Recent advances in the preparation, physical and functional properties, and applications of anthocyanins-based active and intelligent packaging films

Anthocyanins are natural colorants with excellent antioxidant, antimicrobial and pH-sensitive properties. In recent years, increasing attention has been paid to the development of active and intelligent packaging films based on biopolymers (e.g. polysaccharides and proteins) and anthocyanins from different plant sources. The structures of anthocyanins-rich films are characterized by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffractometer. The physical properties of the films (e.g. color, thickness, moisture content, water solubility, barrier ability, mechanical properties and thermal stability) are influenced by anthocyanins. Moreover, anthocyanins-rich films exhibit excellent antioxidant, antimicrobial and pH-sensitive properties. In general, the structural, physical and functional properties of anthocyanins-rich films are closely related to the source, composition and content of anthocyanins, the type of biopolymers, and the film preparation and storage conditions. Till now, anthocyanins-rich films have been used to extend the shelf life of food (e.g. oil, cheese and fruits) and to monitor the freshness and quality of protein-rich food products (e.g. fish, shrimp, chicken, pork, milk and cheese). This review summarizes the recent advances in the preparation, structural characterization, physical and functional properties, and potential applications of anthocyanins-rich films in food smart packaging.