Interchangeability of fats and Oils

The requirement for interchangeability of fats and oils is a result of such factors as availability and cost of raw materials, and the effects of legislation or market preference on product composition. Such changes should not affect the product's quality or performance. Interchangeability is practiced today in the production of products for human food, animal feed and technical uses, and is frequently controlled by computer. It is necessary fully to identify a product and its essential features whether simply by melting point or a full triglyceride structure. Modern analytical techniques such as NMR, GC, HPLC and DSC have enabled this identification to become a more exact science. The interchange may consist of a simple substitution of one oil or fat for another, or it may be more complex, involving a number of oils and fats and processes. Finally, the nature of the product may be such that it has to be “tailor‐made” using sophisticated processes to produce the required triglyceride composition. The unit processes which are employed are blending, hydrogenation, fractionation and interesterification. In the last process the recently published use of enzymes is of particular interest. Problems encountered are mainly concerned with the polymorphism of fats and oils which frequently sets limits on the proportion of a particular fat which can be used. Limits are also imposed by plant processing capacity. Palm and lauric acid oils are particularly important in the context of interchangeability for both edible and technical purposes because of their fatty acid and triglyceride compositions. They provide good examples of usefulness, problems resulting from polymorphism and the difficulties of substitution.