Question

Which is the correct descending order of level of saturated fatty acids in following fats of animal origin?

• A. milk fat $>$ beef $>$ pig $>$ chicken $>$ marine fish
• B. beef $>$ milk fat $>$ chicken $>$ pig $>$ marine fish
• C. chicken $>$ beef $>$ pig $>$ marine fish $>$ milk fat
• D. milk fat $>$ beef $>$ pig $>$ marine fish $>$ chicken

Hint:

Ruminant fats (milk fat, beef) are always more saturated than non-ruminant animal fats (pig, poultry) and fish oils due to microbial biohydrogenation in the rumen.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Animal fats vary in their fatty acid profiles depending on the species' digestive physiology (ruminant vs. non-ruminant), diet, and lipid synthesis pathways.
Saturated fatty acids (SFAs) contain no double bonds, making them stable and solid at room temperature.

Step 2: Detailed Explanation:
Let us compare the average saturated fatty acid (SFA) content in the given fats:
Milk fat: Milk fat has the highest SFA content (about 65% to 70% of total fatty acids).
This is due to biohydrogenation of dietary unsaturated fats by rumen microorganisms and active de novo synthesis of short-chain and medium-chain saturated fatty acids in the mammary gland.
Beef fat (Tallow): As a ruminant depot fat, it is also highly saturated (about 45% to 50% SFAs) due to rumen biohydrogenation.
Pig fat (Lard): As a non-ruminant fat, it has a lower SFA content (about 35% to 40% SFAs) and contains more monounsaturated oleic acid.
Chicken fat: Poultry fat is relatively unsaturated, containing only about 30% SFAs, with high levels of monounsaturated and polyunsaturated fatty acids.
Marine fish oil: Fish lipids are highly unsaturated, containing only about 20% SFAs and rich in long-chain omega-3 polyunsaturated fatty acids (EPA and DHA).
Therefore, the correct descending order of SFA content is: milk fat $>$ beef $>$ pig $>$ chicken $>$ marine fish.

Step 3: Final Answer
The correct option is (A).