indicators for monitoring food spoilage.