Section 3 - Food Safety Flashcards
Microorganisms that can cause food spoilage
Bacteria, yeast, mould
The five conditions microorganisms need to gorw and multiply in food
Temperature
Moisture
Food(Protein)
pH
Time
Ways to prevent food spolage by microorganism multiplication
Use a fridge - Changes temp
Pickle the food - Change pH
Add salt - Change moisture
High risk foods characterisitcs
Ready-to-eat that wont be cooked
Moist and high in protein
Short shelf life
Must be stored correctly or microorganisms will grow
High risk foods eg
Cooked meat
Dairy
Graives, stocks, sauces
Shelfish
Cooked rice
Enzymes are
Biological catalysts usually made of protein
Enzymes in fruit lead to
Ripening
Enzymic browning
How to control enzymic action
Adding an acid - Enzymes denatured at different pH
Blanching veg before freezing - Destroys ripening enzymes
Mould spoils food by
Growing in a fuzzy form and leaving toxins
Yeasts spoil food by
Growing on the surface of fruit and fermenting the sugars into CO2 and alcohol.
Mould growth occurs eg
Bread , cheese
Yeast growth occurs eg
Grapes, strawberries, tomatoes
Mould is useful in making
Blue cheese. It gives a creamy texture and a tangy taste
Yeast is useful for
Raising bread. it works with water and flour to form a dough that rises
Non-pathogenic bacteria is used for
Turnign milk into cheese and yoghurt. They ferment lactose into lactic acid
Bacteria can cause
Food poisoning
Symptoms of food poisoning
Sickness, diarrhoea, stomach cramps and fever.
Extreme cases in vulnerable people can lead to death
Sources of contamination
Work surfaces and equipment
People cooking
Pests
Rubbish
5 main types of bacteria that cause food poisoning
Campylobacter
E-coli
Salmonella
Staphylococcus aureas
Listeria
Campylobacter info
Most common cause in UK
Found in raw, undercooked meat
Onset time: 2-5 days
E.coli info
Lives in intestines of animals
Most types are harmless but ecoli 0157 can caue kidney damage and death
Found in raw beef, unwashed veg and salad
Onset time:1-3 days
Salmonella info
Found in raw poultry, milk and eggs
Onset time:6-72 hours
Staphylococcus aureus
Found on the skin, hair and noses of animals and humans
Onset time:1-6 hours
Listeria info
Found in soft cheese, pate, shellfish
Can grow in cold temps
Prgenant women at higher risk
Onset time:Up to 70 days
ways of controlling bacteria
Pasteurisation of milk
Vaccination
How does pasteurisation of milk control bacteria
Milk is heated at 72*C for 15 seconds to kill of pathogenic bacteria then chilled
How do vaccinations control bacteria
Vaccinating aniamls such as hens can mae their products free of pathogenic bacteria
Cooking/reheating temperature
75*C for at least 3 mins
Kills bacteria.
Reheat food properly and only once
Chilling food temp
0C - 5C
Slows down growth of bacteria
Freezing food temp
Below 18*C
Stops bacteria growing
They go dormant but can reactivate when defrosted
Danger zone temp
5C - 63C
Bacteria grow and multiply quickly
Optimal temp for bacteria growth is 37*C
Fridge proper use
0 - 5*C
Keep foods covered to prevent contamination
Keep meats and fish at the bottom to prevent dripping
Freezers proper use
-18*C
Food should be labelled with dates
Defrost thoroughly in fridge if cooked from chilled
If cooking from frozen follow that time
Ambient foods
Food that can be stored safely at room temperature
Ambient food eg
Crisps, bread, pasta, cereal, sugar
Ambient storage conditions
Sealed container
Cool,dry place
Preservation methods for ambient foods
Freezedrying - removes moisture
Canning - Heated to kill microorganism
Vacuum packing - No oxygen
Chemicals - Changes pH
Use by date
Short shelf life foods
Not safe to eat after this date
Best before date
Long shelf life
Warning about quality
Cross-contamination occurs by
Other foods
Equipment and surfaces
People
Pests
Procedures during preperation to prevent cross-contamination
Personal hygeine
Seperating raw ingredients
Washing veg
Sanitising equipment and surfaces
Defrost food fully
Personal hygiene procedures
Washing hands
Wearing clean apron
Keep hair away
Remove jewlery
Cover all cuts
Procedures during cooking to prevent cross-contamination
Cooking food at correct temp for correct time
Make suree food is cooked through
Test temp using a probe
How to use a temp probe
Sterilise before and after use
Insert into thickest part of food
Leave probe in until temp stabilises
Check it reaches at least 75*
Procedures during serving to prevent cross-contamination
Serve hot food straight away or keep above 63* for maximum 2 hours
Cool down food within 90 minutes if served cold
Keep food covered to keep pests away
Avoid wasting food
