The milk fat globules: unique biological systems with a specific composition and multiscale organisation of lipids

Increasing knowledge about the composition and biophysical properties of milk lipids is essential to better understand, modulate and control their properties in food products, to developinnovative functional foods but also to tailor specific lipid structures able to provide nutritional and health benefits. Milk lipids are an important source of energy and bioactive molecules for the optimal growth and development of breast-fed newborns. They are also involved in the functional properties and sensory quality of many dairy products that are consumed by adults[1]. Milk is a natural O/W emulsion in whichfat globules are highly complex and unique entities as regard to the wide diversity of lipid molecules (98% triacylglycerols withmore than 400 fatty acids characterized byvarious chain length and saturation; polar lipidscontaining 30% sphingomyelin, cholesterol) and the multiscale organization of lipids (mean diameter of fat globules 4 µm; crystals of TAG; trilayer of polar lipids in the biological membrane).The structure of milk lipids, both TAG and polar lipids, is affected by temperature and thermal kinetics that induce phase transitions. Dairy processingalso have a major impact on the structure of milk lipids, with consequences on their reactivity in complex dairy products, mainly interactions with milk proteins[1].Thelecturewill provide an overview of the specificities of milk fat globules in terms of composition, structure and functions.Moreover, the recent advances about the structure of the milk fat globule membrane including the dynamics of the lipid domainsrich in sphingomyelin and cholesterol that are responsible for topographical and mechanical heterogeneities will be presented [2,3,4]. The development of processed emulsion droplets bio-inspired by milk fat globules to improve the structure of lipids in infant formulas and narrow the gap with human milk will also be described [5].These recent and new findingswill undoubtadelyopen perspectives in dairy technology and human nutrition(infants and adults).