Analysis Of Different Heat Treatment On Characterization And Protein Composition Of Camel Milk Fat Globule Membrane

Milk fat droplets are surrounded by a membrane called milk fat globule membrane(MFGM),which is mainly composed of proteins,phospholipids,amino acids,polysaccharides and various trace elements and has various biological functions.In recent years,understanding the biological functions of milk fat globule membrane proteins at the molecular level has become a hot research topic in this field.In this thesis,four heat treatment methods were used to heat treat camel raw milk by low temperature long time pasteurization(LTLT,65 ? /30 min),high temperature short time pasteurization(HTST,85 ? /15 s),ultra high temperature pasteurization(UP,125 ? /4 s),and ultra high temperature instantaneous sterilization(UHT,135 ? /4 s),from which milk fat globule membrane and milk fat globule membrane proteins were extracted.The structure,basic composition and content of milk fat globule membranes were determined.The proteomic study of several heat-treated camel milk fat globule membrane proteins was carried out using isotope labeling relative and absolute quantification(ITRAQ)techniques to analyze the differences in structural properties and protein composition of fat globule membranes from different heat-treated camel milk,and the results of this thesis are as follows.1.The results of basic composition and particle size morphology of fat globule membranes of camel milk with different heat treatments showed that the fat globule size decreased after LTLT and HTST treatments,while the fat globule size increased after UP and UHT treatments.compared with the original milk,the changes of protein,amino acids,lipids,trace elements and ash polysaccharide contents in camel milk fat globule membranes after LTLT treatment were not significant.2.The proteomic results showed that a total of 1338 differential proteins were localized between heat-treated camel milk fat globule membrane proteins and camel raw milk fat globule membrane proteins.Compared with the original milk,camel milk treated with LTLT had the fewest differential proteins;intergroup clustering showed that LTLT and HTST clustered into one group,and UP and UHT clustered into one group.As the heat treatment temperature increased,there were fewer proteins with multiple subcellular localizations;different heat treatment differential proteins were significantly enriched to complement and coagulation cascade pathways,and the role of complement and coagulation cascade was significantly enhanced after LTLT treatment of camel milk.This paper provides a theoretical basis for understanding the composition of camel milk fat globule membrane and membrane proteins,and provides rationalization suggestions for processing camel milk products,so as to provide reference for better processing of camel milk products to exploit the efficacy of its fat globule membrane proteins.