Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): Ghee, though has a lower content of unsaturated fatty acids than most of the plant oils, has a lower shelf life than plant oils
Reason (R): Plant oils contain high levels of antioxidants and hence, have a long shelf life
In light of the above statements, choose the correct answer from the options given below.

• A. Both (A) and (R) are true and (R) is the correct explanation of (A)
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
• C. (A) is true but (R) is false
• D. (A) is false but (R) is true

Hint:

Saturated fats are highly stable because they lack double bonds, which are the primary sites for free-radical attack during autoxidation. Because ghee consists mostly of saturated lipids, it is naturally more stable than highly unsaturated vegetable oils.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The shelf life of fats and oils is determined by their susceptibility to autoxidation (oxidative rancidity).
Unsaturated fatty acids, which contain double bonds, are highly prone to oxidation, whereas saturated fatty acids are stable and resistant to oxidative deterioration.

Step 2: Detailed Explanation:
Let us analyze both statements:
- Assertion (A): Ghee is a anhydrous milk fat product consisting predominantly of saturated fatty acids (~60-70%) and very low levels of polyunsaturated fatty acids. Because of this high saturation and extremely low moisture content (\(< 0.5\%\)), ghee is highly resistant to autoxidation and microbial spoilage. It has an exceptionally long shelf life, often exceeding 6 to 12 months at room temperature.
- In contrast, most vegetable/plant oils contain high levels of monounsaturated and polyunsaturated fatty acids (such as oleic, linoleic, and linolenic acids), which are highly vulnerable to oxidative rancidity and can develop off-flavors quickly unless stabilized.
- Therefore, the assertion that ghee has a "lower shelf life than plant oils" is chemically and practically false. Ghee generally has a longer shelf life.
- Reason (R): Many unrefined plant oils contain natural antioxidant compounds, such as tocopherols (Vitamin E), which scavenge free radicals and help extend their shelf life. Thus, the Reason (R) is true.
- Since (A) is false but (R) is true, the correct option is (D).

Step 3: Final Answer:
(A) is false but (R) is true.