Structural Analysis of Triglyceride Classes Obtained from Cow's Milk Fat by Fractional Crystallization

Abstract
Cows'' milk fat was separated into fractions by crystalization from acetone at -25 and -70 C. The triglyceride structure of eachiraction was analyzed by pancreatic lipolysis. The relative amounts of short-chain and unsaturated acids increased as the temperature of crystallization decreased. Distribution of acid was non-random in all fractions. Inter-molecular specificity (differential rates of triglyceride hydrolysis) was evident. Dibutyryl triglycerides which could have concentrated in the -70 C soluble fraction, were present in very small quantities, if at all.