What are triglycerides?

The National Academy of Sciences defines fats and oils as “complex organic molecules that are formed by combining three fatty acids with one molecule of glycerol”. Triglycerides, or triacylglycerols, are the terms used to define this molecular structure combining three fatty acids (i.e. EPA and DHA) esterified

What are ethyl esters and how are they produced?

Fatty acid ethyl esters are a class of lipids that are derived by reacting free fatty acids with ethanol (alcohol). Called trans-esterification, the process involves a reaction whereby the glycerol backbone of a TG is removed and substituted with ethanol. The resulting EE allow for the fractional distillation (concentration) of the long chain fatty acids at lower temperatures. Commonly referred to as molecular distillation in the fish oil industry this step allows for the selective concentration of the EPA and DHA fatty acids to levels greater than found naturally in fish. The resulting EPA and DHA concentrate is typically the end product that is subsequently marketed and sold as “Fish Oil Concentrate”. This situation presents several issues because the term fat or oil refers only to TG, the EPA and DHA ethyl concentrate is, by definition, no longer a fat or oil and is incorrectly marketed as fish oil. Because EEs rarely occur in nature this affects the way they are digested and absorbed in the body.