Development of ovalbumin-pectin nanocomplexes for vitamin D_3 encapsulation: Enhanced storage stability and sustained release in simulated gastrointestinal digestion

摘要

Vitamin D-3 (VD3) is a fat-soluble vitamin and easily degraded under acidic conditions, which will greatly reduce its bioavailability. The use of complexes formed by protein-polysaccharide to control release and protect active compounds has become a feasible way in the food field. In this work, ovalbumin (OVA) and high methoxyl pectin (PEC) were applied to fabricate OVA-PEC nanocomplexes to encapsulate and protect VD3. The encapsulation efficiency of VD3 by OVA-PEC complexes could reach to 96.37%, and the storage stability of VD3 was obviously improved after encapsulation. The in vitro simulated gastrointestinal experiments combined with SEM and SDSPAGE were employed to observe the digestive behavior of OVA-PEC-VD3 nanocomplexes. A small amount of VD3 is released from OVA-PEC-VD3 nanocomplexes in simulated gastric fluid, while a large amount of VD3 is released in simulated intestinal fluid. The sustained release kinetic of VD3 from OVA-PEC-VD3 nanocomplexes was consistent with the law of Higuchi model. The preliminary molecular mechanism for VD3 encapsulation by OVAPEC complexes was also investigated, and the formation of OVA-PEC-VD3 nanocomplexes is ascribed to the electrostatic interactions, hydrogen bonding and hydrophobic interactions among OVA, PEC and VD3. The results demonstrated that protein-polysaccharide complexes can effectively encapsulate VD3 and achieve the goal of sustained release in the simulated gastrointestinal tract, which have potential applications in food and medicine.