Preparation and study of digestion behavior of lactoferrin-sodium alginate complex coacervates

Complex coacervates of bovine lactoferrin (LF) and sodium alginate (NaAlg) were prepared aiming to protect the structure and associated function of LF in gastric stage of digestion. The parameters affecting the formation of complex coacervates (pH, LF-to-NaAlg ratio) were optimized using electrostatic charge density, turbidity and yield of the complex coacervates. The breaking down of LF structure into smaller peptides, antioxidant capacity and iron release/binding properties of LF and LF-NaAlg were determined in oral, gastric and intestinal stages of in-vitro digestion. The highest yield of LF-NaAlg complex coacervates was achieved at pH 4.5 and the LF-to-NaAlg ratio of 8:1. UP to 30% LF was delivered to the intestinal stage in complex coacervate form while the entire uncomplexed LF was degraded at the gastric stage. The antioxidant capacity of LF in complex coacervate was increased by 12%. The iron binding/release property of LF was not affected in LF-NaAlg complex coacervates.