Final answer:
The hydrocarbon tails in vegetable oils undergo hydrogenation, where hydrogen atoms are added to the double bonds, converting them to single bonds to produce margarine. Catalytic hydrogenation increases the melting point, allowing oils to become more solid and spreadable. Partial hydrogenation is often used to achieve a desired semi-solid consistency. The correct option is B. The removal of double bonds (i.e., changing them to single bonds and adding hydrogen atoms).
Step-by-step explanation:
Margarine is made from vegetable oils in which the hydrocarbon tails have had hydrogen atoms added to the double bonds, converting them to single bonds in a process called hydrogenation. Vegetable oils are composed of triglycerides with unsaturated fatty acids that contain one or more carbon-carbon double bonds (C=C). These double bonds are chemically altered through catalytic hydrogenation.
During this process, conducted in the presence of a catalyst like nickel, hydrogen gas is bubbled through the oils. This converts C=C double bonds to C-C single bonds, making the oil more solid and increasing its melting point, which allows the production of spreadable margarine.
The goal of hydrogenation is to create a product with a texture and shelf life similar to butter, by transforming unsaturated fatty acids into saturated ones. However, it's important to note that partial hydrogenation can lead to the formation of trans fats, which have been associated with negative health effects.
As a result, partial hydrogenation is often used to achieve the desired consistency without completely eliminating the presence of double bonds.