Question

The yellow colour of the cow milk is due to the presence of__________

• A. sterols
• B. albumin
• C. phospholipids
• D. carotenoids

Hint:

Associate carotenoids with yellow/orange colors in nature (e.g., carrots). Remember that since beta-carotene is fat-soluble, the yellow color in milk is more prominent in the cream or butter. This is why butter from grass-fed cows is more yellow.

Answer 1

The Correct Option is D

Step 1: Concept Overview:
The color of milk and milk fat is determined by the cow's diet. Fat-soluble pigments from the cow's feed transfer into the milk.
Step 3: In-Depth Analysis:
- Carotenoids, notably beta-carotene, are yellow-orange pigments prevalent in green forage such as grass, a significant component of a cow's diet.
- Beta-carotene is fat-soluble. After ingestion, it is absorbed by the cow and dissolves into the milk fat globules.
- This imparts a yellowish tint to the milk fat. The color's intensity varies based on the cow's breed and the quantity of green feed consumed. This coloration is more pronounced in high-fat dairy products like cream and butter.
- While sterols, albumin (a protein), and phospholipids are also present in milk, they are colorless and do not contribute to the yellow hue.
Step 4: Conclusion:
The yellow color in cow's milk arises from carotenoid pigments, mainly beta-carotene, dissolved within the milk fat. Consequently, option (D) is the correct answer.