CORANDOMIZATION OF FATS IMPROVES ABSORPTION IN RATS

Human milk fat is well absorbed despite its large concentration of lon g-chain saturated fatty acids (LCSFA), particularly palmitic acid. The superior absorption has been ascribed in part to the uncommonly high proportion of the palmitic acid in the sn-2 position of the triglyceri des, 70% in human milk triglycerides compared with 10-15% in the fats and oils commonly used in infant formula blends. Colipase-dependent pa ncreatic lipase selectively hydrolyzes the fatty acids at the sn-1 and 3 positions, yielding free fatty acids and the 2-monoglyceride, which are absorbable. Free palmitic acid, but not monopalmitin, can be lost as calcium soaps in the feces. The present study demonstrated that mi xtures of coconut oil and palm olein are better absorbed by rats if th e proportion of LCSFA in the sn-2 position is increased by the process of chemical randomization, in which the fatty acids of the native oil s are redistributed equally to all three positions in the rearranged t riglycerides. The fecal excretion of total fatty acids, essentially LC SFA, from the mixtures in which the oils were randomized together (cor andomized) was 30 to 60% less than from the mixtures of native oils.