Question

Margarine is a butter substitute that is solid at room temperature. It is made from vegetable oils (often soybean or canola oil). The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. Which statement below makes sense?

a) The hydrogenated vegetable oil is less likely to clog arteries compared to butter.
b) The hydrogenated vegetable oil stays solid at room temperature because the fatty acid chains have been saturated with hydrogens, breaking the double bonds between carbons.
c) The hydrogenated vegetable oil has more "kinks" in the fatty acid chains, compared to non-hydrogenated oil,causing it to be solid at room temperature.
d) The hydrogenated vegetable oil has a lower melting point.

Answer 1

The correct answer is: b).

Step-by-step explanation:

• Oil or solid fat is composed of long chains made up of hydrocarbons (fatty acids).
• The fatty acid can be:

1. Saturated - in which all the carbon atoms in the long hydrocarbon chain are linked to each other by single bonds. As a result of this there is a tight packing between the fatty acid molecules which gives them a solid texture at room temperature.
2. Unsaturated - in which there are one or more double or triple bonds in between carbon atoms in the long hydrocarbon chain. As a result of this kinks or bends develop in the fatty acid chain which results in generation of space or gap in between fatty acid chains. This gives the fatty acid the capability to move as a result of which they have a liquid texture at room temperature.

• Hydrogenation is a process by which the unsaturated fatty acids (oil) are converted to saturated fatty acid (margarine) by reducing the multiple bonds in between the carbon atoms with hydrogen.
• Hydrogenated oil has a higher melting point and so it is solid at room temperature.
• Hydrogenated oil can also cause clogging in the arteries as they cannot be easily broken down due to their increased stability.