Explain the changes that take place in food during freezing and frozen storage.

1. 1 · Open in two lines. Freezing keeps food safe for months, but physical, chemical and microbial changes can lower its quality.
2. 2 · Physical changes.
   • Ice crystal damage and drip loss on thawing.
   • Freezer burn from sublimation.
   • Recrystallisation when temperature swings.
   • Expansion by about 9%.
3. 3 · Chemical changes.
   • Protein denaturation: tough, dry fish.
   • Fat oxidation: rancid fatty fish.
   • Enzymic browning and off-flavours if not blanched.
4. 4 · Draw a table. [Table: change | cause | prevention]
5. 5 · Microbes. Some die, many survive; thawed food spoils faster than fresh.
6. 6 · Nutrition link. Drip carries vitamins and minerals; cook frozen vegetables straight from the pack.
7. 7 · Close in one line. Quick freezing, tight packing and a steady −18 °C keep these changes small.

Scoring tip: A three-column table (change, cause, prevention) is the fastest way to score here.