Molecular weight distributions of milk fat triglycerides from seven species

W.C Breckenridge,A Kuksis

doi:10.1016/s0022-2275(20)38904-5

Abstract

The triglyceride compositions of the milk fats of man, dog, guinea pig, cow, sheep, goat, and horse were compared by gas-liquid chromatography of the intact triglycerides and of the butyl esters of the component fatty acids. The milk fats of man, dog, and guinea pig, which were largely made up of long-chain fatty acids, showed a common pattern with major contributions made by the glycerides with 48-54 acyl carbon atoms. The milk fats of cow, sheep, and goat, which were rich in short-chain acids, showed significant proportions of triglycerides with 28-54 acyl carbon atoms. Horse milk, which contains large amounts of medium-chain fatty acids, gave a characteristic triglyceride pattern in the 26-54 carbon atoms range. The experimentally determined distributions of the molecular weights of the triglycerides of all milk fats deviated significantly from the distributions predicted by random association of the fatty acids from a single pool. The data suggest that in all species the milk fat may be formed by a partial resynthesis of preformed glycerides.

Highlights

The triglyceride compositions of the milk fats of man, dog, guinea pig, cow, sheep, goat, and horse were compared by gas-liquid chromatography of the intact triglycerides and of the butyl esters of the component fatty acids
Reports on gas-liquid chromatography chromatographic (GLC) analyses of intact triglycerides of milk fats have been limited to the cow [5] and goat ( 6 )
This report provides in detail the molecular weight distributions of the milk fat triglycerides of seven species and compares the data to the appropriate random predictions

Summary

Milk Samples

The milk was obtained from individual mature and healthy females 2-4 wk after parturition. Single samples were collected from horse, sheep, goat, and dog, duplicate samples from guinea pig, and multiple samples from man and cow. The samples varied in size from 1-2 ml (guinea pig) to 10-50 ml (dog, horse, goat, and sheep) and 100-250 ml (man and cow). All the animal milks were collected in the fall (October-November). The sheep, horse, and goat were grazing or received hay. The cows were grazing and received a supplement of dairy meal. The guinea pigs were on rat chow, while the JOURNAOLF LIPIDRESEARCHVOLUME8.

Isolation of Triglycerides

RESULTS AND DISCUSSION

Goat Sheep Horse

Experimental Randomt