Dairy Processing Affects the Gut Digestion and Microecology by Changing the Structure and Composition of Milk Fat Globules

Milk
fat globules (MFGs) are the major source of energy for infants’
dietary intake. In this study, the effects of changes in the structure
and composition of MFG after dairy processing on lipolysis and immune
regulation were investigated. Pasteurized MFG tends to form protein
aggregates to prevent lipolysis. However, the aggregate is rich in
neutrophil degranulation products, which are effective in killing
pathogens. Homogenized MFG has the lowest hydrolysis rate due to the
reconstituted anti-lipase barrier and exposed apolipoprotein. Simultaneously,
the reconstituted barrier can compensate for the lack of the complement
cascade. Spray-dried MFG had the highest hydrolysis rate attributable
to the disrupted MFG barrier and the release of lipoprotein lipase
and endothelial lipase. The immunomodulatory properties of spray-dried
MFG proteins are mainly mediated by the toll-like receptor (TLR) signaling
pathway. This research provides the improvement basis of dairy processing
and functional infant formulas.