Self-assembling of flavonoids and food-approved coformers: an emerging strategy for food preservation and controlled release of eco-friendly preservatives

This review aims to provide a broad but detailed overview on cocrystal formulation involving flavonoids and food-grade coformers and its impact on modulating the physicochemical and biological properties of the parent flavonoid. We will briefly describe cocrystallization, the coformers, the main interactions, methods of production and characterization and the main physicochemical properties (stability, solubility, etc.) that are improved upon their formation. Some examples of flavonoid-based cocrystals, discussion on food preservation strategies based on cocrystals and potential applications are included. Flavonoids are natural compounds used as food ingredients and supplements, with anti-cancer, anti-inflammatory, and antioxidant properties. They are increasingly used in functional foods to improve human health and well-being, but their drawbacks, related to their poor water solubility and limited availability, restricts applications. An effective strategy to improve their functionalities is based on their transformation into molecular complexes (cocrystals) stabilized by non-covalent interactions, which impart new physicochemical properties to the cocrystal components. The combined properties of flavonoid-based cocrystals open up potential applications in food, biological, pharmaceutical, and medical formulations. Cocrystals, therefore, are opening many new doors in relevant industries showing scope for research and providing researchers and formulators with opportunities of making the difficult (or even the impossible), easier and achievable.