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: Understanding the Concept:
The color of milk and milk fat is influenced by the diet of the cow. Certain pigments from the cow's feed are fat-soluble and can be transferred into the milk.
Step 3: Detailed Explanation:
- Carotenoids, particularly beta-carotene, are yellow-orange pigments found abundantly in green forage like grass, which is a major part of a cow's diet.
- Beta-carotene is a fat-soluble pigment. When consumed by the cow, it is absorbed and gets dissolved in the milk fat globules.
- This gives the milk fat a yellowish hue. The intensity of the color depends on the breed of the cow and the amount of green feed in its diet. This color is especially concentrated in products with high fat content, like cream and butter.
- Sterols, albumin (a protein), and phospholipids are other components of milk, but they are colorless and do not contribute to the yellow color.
Step 4: Final Answer:
The yellow color in cow's milk is caused by the presence of carotenoid pigments, primarily beta-carotene, dissolved in the milk fat. Therefore, option (D) is correct.