HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Sundheim, G. Articles by Bengtsson-Olivecrona, G. Search for Related Content PubMed PubMed Citation Articles by Sundheim, G. Articles by Bengtsson-Olivecrona, G.

Methods to Assess the Propensity of Milk Fat Globules Toward Lipolysis and the Ability of Skim Milk to Inhibit Lipolysis

Department of Animal Nutrition, Agricultural University of Norway, P.O. Box 25 N-1432 Ås-NLH, Norway

Gunilla Bengtsson-Olivecrona

Department of Physiological Chemistry, University of Umeá, S-901 87 Umeá, Sweden

ABSTRACT

Methods to quantitate factors in milk relevant to cold-induced lipolysis are described. Skim milk was incubated with milk fat globules isolated from a pool of normal milk and a fixed amount of purified lipoprotein lipase. The release of fatty acids in 24 h at 4°C was determined. Most skim milk samples inhibited lipolysis, but the effect varied greatly. Skim milk from milk prone to spontaneous lipolysis was less inhibitory than skim milk from normal milk. In general, both the casein and the serum fractions of skim milk inhibited lipolysis. However, variation was greater in the effects of individual samples of milk serum. In a few extreme cases, with samples from milk with spontaneous lipolysis, the serum fraction actually stimulated lipolysis. Globules were isolated and then incubated with skim milk from normal milk and a fixed amount of purified lipoprotein lipase. This gave a measure of accessibility to lipolysis of milk fat globules in normal skim milk. There was a considerable variation in propensity toward lipolysis between milk fat globules from individual milk samples. Milk showing different levels of lipolysis obtained from five cows revealed that skim milk inhibition of lipolysis and the propensity of milk fat globules toward lipolysis were characteristic for each cow.