Development of egg yolk lipoprotein hydrolysate for nano-delivery of curcumin: Structure-function relationship

Curcumin is a lipophilic polyphenol extracted from the rhizomes of the turmeric plant, exhibiting versatile biological activities. However, its poor solubility, stability, and bioaccessibility present barriers to its effective use in foods or nutraceutical supplements. Egg yolk lipoprotein is a class of natural protein-lecithin composite found in egg yolks with a strong affinity for different hydrophobic active ingredients. In this study, egg yolk lipoprotein hydrolysate was employed to encapsulate hydrophobic curcumin, thereby increasing its solubility, stability, and bioaccessibility. The resulting curcumin-loaded nanoparticles had an average size of 680.9 nm, a zeta potential of around −30 mV, and an encapsulation rate of up to 68.4 %. The solubility of curcumin in water increased by 80 times while maintaining excellent thermal and storage stability. Fluorescence and infrared spectroscopy analysis demonstrated that the assembly process was driven by hydrophobic interactions and hydrogen bonds. The bioavailability of curcumin in nanoparticles has been improved to 30 %, a tenfold increase. These results suggested that egg yolk lipoprotein hydrolysate, a novel peptide-lecithin complex nanoparticle, can improve the stability and bioavailability of hydrophobic polyphenols.