Analysis Of Nutritional Components In Horse Milk And Comparative Study On Marker Components In Different Dairy Products

Objective: To establish and verify the detection methods of various nutrients in dairy products,and to compare and detect different types of milk,different lactation horse milk and different process of producing horse milk powder.And furthermore,to reveal the characteristic nutrients in horse milk,explore the changes of nutrients in horse milk with lactation,and investigate the influence of nutrients in horse milk by different production processes.Methods:(1)A multi-functional milk analysis instrument was used to compare the conventional components(protein,lactose,solid matter,fat,etc.)of freshly collected different lactating horse milk.(2)Established a method for determining the content of vitamin C in dairy products by HPLC and completed the verification;Established a method for determining the content of taurine and 8 free amino acids(serine,glycine,threonine,alanine,valine,isoleucine,leucine,benzene)in dairy products by AccQ·Tag pre-column derivatization-HPLC and completed the verification;Established a method for determining the content of vitamin C in dairy products by HPLC and completed the verification;Established a method for determining the content of four unsaturated fatty acids(linoleic acid,?-linolenic acid,arachidonic acid,docosahexaenoic acid)in dairy products by GC and completed the verification;Established a method for determining the content of total protein and whey protein in dairy products by Coomassie Brilliant Blue method and completed the verification;(3)Used the established method to detect and compare different types of milk,different lactation horse milk and different process of producing horse milk powder.Results:(1)With the delay of lactation,the contents of solid matter,protein,fat and protein all decreased,especially in the 6-month lactation period,the nutrient content decreased significantly.(2)The establishment of four kinds of nutrient detection methods and the methodological verification were carried out.The results showed that the four methods were specific,the standard curve was linear,the precision and repeatability were up to standard,and the sample recovery rate was in line with the standard.(3)The contents of vitamin C,free serine,linoleic acid,?-linolenic acid and whey protein in horse milk were more prominent;In the early stage of lactation,the contents of arachidonic acid,docosahexaenoic acid,and free serine were high;In the middle of lactation,the contents vitamin C,?-linolenic acid,linoleic acid and free alanine were higher;The contents of linoleic acid and taurine in the late lactation were higher;The different production processes had no effect on the components such as taurine,free alanine and docosahexaenoic acid,and had different effects on other components.Conclusion: The detection methods of the four nutrients established in this paper are faster,more convenient,safer,and can accurately detect the contents of four types of nutrients in dairy products,which are suitable for popularization and application;Compared with other milks,vitamin C,free serine,linoleic acid,?-linolenic acid and whey protein in horse milk are prominent in various dairy products,and are unique nutrients in horse milk;The effects of the two horse milk powder processing techniques on the nutrient composition of horse milk are small,but spray drying has a great influence on the two components of LA and LNA.If this method is to be selected,the process parameters should be adjusted.