Question 11.6: Linoleic acid (cis, cis-9,12-octadecadienoic acid) is an ess...
Linoleic acid (cis, cis-9,12-octadecadienoic acid) is an essential fatty acid. This means that we must obtain it in the diet, because we cannot make it. Fortunately, it is found in abundance in sunflower, safflower, and corn oil, which are often hydrogenated to produce margarine. Write a balanced equation showing the hydrogenation of linoleic acid.
First, notice that there are two double bonds. This means that we will need two molecules of H_2 for every molecule of linoleic acid that is hydrogenated.
The liquid linoleic acid is converted to stearic acid, which is a rather hard solid. In margarine production today, partial hydrogenation is generally used because it produces a fat that can be more easily spread and has a better “mouth feel.” They may then add butter flavoring, milk solids, salt, an emulsifying agent, preservatives, vitamin A for nutritional value, and a bit of β-carotene for color.
