Bacteria Flashcards
Where is bacteria found
Air
Soil
Intestines of animals
Moist lining of mouths
Noses and throat
Furnaces of our body
On plants
What is binary fission
When the nuclear reproduces itself and divides into 2 seperate parts then the rest of the cell divides producing 2 daughter cells of eqaul size this is called time under optimum conditions
How long does it take for bacteria to divide
10 mins some 20
What do spores enable bacteria to do
Survive
What are spores
Hard resistant bodie formed by some bacteria when they are unable to obtain materials needed for growth can survive in unfavourable conditions for very long periods of time they are heat resistant are cold resistant many are resistant to disenfectant some in the right conditions germinate producing new bacteria cell spores for bacillus and elstrodium
What are pathogenic bacteria
They are bacteria which are harmful and can cause food poisoning and food borne diseases
What do pathogenic bacteria include
Bacillus, escherichia coli ( E-coli)
Salmonella
Camplybacter
What are the 4 conditions for bacteria to grow
Food moisture warmth time
What can bacteria not grow in
Vinegar
Alkaline conditions
What can bacteria not grow in
Vinegar
Alkaline conditions
What are high risk foods
Foods which are moist warm and high in protein
How do you minimise risk of bacteria
Bacteria multiply rapidly 1 can become 1 billion in less than 7 hours.
You need to reduce time food is kept in the danger zone
Keep time between buying it and storing it in fridge or freezer
Ensure it is eaton within use by date
Prepare as quick as possible
Cook high risk food for long enough
Eat food as soon as it is made
Food kept warm should be over 63 anything left over 2 hours should be thrown away
What happens at 100 degrees
Bacteria destroyed boiling point of water
What happens at 75 degrees
You need to reheat the food for 30s to ensure it is safe to eat
What happens at 70 degrees
You need to reheat food for 2mins to ensure it is safe to eat
What happens at 63 degrees
Bacteria start to die
What happens at 63 degrees
Bacteria start to die
What happens at 37 degrees
Body temp ideal for bacteria to grow
What happens at 8 degrees
Legal fridge temp must be below
What happens at 0-5 degrees
Bacteria multiplies slowly
What happens at -18 degrees
Freezer temp bacteria dormant
What temp does fridge legally have to be
It has to legally be under 8 but usually under 5
What is the hot holding temp
72 degrees for 2 mins kills harmful bacteria
What temp should reheated food reach
75
What can you check a temperature of food with
Temperature probe or an infra red laser thermometer
How do you control how much moisture is in food
By dehydration removing water E.g dried milk
High sugar content makes less water available E.g jam
Salt removes water by osmosis E.g bacon
Freezing turns water into solid so unavailable
Pickling the water is replaced with vinegar
What are some high risk food s
Ready to eat sandwiches
Moist yoghurt
High in protein cottage pie
Require strict time and temp control meat pie
Raw fish dairy products cooked meat poultry shellfish and seafood gravies stocks sauces soup stews egg products cooked rice
What is oxygen removal
Some bacteria need oxygen to produce aerobic respiration manufacturers use a vacuole to remove oxygen replace with less active gas
What is ph control
Bacteria grow best in neutral ph between 6.6 and 7.5 they cannot survive in food with a ph less than 4.5
What are the classifications of bacteria
Pathogenic cause illnes
Helpful used to make cheese and yoghurt
Spoilage cause food to perish or rot
What is the definition of food poisoning
An acute illness usually and usually fairly short cause y eating food that is comtaminated by microorganisms or poisons
What kind of people are more likely to get food poisoning
Babies and young people immune system immature
Pregnant
Elderly
People with illnesses HIV AIDS make immune weaker
What are the 8 different types of bacterium
Bacillus cereus
Campylobacter
Clostridium botulinum
Clostridium perfringens
E. coli
Listeria
Salmonella
Staphylococcus aureus
What are moulds a form of
Fungi
How do moulds move
They are carried in the air and settle on food
What is mould growth
The growth of a filament a tough mass which you can see
How do moulds die
By heat
What do moulds thrive in
Acidic foods such as fruit tomatoes jam jellies
What are yeasts
Single called fungi
How do yeast reproduce
By budding they use sugar to grow and produce co2 known as fermentation
How are yeasts killed
Heat
What happens to yeast when it is could
They become dormant
What are the perfect conditions for mould
Moist food that is room temp and has time to reproduce
What do staphylococcus aureus and bacillus cereus produce what does this cause
Toxins in food they cause vomiting and symptoms are quick to come on
Where do campylobacter jejuni salmonella E. Coli clostridium perfringens originate and what does it cause
Gut it causes diarrhoea and are slower for symptoms to come out
Under what conditions do bacteria reproduce
They need time the right temp moisture food good ph level and oxygen
Why are people getting more food poisoning
Increase in ready to eat food
Incorrect storage temperature
Not cooked over 75°C for 30 seconds
Incorrect reheat temperature
Not prepared correctly – cross contamination
Paul personal hygiene
What conditions do yeast grow
Warmth food time moisture
What is food spoilage
Means that the original nutritional value, texture or flavour of food is damaged, the food becomes harmful to people and unsuitable to eat
What is moisture loss
When fruit or veg are harvested they continue to respire so lose water through the leaves and skin E.g lettuce
What is infestation
Invasion by insects and rodents which accounts for huge losses in food stock E.G pears apples fruit and veg
What is low-temperature injury
The internal structure of the food are damaged by a very low temperature E.G 0 to 1°C in the fridge E.G salad leaves cucumber and those are very high water content
What are enzymes
Enzymes are proteins which speed up chemical reactions they are inactive until food is harvested or slaughtered once activated they start to break down the tissues and components of food they cause ripening by turning starch into sugar they are destroyed by acids in heat atmospheric oxygen can react with some food components which may cause rancidity or colour changes
What are some natural decay ways of food spoilage
Moisture loss, infestation, low temperature injury, enzymes
What is the best way to prevent enzymic browning
The best way is put salt on it but you will have to wash it
What is the best way to prevent enzymic browning
The best way is put salt on it but you will have to wash it
What are 6 ways to prevent food spoilage
Store in appropriate place
Check fridge temperature
Cover food in tin foil or cling film
Wash soil of fruit veg
Wash hands before handling food
Eat before use by date
What are 5 negative affects of food spoilage
Wilt lettuce
Colour change
Contaminated
Mould Rot
Nutrition loss
What are 5 posotive effects of food spoilage
Cheese
Yoghurt
Cider
Bread
Wine
What are 3 helpful micro organism and what are they used in
Mould soft cheese Stilton Brie
yeast wine cider
Bacteria cheese yoghurt
What is a perishable food
Spoil very quickly and must be kept in fridge E Duchy milk meat fish dairy and soft fruit
What does use by date mean
The date by which food should be eaten to ensure it’s safe
What does best before mean
Apply to nonperishable food aid Archie biscuits crisps food will be in its best conditions start to change but not unsafe
What does display until mean
The date food should be sold normally 2 to 3 days before use by date
What does stock rotation mean
Use old food before new food
What visual checks can you perform when buying food
The use by date
What is a packet is open
If the tin has dents in it
If it’s fresh looking
Can’t be wrinkled
No bruises
No holes
How do you wash your hands
Step one what your hands with warm water step to soap and scrub for 20 seconds step three rinse under clean running water step for dry completely using a clean cloth or paper towel
When should you wash your hands
After using the toilet
After sneezing glowing nose and coughing
After touching a cut or saw
Before touching raw meat fish or poultry and eggs
Before handling food
What is meant by the term clean as you go
Clean the area and utensils you have been working with as you prepare the food to avoid build up of mess and leads to better hygienic conditions
How do you keep yourself clean when preparing food
Where clean aprons only remove jewelry cover cuts and wounds with a blue plasters or dressing
What colour plasters are used and why are they so important
Blue because if they end up in the food they are much easier to see in skin colour plasters so you can get them out
How should fruits and vegetables be cleaned
Remove and discard outer leaves rinse under water rub briskly to remove dirt and surface microorganisms don’t use soap or detergent drawer was clean cloth cutaway bruises
Should raw meat be washed before use
No as it increases the danger of cross contamination spreading campylobacter on the surfaces
Should raw meat be washed before use
No as it increases the danger of cross contamination spreading campylobacter on the surfaces
Define cross contamination and the major causes of it
The process by which bacteria are transferred from one area to another
Main causes humans rubbish pets and animals raw meat and poultry
What colour boards should be used for raw meat raw shellfish and cook meat
Raw meat – red
Raw shellfish – blue
Cooked meat – yellow
What colour boards should be used for vegetables fruit and salad bakery and dairy
Vegetables – brown
Fruit and salad – green
Bakery and dairy – white
What are purple boards used for
Allergens
What does direct contact cross contamination mean
Blood and juices from raw food passes directly onto other foods are you dodgy raw meat dripping in the fridge
What does indirect contact cross contamination mean
Bacteria is transferred during handling and for preparation E.g on hands dirty equipment clothes etc
What is physical contamination
Foreign bodies in the food that should not be is a dodgy metal, hair, nails, insects, jewellery
What is chemical contamination
Cleaning products, pesticides, natural toxins are present in the food
What is the danger zone
5-63
Why is it vital to wash your temperature probe after each temperature check
So that you don’t cross contaminate some other foods
What does it mean for juices must run clear
When the juices come out of (especially meat) the food they should be clear I’m not pink
What is the two hour rule
Refrigerate perishable foods so total time at room temperature is less than two hours
Define the term perishable foods
Foods which are likely to spoil or become unsafe if not refrigerated E.G meat poultry fish eggs tofu dairy products cooked pasta rice vegetables
What is the 90 minute rule
Hot food that is an eaten straight away should be called under 8°C within 90 minutes to reduce time in danger zone
Explain how to effectively cool food
Call Inshallah containers limit debt for food
Sitting bowl of cool water
Blast chiller
Explain how to safely thaw food
Plan ahead to defrost food
The best way to thaw perishable food is in the fridge
What should you do if you have leftovers
Should be called as quickly as possible within 90 minutes separating food into smaller containers can help they need to be reheated piping hot leftovers should not be reheated more than once used within one to 4 days
What are fridge rolls
Keep door closed as much as possible under 5°C legally under 8°C wait for food to cool down before is placed in the fridge do you know overload if the fridge is full of the cooler will not circulate around the food keep food covered to prevent cross contamination and moisture loss clean to removed spills and food deposits whenever they occur to prevent cross contamination of food
What are freezer rules
Keep under -18°C is not place hot food is in the freezer or leave the door open for extended periods do you not overload the freezer store food with the label showing the contents and the date wrap food to prevent it drying out only freeze food at its best condition keep freezer clean removing spills and food deposits want to occur never refreeze defrosted food as this increases the growth of bacteria
