4. Food Saftey Flashcards
Name some examples of microorganisms.
Yeasts, mould and bacteria.
What does pathogenic mean?
Disease causing
What can pathogenic microorganisms due to a person if consumed?
They can cause someone to suffer from food poisoning
What can pathogenic microorganisms do to food?
Cause it to go off
What are the conditions at which microorganisms need to be met for growth and multiplication?
Need food, warmth, moisture, optimal pH, time
How often do microorganisms multiply
Every 10-20 minutes
How can I slow or stop bacteria growing?
Change pH by picking food as the vinegar will alter the pH, prepare food as quickly as possible and chill after preparation, salt food as the salt will absorb some of the moisture, put the food in a fridge to cool it.
What is yeast an example of?
Fungi
What do moulds alter on food?
Appearance, smell and flavour
On what types of food do moulds grow on?
Fruits, cheese and bread
Why is mould visible on food
Mould is a furry growth
Why may moulds give someone food poisoning.
They excrete toxins on food
Examples of what yeasts grow on. (2) (fruits)
Plums and strawberries
What do the yeast do to the fruits?
The yeast ferment the sugars the sugars in the fruits and convert them into carbon dioxide and alcohol.
What do we classify ready-to-eat foods as?
High-risk food
What are some examples of high-risk foods?(11)
Some examples are cooked fish, poultry and meat, gravies, sauces, stocks, shellfish, cooked rice, dairy products such as cheese, milk and eggs.
What do high risk foods normally high in?
They contain lots of protein and water
Why do high-risk foods have a short shelf life?
There is a risk of bacteria multiplying rapidly.
Why are eggs not classified as a high risk food despite being high in water and protein?
We do not eat it uncooked so any bacteria will be killed in the coming process.
How to identify ‘off food’? (3)
Mould growing (on foods like bread), a sour smell (for foods like yogurt), a slimy texture (e.g chicken)
How to identify spoil-free food? (for meat)
Smelling fresh, feeling firm and appearing bright.
How to identify spoil-free food? (Fresh fish)
Smelling clean or a little salty, with red coloured gills, shiny skin and clear eyes
What are enzymes?
Enzymes are biological catalysts that increase the rate of chemical reaction. They are proteins that cause fruits to ripen or brown.
What happens in enzymic browning?
Slicing fruits and vegetables like pears and potatoes expose their insides to oxygen. The oxygen causes the fruit to brown and the enzymes in the fruit makes this process happen faster.
Why do fruits ripen?
And what does this change to the fruit?
Fruits ripen because of the enzymes they contain. Ripeness determines a fruit’s colour, texture and sweetness.
What happens in bananas in terms of enzymes?
Enzymes in bananas cause them to soften and sweeten by breaking down the starch they contain.
How to stop enzyme activity?
Enzymes function best at an optimal pH. So, introducing an acid can stop enzymes from working properly. E.g. pouring orange or lemon juice (acidic) over fruits will stop them browning
What does freezing fruit do in terms of enzymes?
Enzyme activity will slow down, however it won’t end enzyme activity
What does blanching food do to the enzymes?
It deactivates them and make sure vegetables are suitably colourful for freezing
Name all the bacteria’s that can cause food poisoning (5)
Salmonella, Campylobacter, Staphylococcus aureus, E.coli 0157, Listeria
Where can salmonella be found? (4)
Untreated eggs, unpasteurised milk and raw or uncooked poultry or meat and unwashed fruit and vegetables
How long does it take for the symptoms of salmonella to appear?
6-72 hours
How can salmonella be controlled? (4)
Washing hands after handling eggshells or uncooked meat, washing fruit and vegetables before cooking, thoroughly cooking meat, poultry and eggs and preventing cross contamination
What is the cause for the most food poisoning in the UK?
Campylobacter
We can campylobacter be found? (5)
Uncooked or undercooked poultry, unpasteurised milk, untreated water, shellfish, and mushrooms.
How long does it take for the symptoms of campylobacter to arise?
2-5 days to appear
How can campylobacter be controlled?(4)
Thoroughly cooking meat and poultry, washing salads that are prepackaged, preventing cross contamination and not washing raw chicken
Staphylococcus aureus is located where?
Live on the hair, skin and inside the noses of people/animals, can be found in handmade ready to eat foods (like sandwiches), unpasteurised milk and cooked meats
How long does it take for symptoms of staphylococcus aureus to arise?
1-6 hours
How can staphylococcus be controlled? (3)
(It’s mostly what people can do)
Keeping good personal hygiene, covering cuts when preparing food, washing hands thoroughly pre-preparation
Where can E.coli be found? (6)
Dwell in animal intestines, can be found in raw/undercooked poultry and meat, raw seafood products, vegetables that have not been washed, unpasteurised milk or products made from it and contaminated water
How long to symptoms of E.coli take to appear?
1-3 days
How is E. coli controlled? (4)
Washing hands after touching animals, drinking pasteurised milk only, preventing cross contamination and cooking meat thoroughly
Where can listeria be found? (5)
Shellfish, soft cheeses, unpasteurised milk/products made with it, ready to eat foods, unwashed vegetables
Not so fun fact of listeria?
Is able to grow in cooler temperatures like a fridge
Why is listeria bad for pregnant women?
The bacteria can cause miscarriages