Development and characterization of locust bean gum-Viola anthocyanin-graphene oxide ternary nanocomposite as an efficient pH indicator for food packaging application

The goal of this work was to introduce an eco-friendly pH-sensitive indicator for monitoring food freshness. In this regard, pH-sensitive locust bean gum (LBG) film containing 5 wt % of the extracted anthocyanin from Viola (VE) was fabricated. Subsequently, synthesized graphene oxide (GO) at the optimum concentration (0.5 wt %) was added to the film’s formulation. It was revealed that incorporating GO into the neat LBG and LBG/VE films significantly enhanced the mechanical properties and thermal stability of the film (p<0.05). The LBG/VE/GO film showed a superior moisture content, water solubility, surface hydrophilicity and biosafety than LBG/VE film. The release study demonstrated a controlled release of VE from LBG/VE and LBG/VE/GO films over a period of 48 h. The antioxidant activity of LBG film significantly improved with the incorporation of VE (p<0.05). Overall, LBG/VE/GO film can be introduced as a smart packaging system to monitor the freshness of meat in real-time.