Topic 3: Food Safety Flashcards
what does it mean when food deteriorates?
starts to decay and lose freshness
what are microorganisms?
tiny living things such as bacteria, yeast and moulds which cause food spoilage, only be seen through a microscope
what are enzymes?
proteins that speed up chemical reactions
what is bacteria?
single-celled organisms present in the air, soil, on animals and humans
are all bacteria harmful?
no
what is pathogenic bacteria?
harmful bacteria which can cause food poisioning
what are high-risk foods?
foods that are the ideal medium for the growth of bacteria or microorganisms
how do bacteria divide?
binary fission
what conditions can bacteria grow in?
- neutral pH
- more active in the danger zone (5-63ºC)
- can form spores that can lie dormant
- can aerobically and anaerobically
are all mould harmful?
no. some can be used by manufacturers to produce specific flavours and textures
what can be said about moulds?
- visible to the eye
- reproduce by producing spores
- harmful only when they produce mycotoxins
what conditions are needed for mould to grow?
- oxygen
- quickly in moist conditions
- slowly in dry conditions
- food that may be dry, moist, acid, alkaline or has salt or sugar concentration
what is food spoilage?
damage to food caused by the natural decay of food by contamination by microorganism
what conditions are needed for yeast to grow?
- warm moist conditions with food
- does not need oxygen
how can enzymatic browning be reduced?
- high temperatures, blanching vegetables in hot water
- acidic conditions, lemon juice
are all bacteria harmful?
no, some used in manufacturing for cheese and yoghurt
what visual checks do you need to carry out before buying food?
- food looks fresh
- food is within date of either best before or use by
- packaging is not damaged
what is the best before date?
used on low-risk foods, is best quality before date
what are low risk foods?
foods that have a long shelf life, such as dried roots
what is shelf life?
how long a food product can be kept safely and remain of high quality
what is use by date?
used on high-risk foods, should be consumed before date
what temperature should a domestic refrigerator be?
between 0-5ºC
how do you use your fridge sensibly?
- avoid opening door regularly - warm air enters when you do
- avoid putting in hot food, raises the temperature and fills the inside with steam
- cover food
- maintain a consistent temperature, increase temp could lead to bacterial growth
- keep raw and high risk foods away from other foods, store on bottom shelf
what temperature should a domestic freezer be?
-18ºC
what happens when food is thawed?
structure of food is damaged and sometimes loss of colour, flavour, texture and nutritional value
what should u never do once food is thawed?
refreeze the food as bacteria will grow quickly as the cells have been damaged
what is freezer burn?
greyish white marks appear on food when it has been packaged badly. The food dehydrates, and although safe to eat, will change colour, texture and flavour
what are the rules for food hygiene?
1) wash hands thoroughly before handling food
2) keep raw and cooked food separate
3) wear clean protective clothing
4) keep all working surfaces and utensils clean
5) cover and cool all foods rapidly and refrigerate it quickly
6) do not put hot food in the refrigerator as it will raise the temp of other foods
7) keep pets away
8) take care of disposal, keep bins covered and wash them regularly
what must you do to prevent cross contamination?
- raw and cooked foods from touching each other
- blood and juices of raw foods dripping onto other cooked foods
- bacteria being transferred during handling and preparation
why has there been an increase in cases of food poisoning?
- more people are using microwaves often mean that food is not defrosted or cooked to the correct temperature
- increased use of cooked-chill foods which are high risk foods
- foods not stored at the correct temperature
- food not prepared correctly
- poor personal hygiene practices
- hot food not kept above 63ºC
- not reheating food at the correct temperature
what are the causes of food poisoning?
- not thawed properly
- preparing food too far in advance
- undercooking high-risk foods
- not allowing foods to cool before putting them in chill cabinets - 90 mins to chill below 8ºC
- not reheating food to correct temperature
- keeping hot foods below 63ºC
- leaving foods on display at room temperatures for longer than a maximum safe period
- not checking temperatures accurately
what are the sources of salmonella?
poultry, eggs, meat
what are the sources of staphylococcus aureus?
food handlers
what are the sources of clostridium perfringens?
raw foods, such as fruit and veg
what are the sources of bacillus cereus?
cereals, especially rice
what are the sources of campylobacter?
infected animals, birds, unpasteurised milk
what are the sources of listeria?
raw, processed or cooked foods
what are the sources of E. coli?
cattle, raw meat and raw milk
how long should you cook food at 70ºC?
2 minutes
how long should you cook food at 75ºC?
30 seconds
how long should you cook food at 80ºC?
6 seconds
how long should you cook food at 86ºC?
instant reading
what are examples of high-risk foods?
raw fish
dairy products
cooked meat and poultry
shellfish and seafood
eggs
cooked rice
what are examples of low-risk foods
high acid content foods
high sugar content foods
unprocessed raw vegetables
sugar based confectionery
