INVITRO MODEL FOR LIPASE-CATALYZED LIPOPHILE RELEASE FROM FATS

A simple method was developed to study the release and dispersion of lipophilic substances into the aqueous phase from an edible oil emulsion and to estimate their potential availability for transport across the intestinal lumen. The rates of cholesterol release and dispersion from butter oil-cholesterol and from butter oil fatty acid based sucrose polyester-cholesterol emulsions were compared when both systems were exposed to lipoprotein lipase or bile-pancreatic fluid, under conditions that simulated in vivo hydrolysis. The cholesterol lipophile remained associated with the oil phase in the butter oil emulsion until appreciable hydrolysis had taken place. Results clearly indicate that cholesterol release is intimately linked to the extent of lipolysis likely via cholesterol entrapment in the micelles as they are formed. No detectable lipolysis took place in experiments with sucrose polyester-cholesterol emulsions and no cholesterol was released. The method provides a facile technique for in vitro measurements of lipophile release, and the results obtained conform to in vivo hypotheses of lipid transfer and absorption.