NFS

• Importance of maintaining cleanliness in the kitchen to prevent pests or the growth of microorganisms that can contaminate food
• Hygiene practices to maintain kitchen cleanliness:

  • Wash cooking utensils, crockery, storage containers, and chopping boards immediately after use; do not leave dirty items overnight in the sink
  • Store clean and dry utensils and crockery on shelves or in cupboards
  • Wash and disinfect tea towels and dishcloths regularly
  • Keep the sink, stove, and preparation areas clean, and disinfect frequently
  • Line the rubbish bin with a trash bag and keep it covered; tie trash bag tightly before disposing of it; empty rubbish bin at the end of the day
  • Replace the cleaning sponge regularly
• Storage guidelines for dairy products and eggs:

  • Milk should be stored in the refrigerator; unopened UHT milk can be stored at room temperature but refrigerated once opened
  • Cheese, cream, butter, and yogurt should be covered and stored in the chiller
  • Eggs can be kept at room temperature if used within a few days; otherwise, store in the chiller to prolong shelf life; do not wash eggs as the protective layer will be destroyed
• Guidelines for storing fruit and vegetables:

  • Remove wilted leaves from leafy vegetables; wrap them in paper towels to absorb moisture and prevent wilting
  • Store fruit and vegetables in the crisper compartment of the refrigerator
• General guidelines for storing food items:

  • Store items with earlier expiry dates at the front of shelves
  • Maintain chiller temperature at 0°C to 4°C and freezer at -18°C and below
  • Canned and dried foods can be kept at room temperature away from direct sunlight
  • Check grains and cereals occasionally for weevils
• Guidelines for storing raw meat, poultry, and seafood:

  • Seal raw meat in plastic bags or airtight containers and place on shelves below cooked food
  • Store on the lower shelf of the chiller if used on the day; otherwise, store in the freezer
  • Large cuts of meat should be cut into smaller cuts and packed separately before freezing to thaw faster before cooking
• During cooking and serving food, ensure:

  • Cooked food is stored in the refrigerator once cooled down to prevent bacterial growth
  • Cooked food is stored in airtight containers or covered properly and stored on shelves above raw meat to avoid cross-contamination
  • Food is cooked to a minimum internal temperature of 75°C to prevent microbial growth
• Precautions during food preparation:

  • Practise good personal hygiene: wash hands before handling food, wear clean clothes and appropriate protective equipment, cover cuts and wounds
  • Prevent cross-contamination: do not mix cooked and raw food, use separate utensils for different food types
  • Maintain food safety of thawed food: do not refreeze thawed food, thaw frozen food on the lowest shelf of the chiller or in a microwave set to "defrost" mode
  • Use the "First In, First Out" (FIFO) principle to use food with earlier expiry dates first
• Fats turn rancid in the presence of oxygen, heat, and light, breaking into glycerol and fatty acids, producing a distinct off-odour and an unpleasant taste
• High-fat foods should be stored in a cool place, away from direct sunlight to reduce the occurrence of rancidity
• Foods prone to rancidity include whole grains, nuts, potato chips, and prawn crackers
• Physical spoilage occurs when food is physically damaged during harvesting, handling, distribution, or storage, including flesh bruising, broken skin, or damage caused by insects and rodents
• Weevils and other pests can infest opened packages of rice, grain, or flour, damaging the food and potentially contaminating it with microorganisms
• Environmental factors like light, oxygen, warm temperatures, moisture, and acidity play a role in food spoilage
• Light can destroy light-sensitive vitamins and speed up undesirable chemical reactions like the rancidity of fats
• Oxygen encourages the growth of microorganisms in food and accelerates the rancidity of fats and enzymatic browning
• Warm temperatures increase occurrences of enzymatic browning and rancidity, with microorganisms growing faster at warm temperatures
• An acidic environment encourages yeast growth in fruit juices but prevents bacterial growth
• Bacterial food poisoning can be caused by species like salmonella, vibrio, and Escherichia coli, commonly found in contaminated eggs, raw poultry, shellfish, beef, and lamb
• Yeasts survive in moist conditions and thrive in food with high sugar concentrations and low pH, appearing as slimy patches on the food's surface
• Moulds grow on the surface of food as fuzzy spots of various colors, requiring little moisture to survive and reproducing by producing spores
• Moulds also produce toxic substances called mycotoxins, which can cause severe health effects if present in food at high levels
• Food spoilage occurs due to undesirable changes in nutritive value, color, flavor, or texture, but the food may still be safe to eat if not contaminated
• Microbial spoilage is caused by bacteria, yeast, and mould, thriving in food not stored or handled properly
• Bacteria, smaller than yeasts or moulds, thrive under moist conditions at room temperature around a neutral pH, easily contaminating raw food during harvesting, storage, and preparation
• Bacteria that cause diseases are known as pathogenic bacteria, leading to symptoms like nausea, vomiting, diarrhea, and abdominal cramps, potentially causing food-borne illnesses