Optical and pH-Responsive Nanocomposite Film for Food Packaging Application

In this study, a biocompatible and non-toxic pH-responsive composite film was prepared for food packaging application. The films are composed from polyvinyl alcohol as the main polymeric matrix, nanoclay as a reinforcing component and red cabbage extract as a non-toxic indicator. The prepared films showed lower water uptake values when the amount of nanoclay was increase up to 25 %. It was observed that the films become brittle at high loading of nanoclay (40%). The prepared films exhibited color change in alkaline and acidic medium due to the presence of red cabbage extract which turned pinkish in acidic medium and greenish in alkaline environment. The prepared films were characterized by FTIR and visible spectroscopy. The maximum absorption in acidic medium was (λ_max = 527 nm), while a red-shift occurred in the alkaline medium (λ_max = 614 nm). Future work will focus on crosslinking of the prepared films to improve their mechanical properties.