A
Q: What is the main purpose of freezing food?
To slow microbial growth and chemical reactions, thereby extending shelf life.
What is thawing?
The process of changing frozen food from a solid/frozen state back to an unfrozen state.
At approximately what temperature does water freeze?
A: 0°C.
Name one major industrial method of freezing.
A: Air-blast freezing.
What is freezer burn?
Surface dehydration of frozen food caused by moisture loss, resulting in dry, discolored patches.
Explain why lipid oxidation can still occur in frozen foods.
Freezing slows oxidation but does not completely stop it; oxygen and enzymes can still promote oxidation, causing rancidity and off-flavors.
Differentiate between slow freezing and fast freezing in terms of ice crystal formation.
Slow freezing forms large ice crystals that can damage cells, while fast freezing forms many small crystals that cause less cellular damage.
Why is fast freezing preferred over slow freezing for most foods?
Fast freezing forms small ice crystals, which cause less damage to food cells and help maintain better texture, appearance, and quality after thawing.
Why does protein denaturation occur during frozen storage, and what effect can it have?
Freezing concentrates salts and other solutes around proteins, altering their structure. This can reduce protein functionality and cause texture changes, especially in meat and fish.