Recent advances in colloidal delivery systems for nutraceuticals: A case study - Delivery by Design of curcumin

Curcumin is a polyphenolic compound found in turmeric (Curcuma longa) rhizome that has potential biological benefits, including antioxidant, antimicrobial, anti-inflammatory, and anti-cancer activity. Incorporation of curcumin into functional food and beverage products, however, is challenging due to its low water-solubility, poor chemical stability, rapid metabolism, and low oral bioavailability. Researchers are, therefore developing a suite of particle-based delivery systems to maximize the potential health benefits of curcumin. Colloidal delivery systems, such as micelles, microemulsions, nanoemulsions, emulsions, solid lipid nanoparticles, nanostructured lipid carriers, biopolymer nanoparticles, and microgels have all been developed for this purpose. The functional performance of each of these delivery systems depends on its structure and physicochemical properties, such as particle composition, particle size, morphology, physicochemical stability, optical properties, rheology, and sensory attributes. As a result, each delivery system has its advantages and disadvantages for particular applications. Consequently, a delivery system must be specifically designed for the particular bioactive agent to be encapsulated, as well as the particular food matrix it will be incorporated into. In this review, we highlight the potential of the Delivery by Design (DbD) approach for identifying and selecting the most appropriate colloidal delivery system for a particular food application, using curcumin as a model bioactive agent.