Composition, Structure, and Function of Milk Fat Globules: Thermal and Non-Thermal Processing Effects and Their Implication in Infant Nutrition Requirements

Human milk represents an indispensable nutritional substrate for neonates. Milk fat globules (MFGs) constitute its fundamental structural entities, providing primary metabolic energy and immunomodulatory bioactive constituents. In instances of suboptimal maternal lactogenesis or contraindications to breastfeeding, infant formulae derived from diverse mammalian milks (e.g., bovine, caprine, and camel) serve as nutritional surrogates. Marked variability exists in the composition, structure, and function of MFGs from human milk and these nonhuman milks. Processing treatments are required to achieve microbial inactivation while attaining biofunctional equivalence to human milk. Contemporary processing technologies, however, routinely induce nutrient degradation processes—including protein denaturation and lipid oxidation within MFGs—concurrently compromising structural integrity and substantially diminishing biofunctional capacity. MFG parametric alterations represent critical process efficacy indices. A comprehensive review elucidating the effects of diverse processing methods on the composition, structure, and functional attributes of MFGs is lacking in the current literature. This work aims to (1) comprehensively characterize MFG compositional–structural–functional relationships; (2) conduct a comparative analysis of MFGs from different sources (human, bovine, caprine, and camelid); and (3) provide a mechanistic elucidation of thermal versus non-thermal processing-induced modifications to MFG composition, structure, and functions. These empirical insights bear material significance for deciphering multisource dairy nutrition, optimizing infant developmental outcomes (particularly among preterm cohorts), and establishing evidence-grounded nutritional frameworks.