On improving bioaccessibility and targeted release of curcumin-whey protein complex microparticles in food

Curcumin is a bioactive food component, with poor bioaccessibility due to low water solubility and stability. Spray drying retained and in fact enhanced curcumin-whey protein isolate (WPI) complexation via desolvation, lowering the amount of unbound curcumin to <5% wt after drying, forming microparticles with better water solubility, stability, and bioaccessibility than raw curcumin. The desolvated microparticles encapsulated 3.47 ± 0.05 mg/g curcumin, almost one order of magnitude higher than the un-desolvated sample 0.37 ± 0.03 mg/g. After incorporation into yogurt, the rapid-release formula liberated 87% curcumin, whereas the targeted-release one discharged 44% before entering the simulated intestinal condition. Most of the yogurt sensory properties were not adversely affected, except for colour and curcumin flavour. This study proposed a strategy in which food ingredients containing hydrophobic bioactive small molecules can be incorporated into a food matrix to improve bioaccessibility and targeted release, without affecting their sensory properties.