Why do carrots turn mushy when cooked?

Answer: Pectin breaks down releasing water

Pectin breaks down releasing water ✓ — Correct! Raw carrots have firm cell walls held together by pectin (a polysaccharide). Cooking breaks down pectin bonds (especially above 80°C), softening cell walls. Water enters cells, making carrots soft and mushy. Longer cooking = more pectin breakdown = mushier texture. That's why raw carrots are crunchy but cooked ones are soft!

Vitamins dissolve out and leave gaps in tissue — Wrong. Some vitamins do leach, but texture change is specifically from pectin breakdown weakening cell walls, not vitamin loss.

Cellulose fibers absorb water and swell up — Wrong. Cellulose fibers are rigid and do not swell enough to cause mushiness; pectin degradation in cell walls is the cause.