Question

Extrusion cooking is accomplished in four different stages, which are indicated as I, II, III and IV in the figure given below. Choose the correct option representing the name of each stage. 

• A. I – Feeding, II – Cooking, III – Kneading, IV – Expansion
• B. I – Kneading, II – Feeding, III – Cooking, IV – Expansion
• C. I – Feeding, II – Kneading, III – Cooking, IV – Expansion
• D. I – Cooking, II – Kneading, III – Feeding, IV – Expansion

Hint:

In extrusion: Feed → Knead → Cook → Expand. Remember FKCE.

Answer 1

The Correct Option is C

Step 1: Identify the stages in extrusion cooking.
- Stage I: Feeding — raw material is fed into the extruder.
- Stage II: Kneading — the material is subjected to mixing and shear forces.
- Stage III: Cooking — high pressure and temperature cook the mixture.
- Stage IV: Expansion — as the material exits the die, pressure drops and the product expands.
Step 2: Match with the figure.
The graph shows a gradual rise in pressure/temperature (kneading), a peak (cooking), and a sudden drop (expansion). Therefore, the correct order is I–Feeding, II–Kneading, III–Cooking, IV–Expansion.