Influence of Dairy Emulsifier Type and Lipid Droplet Size on Gastrointestinal Fate of Model Emulsions: In Vitro Digestion Study

Human breast milk is a natural emulsion containing relatively large triacylglycerol droplets coated by a distinct interfacial layer known as the milk fat globule membrane (MFGM). The unique properties of the MFGM impact the release of nutrients from breast milk in an infant’s gastrointestinal tract (GIT), but the membrane architecture is susceptible to disruption by industrial processes. To formulate infant formula that simulates the gastrointestinal behavior of breast milk, food manufacturers require knowledge of the impact of the interfacial properties on the gastrointestinal fate of fat globules. In this study, a simulated GIT was utilized to monitor the gastrointestinal fate of emulsified corn oil with different dairy emulsifiers, including sodium caseinate, lactoferrin (LF), whey protein isolate (WPI), and milk phospholipids (MPL) isolated from MFGM. The influence of droplet size on the gastrointestinal fate of the MPL-stabilized emulsions was also examined. Our findings provide valuable information for the optimization of infant formula and dairy-based nutritional beverages.