Impact of interfacial composition on physical stability and in vitro lipase digestibility of triacylglycerol oil droplets coated with lactoferrin and/or caseinate.

The physicochemical and functional properties of oil-in-water emulsions can be controlled by engineering the interfacial layer coating the oil droplets. This study examined the impact of interfacial deposition of lactoferrin (LF) and/or caseinate (Cas) onto oil droplets stabilized by the opposite protein on emulsion stability and lipase digestibility. Zeta potential measurements show both proteins can be deposited on droplet surfaces coated with the opposite protein. Secondary emulsion formulations containing droplets coated with mixed caseinate-lactoferrin layers (Cas-LF and LF-Cas emulsions) had enhanced stability to flocculation in 3 < pH < 7 and from 0 to 80 mM calcium chloride. The majority of emulsions studied were rapidly digested by lipase in an in vitro digestion model, demonstrating the improved secondary formulations are not expected to alter lipid bioavailability. This work provides information valuable in the design of emulsion formulations for applications in the food, pharmaceutical, and personal care industries.