The influence of MPL addition on structure, interfacial compositions and physicochemical properties on infant formula fat globules.

The lack of milk fat globule membrane phospholipids (MPL) at the interface of infant formula fat globules has an impact on the stability of fat globules, compared to human milk. Therefore, infant formula powders with different MPL contents (0%, 10%, 20%, 40%, 80%, w/w of MPL/whey protein mixture) were prepared, and the effect of interfacial compositions on the stability of globules was investigated. With increasing MPL amount, the particle size distribution had two peaks and returned to a uniform state when 80% MPL was added. At this composition, the MPL at the oil-water interface formed a continuous thin layer. Moreover, the addition of MPL improved the electronegativity and the emulsion stability. In terms of the rheological properties, increasing the concentration of MPL improved the elastic properties of the emulsion and the physical stability of the fat globules, while reducing the aggregation and agglomeration between fat globules. However, the potential for oxidation increased. Based on these results, the interfacial properties and stability on infant formula fat globules was significantly influenced by the level of MPL, which should be considered in the design of infant milk powders.

Interfacial compositions of fat globules modulate structural characteristics and lipolysis of its model emulsions during in-vitro digestion.

BACKGROUND: This study investigated whether milk fat globule membrane as an emulsifier could make fat easier for infants to digest. An emulsion was formed using the membrane material, where anhydrous milk fat was used as the core material, milk fat globule membrane polar lipid (MPL) as the emulsifier, and soybean phospholipid (PL) and milk protein concentrate (MPC) incorporated as control emulsifiers. Structural characterization, glyceride composition, and fatty acid release from emulsions by in vitro digestion were investigated. RESULTS: The average particle size at the end of intestinal digestion was in the order MPL < PL < MPC, with diameters of 3.41 ± 0.51 µm, 3.53 ± 0.47 µm, and 10.46 ± 2.33 µm respectively. Meanwhile, laser scanning confocal microscopy results also illustrated that MPL could reduce the degree of aggregation during digestion. The lipolysis degree of MPL emulsion was higher than that of PL and MPC emulsions. MPL not only released higher levels of long-chain fatty acids, such as C18:1, C18:2, C18:3, which are of great significance for infant growth and development, but also released increased levels of C20:4 (arachidonic acid) and C22:6 (docosahexaenoic acid) than PL and MPC emulsions did. CONCLUSION: Fat droplets enveloped by milk fat globule MPLs were easier to digest and are therefore more suitable for infant formula. © 2023 Society of Chemical Industry.