Recent Advances in Intelligent Food Packaging Applications Using Natural Food Colorants

This review covers the latest research done in biopolymer-based pH-responsive color indicators integrated with natural colorants for real-time monitoring of packaged food quality. The pH-dependent color change of various natural food colorants and the structural change of colorants at different pH values were described. Recent developments in the fabrication of pH-responsive color indicator films prepared by immobilizing natural food colorants obtained from various plant sources into different biopolymer substrates are discussed. Their applications on different food types, including meat, seafood, and dairy products, have been reviewed. They show clear and noticeable color changes with variation in the pH of the food that indicates the degree of deterioration over time. Subsequently, besides the problems faced by natural food color-based indicators, the discussion of commercial pH indicators has also been highlighted.