In vitro digestibility of heteroaggregated droplets coated with sodium caseinate and lactoferrin

Aggregation of droplets coated with oppositely charged proteins could be affected during emulsion digestion. Thus, emulsions stabilized by sodium caseinate, lactoferrin or heteroaggregated droplets formed from the mixture of both emulsions were evaluated by in vitro digestibility. Emulsions properties were analyzed in terms of stability, microstructure, particle size, surface charge and free fatty acids. Changes in physical properties at the different digestion steps depended on the emulsifier properties and were probably attributed to physico-chemical environment conditions and protein hydrolysis. The heteroaggregates undid in simple emulsions at the gastric phase due to the electrostatic repulsion between the proteins at low pH. Free fatty acids release depended on emulsifier properties, in addition to the presence of bile salts. Heteroaggregates presented the lowest extent of lipid digestion followed by droplets coated with lactoferrin. These results may be useful for the design of food matrices with a decreased digestibility.