Milk lipid in vitro digestibility in wheat, corn and rice starch hydrogels

Starch-based hydrogels or nanoemulsions have been used to regulate lipid digestibility. However, there is a paucity of reports on how starch gels affect milk lipid in vitro digestion. This study compared the pancreatic-lipase-catalysed digestibility of milk lipids in two matrices: milk fat dispersion and milk fat-loaded starch gels. Optical microscopy analysis illustrated that lipid droplets were distributed evenly in starch gels. The peak viscosities of lipid-containing starch gels were higher than those of samples without filled-lipids, whereas final viscosities were reduced with the addition of lipid. Free fatty acid release measurement showed that milk fat embedded in starch gels were two to three times more digestible than dispersed milk fat globules in aqueous phase, as confirmed by a multistep hydrolysis reaction model. This study offers a feasible way to manipulate milk lipid digestibility by stabilisation with starch gels.