Recent advances in anthocyanin-based films and its application in sustainable intelligent food packaging: A review

In recent years, a large number of studies have focused on the application of functional packaging films containing anthocyanins for food freshness monitoring and preservation. The chemical properties of anthocyanins bestow upon them the pH indication function. Anthocyanins are flavonoids with a variety of biological activities such as reactive oxygen species scavenging ability. Anthocyanin is also a functional additive that can improve the physical and functional properties of packaging films. The focus of this paper therefore is to review the chemical and biological activities of anthocyanins, as well as their effects on the mechanical, optical, water vapor, thermal, antimicrobial, and antioxidant properties of films as packaging materials. The properties of anthocyanin-based films depend mainly on the source and content of the anthocyanins and on the interactions with biopolymers. In addition, suitable preparation methods (casting, electrostatic spinning, 3D printing, dip coating, hot pressing extrusion, nanoparticle embedding) also have a significant effect on the films' properties. Lastly, the paper also discusses the latest applications of anthocyanin-based films in different types of foods (meat, seafood, dairy products, fruits and vegetables). Anthocyanin-based films combined with intelligent technology can not only enable freshness monitoring of food products, but also extend their shelf life. Nevertheless, future research should also consider key points for achieving sustainable production in industry, such as film performance parameters, consumer acceptance, biosafety and toxicological assessment, which are important for the future development of sustainable intelligent packaging systems.