**1. Introduction**

Human milk is especially complete and suitable to provide the essential to the infants due to its composition including a variety of nutrients, bioactive compounds and immunological factors, which are indispensable for the newborn growth and optimal development [1]. Moreover, studies have demonstrated the benefits of human milk for newborns concerning gastrointestinal problems, growth, neurological development and immune system [2]. Breastfeeding is recognized as the gold standard for feeding infants and should be the exclusive feed source during the primary 6 months of life, without the demand to supplement with additional food or liquid. Besides, the breastfeeding should be prolonged even after food introduction during the primary 2 years of life [3].

Lipids are allocated in groups according to its solubility in apolar and organic solvents insoluble in water, being classified as neutral lipids: triglycerides (TAG), diglycerides (DAG) and monoglycerides (MAG), polar lipids: phospholipids and glycolipids, and miscellaneous lipids: sterols, carotenoids and vitamins [4].

In human milk, the lipids are present as fat globules form, mainly constituted of TAG surrounded by a structural membrane composed of phospholipids, cholesterol, proteins and glycoproteins [5]. The fat from human milk is its main energy source, consisting 98% (m/m) of neutral lipids (TAG, DAG and MAG) [6]. Hence, the fatty acid composition of these constituents defines the nutritional and physicochemical properties of human milk fat [7].

TAG are molecules of glycerol esterified to three fatty acids (FA), which may be located at the TAG sn-1, sn-2 and sn-3 positions. However, the FA position in TAG is also related to the human milk quality. In TAG from human milk, for example, palmitic acid is positioned normally on sn-2 (the central carbon atom) [8], which facilitates the action of pancreatic lipase. Besides, it leads to improved absorption of fat and calcium by newborns due to the subsequent metabolism of these TAG in the infant's body [9].

Therefore, numerous analytical techniques are employed to attempt the verification of the FA composition as well as TAG structure present in human milk fat. This chapter will address the benefits associated with the consumption of human milk, as well as analytical techniques employed to assess its lipid quality.
