Preparation of medium chain triglycerides with the use of physical refining

The medium chain fatty acids are prepared by fractional distillation of coconut and palmkernel oil fatty acids and the industrial synthesis of MCTs is much more complicated than the preparation of common edible oils. The esterification of medium chain fatty acids with glycerol must lead to an almost complete elimination of monoglycerides because of their bitter taste. The free fatty acid content of the end product has to be very low and the deodorization step creates problems owing to the hydrolysing action of the steam. The necessity of using a large excess of fatty acids in the esterification step to eliminate the monoglycerides, results in considerable refining losses, which increase the cost of MCTs manufacture. The present investigation was carried out with the object of replacing the alkali treatment of the esterified product by physical refining, i.e. by the removal of free fatty acids by distillation. This was achieved by dispensing with the use of a catalyst during the esterif ication and by using nitrogen or preferably carbon dioxide instead of steam during the deacidification-deodorization step. This permitted a substadtial increase in the temperature of the process and the formation of a satisfactory product in a reasonable working time.