food spoilage, contamination, poisoning

Question 1

What are the causes of food spoilage and can you give a description of them? (6)

Answer 1

1. microorganisms - bacteria, moulds, yeasts, fungi
2. enzymes - speed up the process of decay to enable bacteria to absorb nutrients and reproduce
3. insects and rodents - leave behind bacteria, urine and faeces
4. chemical reactions - the reactions between the food, oxygen and moisture
5. environmental factors - such as warmth, pH, oxygen, and moisture
6. time - the speed of spoilage is determined by hygiene, correct storage and temperature

Question 2

define autolysis

Answer 2

self destruction, caused by enzymes present in the food

Question 3

define microbial spoilage

Answer 3

caused by the growth of micro-organisms e.g. bacteria, yeasts and moulds

Question 4

what is pathogenic bacteria

Answer 4

harmful bacteria

Question 5

define cross-contamination

Answer 5

the transfer of bacteria from one source to another. usually raw food to ready to eat food but can also be the transfer of bacteria from unclean hands, equipment, cloths or pests.

Question 6

What is the role of environmental health officers (EHO’S)?

Answer 6

they monitor all food businesses to check that food safety regulations are being followed.

Question 7

What happens if EHO’S find poor food safety?

Answer 7

the business will be warned, fined, or jailed depending on how serious the problem is

Question 8

why does the correct temperature play an important part in food spoilage?

Answer 8

correct temperatures play an important part because they will help slow down bacterial growth and food spoilage

Question 9

what temperature should each of the following be stored at?
chilled foods, frozen foods, ambient foods, hot held foods.

Answer 9

chilled foods - fridge 0-5 degrees Celsius
frozen foods - freezer -18 degrees Celsius
ambient foods - stored on a shelf or cupboard at room temperature
hot held foods - 63 degrees Celsius

Question 10

what type of conditions do bacteria need to grow and multiply?

Answer 10

bacteria need warm conditions to grow and multiply

Question 11

what’s the ideal temperature for bacterial growth?

Answer 11

30-37 degrees Celsius

Question 12

what is the bacterial growth danger zone?

Answer 12

5-63 degrees Celsius

Question 13

what happens to bacteria at very cold temperatures?

Answer 13

bacteria become dormant and cannot grow or multiply - but do not die

Question 14

at what temperature are most bacteria destroyed?

Answer 14

63 degrees celsius

Question 15

what are the three main ways food can deteriorate and can you explain what happens during it?

Answer 15

ripening - this will continue until he food as become inedible e.g. banana ripening
browning - enzymes can react with air causing certain foods to discolour e.g. apples
oxidation - loss of nutrients, such as vitamin C from food, e.g. over boiling green vegetables

Question 16

define the term bacteria

Answer 16

single celled micro-organisms which are present naturally in the environment

Question 17

define the term yeast

Answer 17

single celled fungi

Question 18

define term mould

Answer 18

fungi which grow as filaments on food

Question 19

what are the three ways food can become contaminated?

Answer 19

bacterial, chemical and physical

Question 20

give an example of chemical contamination

Answer 20

chemicals fro the farm, cleaning products used in the processing plant and fly spray used in the kitchen

Question 21

give an example of physical contamination

Answer 21

soil from the ground when harvesting , a loose bolt from a processing plant when packaging, a hair from a chef in the kitchen

Question 22

give an example of bacterial contamination

Answer 22

bacteria can be transferred onto food through cross-contamination, via equipment, people or pests, or can be naturally present in the food.
some bacteria can produce toxins which can cause food poising.

Question 23

state the conditions micro-organisms need to survive

Answer 23

temperature, moisture, food, time, oxygen, pH level

Question 24

name high risk foods

Answer 24

meat, dairy, eggs, shellfish and seafood, prepared salads and vegetables, cooked rice and pasta

Question 25

true or false?
bacterium can divide in two every 10-20 minutes

Answer 25

true

Question 26

who are at a higher risk of food poisoning?

Answer 26

elderly people, babies, and anyone who is ill or pregnant

Question 27

what are the symptoms of food poisoning?

Answer 27

feeling sick, being sick, diarrhoea, abdominal pain

Question 28

what are the sources of campylobacter?

Answer 28

raw and uncooked poultry, unpasteurised milk, contaminated water.

Question 29

what are the signs and symptoms of campylobacter?

Answer 29

onset 2-5 days
fever, headaches and dizziness for a few hours, followed by abdominal pain

Question 30

what are the sources of E Coli 0157?

Answer 30

raw and uncooked meat and poultry, unwashed vegetables, contaminated water

Question 31

what are the signs and symptoms for E Coli 0157?

Answer 31

onset 3-4 days
diarrhoea (might contain blood), can lead to kidney failure of death

Question 32

what are the sources of listeria?

Answer 32

unpasteurised milk and dairy products, cook-chill foods, pâté, meat, poultry and salad vegetables

Question 33

what are the signs and symptoms of listeria?

Answer 33

onset 1-70 days
ranges from mild flu-like illness to meningitis, septicaemia, pneumonia.
During pregnancy may lead to miscarriage or birth of an infected baby

Question 34

what are the sources of staphylococcus aureus?

Answer 34

humans: nose, mouth and skin
untreated milk

Question 35

what are the signs and symptoms of staphylococcus aureus?

Answer 35

onset 1-6 hours
severe vomiting, abdominal pain, weakness and lower than normal temperature
this usually lasts 6-24 hours