Journal of Dairy Research

Table of Contents - 2004 - Volume 71, Issue 04  


Interactions of fat globule surface proteins during concentration of whole milk in a pilot-scale multiple-effect evaporator

Aiqian Ye a1, Harjinder Singh a1c1, Michael W Taylor a1 and Skelte G Anema a1a2
a1 Riddet Centre and Institute of Food, Nutrition and Human Health, Massey University, Private Bag 11222, Palmerston North, New Zealand
a2 Fonterra Research Centre, Private Bag 11029, Palmerston North, New Zealand

Article author query
ye a   [PubMed][Google Scholar] 
singh h   [PubMed][Google Scholar] 
taylor mw   [PubMed][Google Scholar] 
anema sg   [PubMed][Google Scholar] 

Abstract

The changes in milk fat globules and fat globule surface proteins during concentration of whole milk using a pilot-scale multiple-effect evaporator were examined. The effects of heat treatment of milk at 95 °C for 20 s, prior to evaporation, on fat globule size and the milk fat globule membrane (MFGM) proteins were also determined. In both non-preheated and preheated whole milk, the size of milk fat globules decreased while the amount of total surface proteins at the fat globules increased as the milk passed through each effect of the evaporator. In non-preheated samples, the amount of caseins at the surface of fat globules increased markedly during evaporation with a relatively small increase in whey proteins. In preheated samples, both caseins and whey proteins were observed at the surface of fat globules and the amounts of these proteins increased during subsequent steps of evaporation. The major original MFGM proteins, xanthine oxidase, butyrophilin, PAS 6 and PAS 7, did not change during evaporation, however, PAS 6 and PAS 7 decreased during preheating. These results indicate that the proteins from the skim milk were adsorbed onto the fat globule surface when the milk fat globules were disrupted during evaporation.

(Received August 9 2003)
(Accepted January 12 2004)


Key Words: Evaporation; fat globules; fat globule surface proteins; milk fat globule membrane (MFGM); caseins; whey proteins.

Correspondence:
c1 e-mail: H.Singh@massey.ac.nz