Casein Protein Source Identification

Casein is a type of phosphoprotein that makes up a significant portion of the protein found in mammalian milk. It is known for its slow digestion rate compared to other proteins like whey.

Primary Source of Casein

Casein is predominantly found in milk and dairy products. It constitutes about 80% of the total protein content in cow's milk.

Analysis of Options

• Soya bean: Contains proteins like glycinin and conglycinin, not casein.
• Milk: The primary and well-known source of casein protein.
• Meat: Primarily composed of muscle proteins like actin and myosin.
• Carrot: A vegetable, contains carbohydrates, fiber, vitamins, and minerals, but negligible protein, and no casein.

Therefore, casein is a protein found in milk.