Bacterial Contamination Flashcards
1
Q
What can contaminate food causing food spoilage?
A
Yeast, mounds, bacteria and enzymes
2
Q
What can enzymes cause
A
Ripening of fruit and veg
3
Q
What does ripening do
A
Changes colour and flavour of fruit and veg
4
Q
What are yeast, bacteria and moulds
A
Microorganisms
5
Q
What do yeast, mound and bacteria need
A
Food, moisture, warmth and time to grow
6
Q
What will microorganisms do
A
Spoil food overtime
7
Q
What is yeast
A
Tiny single called fungi
8
Q
How does yeast reproduce
A
By budding
9
Q
What causes fermentation
A
Yeast and warm water
10
Q
What is mould
A
Fungi which produces thread like filament which spreads mound extracting nutrients
11
Q
What is the ideal growth conditions for mould
A
20 - 30 degrees
Damp air
Warm temperature
12
Q
What is bacteria
A
A single celled microorganisms
13
Q
Where is bacteria found
A
Everywhere
14
Q
What are the 3 groups of bacteria
A
Harmless bacteria
Pathogenic bacteria
Food spoilage bacteria
15
Q
Can bacteria be seen
A
Yes button,y through a very powerful microscope
16
Q
What are enzymes
A
Biological catalysts which speed up reactions
17
Q
What do enzymes cause
A
Browning in foods - enzymic browning
18
Q
How are enzymes destroyed
A
By heat or acids
19
Q
What happens to fruit and veg during preparation
A
It turns brown
20
Q
How do you prevent enzymic browning
A
Use acid which denatures the enzyme
21
Q
What do enzymes use to spoil food
A
Oxidation
22
Q
What does oxidation do
A
It results in the loss of vitamin b and c from fruit and veg during prep and cooking
23
Q
Name 2 ways in which enzymes may spoil food
A
Catalase and peroxidase -
24
Q
What conditions do microorganisms need to grow
A
Food
Time
Warmth
Moisture
25
Name 2 foods yeast may spoil
Jam and honey
26
What happens when yeast multiplies
The food develops off flavours and appears fizzy with green/ blue areas across the product
27
How do you prevent mould growth in bed
Keep in a cool dark place
28
What is the difference between the 3 types of bacteria
Pathogenic - causes food poisoning
Food spoilage - breaks down food. Not harmful
Harmless - only dangerous in large amounts. Found in small intestine
29
What do high risk foods have in common
They provide a place for bacteria to live, grow and thrive e.g cooked meat, fish and rice
30
How do u blanch foods and why do we blanch them
It kills enzymes. Boil veg and then freeze them
31
Where are enzymes found
Naturally found in food
32
What happens when enzymes react with oxygen
They brown. Enzyme starch - sugar ~ ripens them but eventually spoils them
33
How can you prevent food spoilage
Freezing, chilling, jam making and pickling
34
How does freezing prevent food spoilage
-18 degrees
Makes microorganisms become dormant
Water changes so ice so there is no moisture for them to grow
Microorganism growth is increased when defrosted
35
What foods can u freeze
Meats, fish, poultry, vegetables and some fruit
36
How does chilling prevent food spoilage
Below 5 degrees
| Microorganisms and food spoilage slowed down but not stopped
37
What foods can you chill
Ready to eat products, salads, dairy products
38
How does jam making prevent food spoilage
Boiled to destroy microorganisms
| High concentration of sugar reduces microorganisms activity and acts as a preservative
39
What foods can u use for jam making
Fruits
40
How does pickling prevent food spoilage
Boiled to destroy enzymes
| Acidic conditions prevent growth of microorganisms because the pH is to acidic
41
What foods are suitable for pickling
Fruit and veg
42
What foods are made with mould
Brie, camamber and Stilton cheese
43
What does mould do to cheese
Gives distinctive colours and flavours
44
What is mould used for
To ripen foods
45
What is yeast used to produce
Bread, beer and wine
46
What is yeast used for
Used to ferment grapes into wine and hops into beer
47
What does yeast do to glucose and what does it make
Breaks down glucose and makes alcohol and co2
48
Fill in the gaps
| Glucose —- alcohol + ? + energy
Glucose (sugar) ——— alcohol +co2 +energy
| Yeast
49
What does yeast rise
Bread, crumpets, donughts and ice buns
50
What does co2 and alcohol make
Fizz
51
What does bacteria do
Gives the correct level of acidity and gives cheese its moisture
52
What does bacteria give cheese
It’s smell, taste, texture and the holes in cheese
53
What does bacteria give yoghurt
Taste and texture
54
What does probiotic drinks have
Health benefits
55
What is the role of bacteria in cheese
Sours the milk, changes the lactose in milk into lactic acid, lowers pH and starts off the cheese making
56
Name the sources of bacterial contamination
Raw food, work surface and equipment,food handler, pest and waste food and rubbish contamination
57
How do you control raw food contamination
Cook the food thoroughly, be carful when storing and handling the food
58
Examples of sources raw food contamination
Meats, poultry, eggs, shellfish, rice and vegetables
59
How do you control work surface and equipment contamination
Clean work surface, clean utensils with hot soapy water, colour code equipment, disposable cloth and antibacterial spray
60
Examples of work suraface and equipment contamination sources
Raw meat juices touch equipment
61
How do u control food handler contamination
Use tongs/ utensils to pick up food, avoid touching parts of utensils and don’t lick your fingers
62
What are the sources of food handler contamination
When you touch food and use the sam utensils twice to try food
63
How do you control pest contamination
```
Keep work surface clean
Wash up straight away
Don’t leave food overnight
Empty bins regularly
Don’t let domestic pets in the kitchen
```
64
Name examples of pest contamination sources
Flies, insects, birds, mice and rats
65
How do you control waste food and rubbish contamination
```
Only use bins with lids
Thick bin bags
Wash bins regularly
Foot operated bin
Empty bins regular
```
66
Name sources of waste food and rubbish contamination
Bacteria multiplied in food waste
67
Where is campylobacter found
Human and animal gut, sewage, water and raw meat
68
Where is E.coli found
Animals, sewage and untreated water
69
Where is salmonella found
Soil, water, sewage and people
70
Where is listeria found
Intestines of ill people, animals, birds, raw meat, unpasrured milk, imported poultry and eggs
71
Where is staphylococcus aureus found
Skin, hair, noses and throats of people ho are infected with bacteria
72
What temperature is the danger zone
5 - 63 degrees
73
How does bacteria grow under 5 degrees
Very slowly or not at all
74
What happens to bacteria above 63 degrees
It doesn’t grow
75
What temperature does bacteria grow fastest
37 degrees
76
What foods can be in the danger zone
Non perishable foods
77
What is the temperature of the cupboard
17 - 20 degrees
78
High risk foods are usually ...
Ready to eat
79
What temperature should hot food be
63 degrees and above
80
What temperature should cold food be
5 degrees and below
81
What should you do with prepared food
Keep it out of the danger zone
82
What temperature should the fridge be and why
0-5 degrees as microorganisms grow slowly
83
What should go on the top shelf of the fridge
Cheese
84
What shelf should eggs go on
2nd shelf
85
Where should cooked meat go
3rd she,f of the fridge
86
Where should fresh meat go
4th shelf of the fridge
87
Wheat should go on the last shelf of the fridge
Salad vegetables
88
Name 5 advantages of using the freezer
Makes bacteria inactive, most foods can be frozen, simple and reduces waste, nutrients, flavour and colour are retained, makes seasonal foods available all year round
89
Name 4 disadvantages of freezing
Most bacteria survive the freezing process, once defrosted bacteria will multiply again, texture of food will deteriorate over time, food can ‘burn’ if not wrapped correctly
90
Why is it important to check use by and best before dates
Use by dates tell you when it is safe to eat.
Best before date relates to the sensory quality
It’s safe to eat after the best before date but not safe to eat after the use by dates
91
Why is it important to be careful defrosting of frozen food
Defrost thoroughly with some foods otherwise bacteria may survive during cooking causing food contamination but some foods don’t need to defrost before cooking
92
Why is it important to cover food
Prevents contamination from pests and dust and it can’t land in the food and prevents it from drying out
93
Why is it important to have good personal hygiene
Clean your nails and keep the short
Wash hands
Dry with disposable bacteria to reduce spread of bacteria
94
Why is it important to wash dishcloths regularly
Used dishcloths carry bacteria which when used repeatedly doesn’t clean the surface leading to bacterial contamination
95
Why is it important to clean work surfaces
So it’s free from bacteria
| Use hot soapy water and anti bacterial spray to destroy the bacteria
96
Why is it important to separate raw and cooked food and use separate utensils
Can lead to contamination if the cooked food comes into contact with raw food
Colour code utensils to prevent spread of bacteria
97
What do you need to do to a temperature probe before use
Clean and disinfect it
98
Where do you insert the temperature probe
In the thickest part
99
What does the temperature of the food need to have reached so you know it’s cooked
75 degrees
100
What do you need to do to the probe after use and why
Clean and disinfect it to avoid cross contamination
