Steady-State Solubilization Technologies for and Applications of Hydrophobic Functional Colorants

Hydrophobic functional colorants have garnered significant attention in the development of functional foods due to their bioactive properties, such as antioxidant, anti-inflammatory, and metabolic regulatory effects. However, their low solubility in water and environmental instability severely limit their applications. This paper systematically reviews stabilization and solubilization technologies, including cyclodextrin inclusion, microemulsion solubilization, nanoemulsion, biopolymer nanoparticles, and cocrystals, which can enhance pigment dispersibility and stability by reducing interfacial tension or constructing hydrophobic microenvironments. Studies show that cyclodextrin inclusion, microemulsion solubilization, and nano-delivery systems can significantly improve the solubility and stability of hydrophobic colorants. Cyclodextrin inclusion technology improves the solubility of pigments such as curcumin by several orders of magnitude through host-guest molecular interactions; microemulsion systems effectively inhibit photodegradation of light-sensitive colorants (e.g., lutein); nano-structured lipid carriers provide excellent protection against degradation under high temperatures and long-term storage; cocrystal technology and combined delivery strategies (e.g., reverse micelle microemulsion-cyclodextrin systems) serve the dual functions of solubilization and controlled release. Current research has overcome the limitations of the separate application of various technologies, and multi-technology integration has become an effective pathway to enhance the bioavailability of colorants. Future research should focus on the development of green, low-energy technologies and explore multi-technology integration strategies to promote the widespread application of hydrophobic functional colorants in high-value functional products and sustainable cosmetics.