Relationship between activity of some fat globule membrane enzymes and the lipidic fraction in ewes' milk: Preliminary studies

The aim of this preliminary study was to improve the knowledge about milk fat globules by studying the relationships between the morphometric characteristics of fat globules, the fatty acid composition and the activity of membrane enzymes evaluated in 14 milk samples from Massese ewes: xanthine oxidase (XO), xanthine dehydrogenase (XDH), gamma-glutamyl transpeptidase (gamma-GT), alkaline phosphatase (AP) and 5'-nucleotidase (5'-N). A negative correlation was found between the activity of XO and XDH and fat globule size, and a positive correlation between AP activity, the number of globule per mL and medium fat globules (2-5 mu m). A significant relationship was found between the enzymatic activity of gamma-GT, XO, XDH, 5'-N and various fatty acids in milk. (C) 2009 Elsevier Ltd. All rights reserved.