Hydrophobic and UV-proof colorimetric film based on W/O Pickering emulsion for salmon freshness monitoring

Gaseous amines such as trimethylamine and ammonia are characteristic compounds for monitoring the quality of animal foodstuff like salmon meat. However, there is no existing colorimetric film with both hydrophobicity and UV-proof properties for salmon freshness monitoring in humid and light conditions. Addressing this challenge, a new colorimetric film was developed for monitoring salmon freshness by coating W/O Pickering emulsion containing microencapsulated red cabbage anthocyanin solution onto polyvinylidenefluoride film. The W/O Pickering emulsion was obtained using 3-(Trimethoxysilyl)propyl methacrylate modified TiO 2 @SiO 2 as the emulsifier. The ability of UV resistance and preventing anthocyanin from dissolving out of the film were verified by testing the light and water stability of film. The response of the colorimetric film to gaseous amines was investigated, and the performances including selectivity and linear range were evaluated. Based on this, the colorimetric film was successfully employed to monitor the freshness of salmon within 7 days at 4 ℃.