What is the liquid remaining after renin treatment of milk?

• A. Whey
• B. Coagulum
• C. Cream
• D. Skim Milk

Answer: (A)

Renin (rennet) cleaves a part of the casein micelle, κ-casein, which normally stabilizes milk. This destabilization causes the milk proteins to coagulate into a solid curd, forming a coagulum that traps fat and some minerals. The liquid that drains away from this curd is whey. It’s the watery part containing water, lactose, whey proteins, and minerals, while the coagulum is the solid curd. Cream is simply the fat layer that can separate, and skim milk is milk with fat removed, not the liquid left after coagulation. So the liquid remaining after renin treatment is whey.