Model infant formulas: Influence of types of whey proteins and lipid composition on the in vitro static digestion behavior

This work aimed at evaluating the influence of types of whey proteins (lactoferrin, whey protein isolate and/or whey protein hydrolysates) and lipid composition (high oleic sunflower oil, coconut oil and/or medium chain triacylglycerols) on the behavior of model infant formulas (IFs) under simulated conditions of the infant gastrointestinal tract using an in vitro static digestion model. The physicochemical conditions of the gastric medium resulted in the aggregation of oil the droplets and partial hydrolysis of the proteins, considering whey proteins were resistant to the gastric conditions. However, after intestinal digestion the proteins from all the IFs were extensively hydrolyzed. The lipid composition of the IFs did not influence the protein hydrolysis, but the protein composition of the IFs altered the release of free fatty acids. The presence of lactoferrin in the IFs resulted in a higher free fatty acids release compared to IFs of same lipid composition. In terms of lipid composition, IFs containing coconut oil and medium chain triacylglycerols showed extremely higher free fatty acids release than those containing only long chain triacylglycerols. These results are promising for the design of infant foods containing fast-absorbing functional ingredients.