Varying Levels of Medium-Chain Fatty Acids Affect Triacylglycerol Composition and Crystallization Behavior of African Elephant Milk Fat

African elephant milk fats from different stages of lactation are studied to investigate the link between high contents of medium-chain fatty acids (MCFA), triacylglycerol (TAG) species, and crystallization in a milk fat system. The elephant milk fats contain high amounts of MCFA, specifically C8:0, C10:0, and C12:0, which mainly form medium molecular weight TAG species (C26-C34). The milk fats with the highest MCFA levels (97% and 82%) correspond to mid- and late-lactation stages. These milk fats display simpler TAG compositions and crystallization behaviors. The great majority of mid- and late-lactation milk fats are comprised of medium molecular weight (C28-C30) TAG. Both melting and crystallization are sharp events, and only beta' polymorph is observed. At early lactation, with 66% MCFA, a more diverse fatty acid composition is observed, and TAG species with medium molecular weight (C30-C34) and high molecular weight (C36-C44) are the dominant. Under dynamic conditions, crystallization and melting take place gradually over a wide temperature range, both alpha and beta' polymorph crystals are observed. Practical Applications: Mammals of different species provide milk lipids with a wide variety of fatty acid composition yet with common stereospecific features. The study of milk lipids, other than the common bovine milk lipids, allows the investigation of crystallographic properties in relation to fatty acid composition while preserving the stereospecific arrangement. Specifically, the study of elephant milk fats from different stages of lactation provides insight in to the effect of varying contents of medium-chain fatty acids and fatty acid diversity on triacylglycerol composition and crystallization behavior.