Study On Fatty Acids Profile Of Special Livestock Milk

Accompanying the rapid development of cow milk industry in China,special livestock milk has been commercialized regionally step by step.However,nutritional properties and peculiarity,especially the fatty acids(FAs)properties of special livestock milk lacks systematically study.A total of 175 raw and UHT milk sample were collected systematically,including raw milk of Mongolian horse(include sour horse milk,i.e.koumiss),yak,goat and bactrian camel,and UHT milk of yak,buffalo and goat,together with raw and UHT milk of Holstein cow for comparative study.FAs of milk fat were determined by gas chromatography,Descriptive statistics and the principal component analysis(PCA)were conducted according to categories variables such as species,raw and UHT milk,brands,raw and sour horse milk.FAs fingerprint/profile of animal milk indicates very strong species specificity,PCA on FAs shows that milk of livestock are clustering in 3D according to their species.Horse milk cluster separates far from four artiodactyls on the factor 1 axis;Bactrian camel milk separates from bovine family on the factor 2 axis,clustering far in other quadrants;Cow and yak are the closest,while goat milk was relatively remote.It is feasible to identify the milk species by fatty acids profile.Species specific FAs were as follow:?-C18:3n3,C18:2n6c,C16:1 and C12:0 dominate in horse milk;C6:0,C8:0 and C10:0 are high in goat milk;C18:0 is major FA in bactrian camel milk;C18:1n9t,C21:0 and C15:0 in yak milk;and C16:0 and C4:0 in cow milk.?-C18:3n3 and C18:2n6c of horse milk are 21.90±9.43 and 7.66±3.49(x±2SD,g/100gfat),95 and 3times higher than that of cow milk.S:M:P of five livestock milk are 1:0.4:0.05 for cow,1:0.4:0.04 for yak,1:0.6:0.8 for horse,1:0.3:0.03 to goat,and 1:0.4:0.06 to bactrian camel.Ratio of PUFA and SFA(P/S)is 0.05 for cow and yak,0.79 for horse,0.03 for goat,and 0.06 to bactrian camel.Ratio of n-6 and n-3 is 11.5 for cow,1.00 for yak,0.36 for horse,2.11 for goat,and 2.72 to bactrian camel.Horse milk in special livestock milk is closest to the recommended ratio of dietary FAs.Raw milk of yak and goat separates from their UHT milk;UHT milk of yak and buffalo clusters are apparently separated by their brands;Four brands of goat UHT milk are grouped into three clusters.Raw and sour horse milk clusters separates obviously,also shows regional separation.These suggest that FAs properties of milk are related to species,processing and brand and geographical origin,and worthy of further and detailed study.