A preliminary investigation into the unsaponifiable fraction of donkey milk: Sterols of animal origin, phytosterols, and tocopherols

Abstract

We investigated the main sterols, phytosterols, and the α-and γ-tocopherol content in donkey milk during the first 2 mo of lactation. Cholesterol was the main sterol in milk (mean ± standard deviation = 0.97 ± 0.443 g/100 g of fat). Lanosterol was the main minor sterol of animal origin, followed by desmosterol (0.003 ± 0.001 and 0.001 ± 0.001 g/100 g of fat, respectively). Of the phytosterols, β-sitosterol was the main sterol of vegetal origin in donkey milk (0.005 ± 0.002 g/100 g of fat), but lower levels of campesterol, brassicasterol, and stigmasterol were also recorded. Mean levels of αand γ-tocopherol were 0.01 ± 0.007 and 0.003 ± 0.001 g/100 g of fat, respectively. We observed no significant changes in sterol or tocopherol content during the first 2 mo of lactation. The presence of lanosterol in donkey milk is of particular interest, because lanosterol is a potential drug and has important physiological effects. The presence of phytosterols, which are considered nutraceutical molecules, enhances the nutritional quality of donkey milk fat for consumers.

Current Knowledge on Functionality and Potential Therapeutic Uses of Donkey Milk

“…Scientific studies aimed at clarifying the composition of DM and the presence of functional compounds have increased over the past years. Until now, investigations have been carried out to highlight potentially bioactive substances, such as polyunsaturated and omega 3 fatty acids [ 6 , 7 ], functional proteins [ 8 , 9 ], vitamins [ 10 , 11 ], polar lipids [ 12 ], phytosterols [ 13 ], and the milk compositional variability [ 14 , 15 ].…”