Margarine containing partially hydrogenated soybean oil is solid because
A). it contains only saturated fats.
B). it contains only trans fatty acids.
C). some of its double bonds have been converted to single bonds.
D). it contains only cis double bonds.
E). it contains only polyunsaturated fatty acids.
The Correct Answer and Explanation is:
The correct answer is C). some of its double bonds have been converted to single bonds.
Explanation:
Margarine containing partially hydrogenated soybean oil is solid because of the process called partial hydrogenation, which alters the chemical structure of the fatty acids in the oil. Soybean oil is typically liquid at room temperature because it contains unsaturated fatty acids, which have one or more double bonds in their carbon chains. These double bonds create kinks in the molecular structure, preventing the molecules from packing closely together and keeping the oil in a liquid state.
During partial hydrogenation, some of these double bonds (which are typically cis double bonds) are chemically converted into single bonds, resulting in a more saturated structure. This process turns some of the unsaturated fatty acids into trans fatty acids (a type of unsaturated fat), which are structurally different from their natural, cis counterparts. The trans configuration allows the fatty acids to pack more closely together, increasing the melting point of the fat and causing it to be solid at room temperature.
However, not all of the double bonds are fully hydrogenated, and some remain as trans fatty acids. This partial hydrogenation gives margarine a consistency that is neither as soft as the original oil nor as hard as pure saturated fats like butter. The conversion of double bonds to single bonds during partial hydrogenation is what makes margarine more solid compared to its original liquid form.
It’s important to note that trans fatty acids (which are a byproduct of the hydrogenation process) have been linked to various health risks, including an increased risk of heart disease. This is one of the reasons why there has been a shift away from partially hydrogenated oils in many food products.
Therefore, option C accurately explains why margarine is solid, as the hydrogenation process converts some of the unsaturated bonds to single bonds.