Question

The major milk protein is:

• A. Prolamin
• B. Lactoglobulin
• C. Lactalbumin
• D. Casein

Hint:

Casein exists in milk in the form of "micelles." These micelles scatter light and are responsible for the characteristic white, opaque appearance of milk.

Answer 1

The Correct Option is D

Concept: Milk proteins are broadly classified into two main groups based on their behavior at pH 4.6.

• Caseins: Phosphoproteins that precipitate at pH 4.6.

• Whey Proteins: Remain soluble in the serum (lactalbumin and lactoglobulin).

Step 1: Distribution of proteins in milk.
In bovine (cow) milk, the total protein content is approximately 3.3% to 3.5%. This protein is divided between caseins and whey proteins.

Step 2: Identifying the dominant fraction.
Casein accounts for approximately 80% of the total milk protein. Whey proteins (albumin and globulin) account for the remaining 20%.

Step 3: Conclusion.
Because casein constitutes the vast majority of the protein content: It is designated as the major milk protein. Final Answer: (D)