scholarly journals Changes in structure of the bovine milk fat globule membrane on heating whole milk

1992 ◽  
Vol 59 (3) ◽  
pp. 321-329 ◽  
Author(s):  
Avis V. Houlihan ◽  
Philippa A. Goddard ◽  
Barry J. Kitchen ◽  
Colin J. Masters

SummaryThe effects of heat-induced interactions between milk fat globule membrane components and skim milk proteins in whole milk on the structure of the membrane were examined by isopycnic sucrose density gradient centrifugation and by using Triton X-100 as a membrane probe. Skim milk components were incorporated into all the lipoprotein fractions separated by density gradient centrifugation. High density complexes, higher in density than those found in the natural milk fat globule membrane, were formed during the heat treatment. Losses of natural membrane polypeptides from the medium and low density lipoproteins were observed on heating. Heating whole milk also altered the rate of release of membrane components by detergent, with decreases in protein released and an increase in phospholipid constituents released. Studies on washed cream indicated that some of the changes in the membrane on heating whole milk occurred due to the heat treatment alone, independent of the interactions with skim milk proteins.

1992 ◽  
Vol 59 (2) ◽  
pp. 187-195 ◽  
Author(s):  
Avis V. Houlihan ◽  
Philippa A. Goddard ◽  
Stephen M. Nottingham ◽  
Barry J. Kitchen ◽  
Colin J. Masters

SummaryHeating raw milk at 80 °C for 2·5–20 min was found to result in compositional changes in the milk fat globule membrane (MFGM). The yield of protein material increased with the duration of heating, owing to incorporation of skim milk proteins, predominantly β-lactoglobulin, into the membrane. Lipid components of the MFGM were also affected, with losses of triacylglycerols on heating.


2002 ◽  
Vol 69 (4) ◽  
pp. 555-567 ◽  
Author(s):  
SUNG JE LEE ◽  
JOHN W. SHERBON

The effects of heat treatment and homogenization of whole milk on chemical changes in the milk fat globule membrane (MFGM) were investigated. Heating at 80 °C for 3–18 min caused an incorporation of whey proteins, especially β-lactoglobulin (β-lg), into MFGM, thus increasing the protein content of the membrane and decreasing the lipid. SDS-PAGE showed that membrane glycoproteins, such as PAS-6 and PAS-7, had disappeared or were weakly stained in the gel due to heating of the milk. Heating also decreased free sulphydryl (SH) groups in the MFGM and increased disulphide (SS) groups, suggesting that incorporation of β-lg might be due to association with membrane proteins via disulphide bonds. In contrast, homogenization caused an adsorption of caseins to the MFGM but no binding of whey proteins to the MFGM without heating. Binding of caseins and whey proteins and loss of membrane proteins were not significantly different between milk samples that were homogenized before and after heating. Viscosity of whole milk was increased when milk was treated with both homogenization and heating.


2014 ◽  
Vol 81 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Jing Lu ◽  
Toon van Hooijdonk ◽  
Sjef Boeren ◽  
Jacques Vervoort ◽  
Kasper Hettinga

Lactation physiology is a process that is only partly understood. Proteomics techniques have shown to be useful to help advance the knowledge on lactation physiology in human and rodent species but have not been used as major tools for dairy cows, except for mastitis. In this paper, advanced non-targeted proteomics techniques (Filter aided sample preparation and NanoLC-Orbitrap-MS/MS) were applied to study the milk fat globule membrane and milk serum fraction, resulting in the identification of 246 proteins. Of these, 23 transporters and enzymes were related to lipid synthesis and secretion in mammary gland and their functions are discussed in detail. The identification of these intracellular transporters and enzymes in milk provides a possibility of using milk itself to study lipid synthesis and secretion pathways. This full-scale scan of milk proteins by using non-targeted proteomic analysis helps to reveal the important proteins involved in lipid synthesis and secretion for further examination in targeted studies.


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