Triglyceride Structure of Cows’ Milk Fat. I. Preliminary Observations on the Fatty Acid Composition of Positions 1, 2, and 3

Abstract

Milk fat was subjected to a modified Brockerhoff stereospecific analysis to determine the fatty acid composition of positions 1-, 2-, and 3-(Hirsch-mann). The 2-position as determined by phospholipase A digestion was in reasonable agreement with the composition of 2-monoglycerides from pancreatic lipolysis. None of the fatty acids were randomly distributed nor did any fit a 1,3-random 2-random distribution pattern. The 1-, 2-, and 3-positions contained 5.01, 2.89, and 43.33 moles % 4:0 respectively. Since 84% of the 4:0 was in the 3-position many of the butyrate glycerides exist as single enantiomers. The implications of acyl migration of 1,2- to 1,3-diglycerides are discussed.