Controlling lipid nanoemulsion digestion using nanolaminated biopolymer coatings

The influence of nanolaminated biopolymer coatings around lipid droplets on their physical stability and in vitro digestibility by pancreatic lipase was studied. An electrostatic deposition method was used to form primary, secondary and tertiary emulsions containing lipid droplets coated by: 1°, β-lactoglobulin (β-Lg); 2°, β-Lg-alginate; 3°, β-Lg-alginate-chitosan. The influence of pH (3-7), calcium concentration (5 or 20 mM) and oil type (long vs. medium chain triglycerides) on their physical stability and lipid digestibility was examined. Biopolymer layers had little impact on lipid digestion at 5 mM calcium suggesting that they became detached from the droplet surfaces, but they slowed down digestion considerably at 20 mM calcium, suggesting the formation of a calcium alginate gel that restricted lipases access to emulsified lipids. This study has important implications for design of delivery systems to control lipid digestion and release.