Complexation of curcumin with Lepidium sativum protein hydrolysate as a novel curcumin delivery system

The complexation of Lepidium sativum protein hydrolysate (LSPH) with a lipophilic molecule, curcumin (CUR), and its effect on curcumin in vitro bioaccessibility/stability, functional and antioxidant activity were investigated. Fluorescence spectroscopy of the LSPH/CUR complex confirmed the presence of hydrophobic interactions that led to the complex formation. The LSPH (10-30 kDa) fraction showed a compact complexation with curcumin at pH 3.0 with excellent aqueous solubility, stability, and bioaccessibility. Further, complexation enhanced the aqueous solubility of curcumin more than 856-fold. In vitro sequential simulated gastric and intestinal digestion indicated that the bioaccessibility of curcumin was increased from 67% to 95% post complexation. The functional attributes suggest that the LSPH/CUR complex has good foam-forming capacity and emulsion stability, which are crucial for food product formulations. The results indicate that, since LSPH is a dietary protein, it might possibly be formulated as a functional food and as an excellent lipophilic bioactive molecule delivery vehicle in food formulations.