Food Purchasing, Storage, Preservation and Food Safety/Hygiene
What this domain tests
This domain tests wise food buying, correct storage, preservation principles and safe hygiene. Exam questions may ask you to choose a preservation method for a local food, explain why a practice is unsafe, or sequence safe handling steps.
Core rules and concepts
- Purchasing: buy seasonal, local and fresh foods; check labels, expiry dates and packaging; avoid damaged cans, mouldy grains and swollen packets; compare unit prices.
- Storage: keep dry foods cool, dry and dark in airtight containers; use first-in, first-out; separate raw and cooked foods; refrigerate at 0–5 °C and freeze at −18 °C or below.
- Preservation works by removing moisture, lowering temperature, raising acidity or salt/sugar concentration, excluding oxygen, or killing microorganisms. Examples include drying, smoking, salting, pickling, fermentation, canning and freezing.
- Food safety: wash hands with soap and safe water; keep surfaces clean; cook thoroughly; keep food out of the 5–60 °C danger zone; protect food from flies, dust and rodents; use safe water.
Worked example
You buy 5 kg of dried beans at a busy market. Choose a storage plan and justify it. Reasoning: beans spoil through moisture, insects and mould. Spread them in a thin layer to cool and dry; remove stones and damaged beans; pack in clean, dry, airtight containers; store in a cool, dark, raised place; label with the purchase date; use older stock first. Do not store beans in a damp sack on the floor or beside kerosene, because moisture, pests and odours cause loss. If insects appear, sun-dry or freeze and inspect before use rather than simply adding more pesticide.
Traps that cost marks
- Refrigeration slows bacteria; it does not kill them.
- Reheating food does not make unsafe food safe, and repeated reheating increases risk.
- Mouldy grains may contain mycotoxins; removing visible mould does not make the whole batch safe.
- Botulism risk is linked to low-acid foods in sealed, oxygen-free conditions, such as poorly processed canned foods.
- Cross-contamination from cutting boards, hands or cloths is a common exam answer.