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

We investigated the main sterols, phytosterols, and the alpha- and gamma-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, P-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 alpha- and gamma-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.

Automated summary

The study investigated the sterol and tocopherol content in donkey milk during the first 2 months of lactation, finding cholesterol to be the main sterol and lanosterol to be of particular interest. The presence of lanosterol and phytosterols in donkey milk enhances its nutrional quality for consumers.