Chemical and nutritional composition of Pamir yak milk from Xinjiang.

Pamir yak milk is considered to be ideal food for local people, but its nutritional profile has not yet been reported. This study investigated the chemical and nutritional composition of Pamir yak milk, and compared the results with reference composition of goat and cow milk. We found that the Pamir yak milk had higher contents of protein (4.30%), fat (4.63), lactose (5.21%) and total solid (14.84%) than that of goat and cow milk. The predominant amino acids were glutamate (20%), proline (10%), lysine (10%) and leucine (10%), of which the essential amino acids accounted for 48% of the total amino acids. Meanwhile, Pamir yak milk was rich in minerals such as Ca, Fe, Zn and Mg and thiamine (B ), niacin (B ), Pyridoxine (B ) and cobalamin (B ) were higher than those of cow and goat milk. Also, medium-chain fatty acids (C12-C16) exhibited the highest level. However, The α -linolenic acid (C18:3), eicosapentaenoic acid and docosahexaenoic acid were found in yak milk. All of the above-mentioned differences were demonstrated by the fact that the yak milk quality may be affecting by pasture production, animal species and nutritive value of the herbage. Therefore, Pamir yak milk is a promising alternative food that may contribute to human health.