Food Safety

Question 1

What is bacteria and how are the useful in food?

Answer 1

• Bacteria are single-celled organisms that are able to reproduce rapidly. They are also called microorganisms.
• Bacteria are sometimes useful and are used in cheese-making and in yogurt.
• They are sometimes harmful (pathogenic) and can cause food poisoning.

Question 2

What is the conditions for growth of bacteria - TEMPERATURE?

Answer 2

• Bacteria generally multiply between 5°C and 63 °C.
• The average ideal temperature for rapid bacterial multiplication is 37°C, which is body temperature.

Question 3

What are the conditions for growth of bacteria - MOISTURE?

Answer 3

Bacteria need moisture to live and multiply.

Question 4

What are the conditions for growth of bacteria - TIME?

Answer 4

• Under optimum conditions, bacteria will — multiply every 10-20 minutes, so within seven hours one bacterium can become one million.

**To control bacteria multiplying:
**
- eat food as soon as possible after making/cooking
- if food is not being eaten straight away, cool down as quickly as possible (within 90 minutes is recommended) and store in the fridge or freezer. A blast chiller will cool food more quickly than the recommended 90 minutes.

Question 5

What are the conditions for growth of bacteria - NUTRIENTS?

Answer 5

Bacteria can multiply to large numbers on high-risk foods such as meat, poultry, fish, eggs and milk. These are all high-risk foods.

Question 6

What are the conditions for growth of bacteria - pH LEVEL?

Answer 6

• Bacteria grow best at a neutral pH level, between 6.6 and 7.5.
• Bacteria are unable to survive below pH 4.5.
• Vinegar (acetic acid) has a pH of 3.5.

Question 7

What is yeast?
What is the conditions of yeast to stay alive?
What is yeast used for in food?

Answer 7

1. Yeast are single-celled plants found in the air and on skins of fruit. Yeast spoils the taste of food but is not harmful.
   2.
   * It grows only on sugary foods, but not in sugar concentrations above 50% (jams should be made with 60% sugar).
   * It can survive without air.
   * It can’t grow at low temperatures or survive in vinegar.
   * It is destroyed at temperatures above 70 °C.
2. Yeast is a very helpful organism. It is used in baking bread, where carbon dioxide is used as a raising agent, and in wineub making and brewing.

Question 8

What is mould?
What is the conditions of mould to stay alive?
What does mould mean on food?

Answer 8

1. Moulds are a type of fungus, that settle on food and grow into a visible plant. Moulds grow on many foods, such as bread, cheese and meat.
2. • They like slightly acid conditions.
   • They need moisture and warmth (20 °C-40 °C), but are destroyed by heat <70 °C.
   • Moulds can survive in the fridge but not in the freezer.
3. Mould on food is a sign that it is not very fresh or has been stored incorrectly. Some mould can result in allergic reaction and respiratory difficulties.

Question 9

What can enzymes do to food?
How can you prevent this?
What are enzymes?

Answer 9

1. The cells break open, the enzymes escape and react with other parts of the food.
   Soft spots appear on fruit and vegetables and makes meat smell and taste bad.
2. Denaturing the enzymes can help to preserve the food, e.g. through heat, use of acids, strong alkalis or salt.

3.Enzymes are chemical catalysts that are found in all cells.
Enzymes break down plant and animal tissues, causing fruit to ripen, meat to tenderise and enzymic browning (also known as oxidation) to speed up.

Question 10

How are microorganisms used in the production of cheese?

Answer 10

• It would be impossible to make cheese without a starter culture.
• As the culture grows in the milk, it converts the sugar lactose into lactic acid, which ensures the correct level of acidity and gives the cheese its moisture.
• As the cheese ripens, the culture gives it a balanced aroma, taste, and texture.
• Choosing the right mixture of culture is essential for a high- quality cheese.

Question 10

What are ways to prevent oxidation (enzymic browning)?

Answer 10

• Adding lemon juice (an acid) to a fruit salad prevents browning.
• Blanching vegetables before freezing prevents discolouration.
• Removing air by immersing potatoes in water will prevent browning.
• Refrigeration or freezing will slow down browning.
• The removal of moisture (dehydration) will prevent browning, however it is a slow process and the browning reaction is quick.

Question 11

How is blue cheese made?

Answer 11

**To make blue cheese:
**
-the cheese is treated with a mould
- as the cheese matures, the mould grows
-this creates blue veins within the cheese, giving the
–cheese its characteristic flavour, e.g. stilton and roquefort.

Question 12

How is soft ripened made?

Answer 12

**To make soft ripened cheese:
**
-P. camemberti is allowed to grow on the outside of the cheese, causing the cheese to age from the outside in, forming a soft white crust and runny inside e.g. brie and camembert.

Question 13

How is rind - washed cheese made?

Answer 13

**To make rind-washed cheeses:
**
-rind-washed cheeses also ripen inwards but they are washed with brine and other ingredients, e.g. beer and wine, which contain mould
-this makes them attractive to bacteria, which adds to the flavour, e.g. limburger.

Question 14

How are microorganism used in the production of yoghurt?

Answer 14

• In yoghurt, the culture is responsible for the taste and texture of the final product.
• In recent years probiotic cultures have become popular in dairy products because of their health benefits.
• Probiotic cultures are carefully selected strains, and there is good evidence that they help improve digestion, safeguard the immune system, and keep the body’s intestinal flora in balance.
• Probiotic cultures are classified as a functional food.

Question 15

How are microorganisms used in the production of meat?

Answer 15

• Meat starter cultures are used to make dried, fermented products such as salami, pepperoni, chorizo and dried ham.
• Lactic bacteria develop the flavour and colour of the products. .
• A wide variety of moulds are used to ripen the surface of sausages, preserving the natural quality of the product and controlling the development of flavour.

Question 16

What is yeast used for in food production?
What does it require to grow?
Hoe is it used in bred making!

Answer 16

1. Yeast is used in bread-making as well as in making beer and wine.
2. Yeast is a microorganism.
   Yeast requires sugar to grow.
3. In bread making, yeast will:leaven the dough by producing CO2 through fermentation and its enzymic action on other ingredients, create a stretchy dough contribute to the flavour of the bread.

Question 17

Whee can bacteria be found?

Answer 17

Bacteria can be found everywhere, including raw food, people, air and dust, equipment and utensils, soil, pests, water and food waste.

Question 18

What are the dangers of bacteria?

Answer 18

• It is essential to control the conditions that allow bacteria to multiply and cause illness, e.g. stick to strict time and temperature controls.
• You can become ill if you eat food that is contaminated by certain bacteria (pathogens) and viruses.
• Kitchens provide the ideal conditions for bacteria growth.
• Bacteria are microscopic. You cannot tell if a food is contaminated by just looking at it.

Question 19

What is food poising caused by?

Answer 19

Bacteria multiplying in food.

Question 20

Give examples of food poising, what food is affected, the symptoms, onset and any special notes about it? PATHOGENIC BACTERIA

Answer 20

Salmonella - Raw meat:eggs, seafoods, dairy products - Diarrhoea, vomiting, fever - 12-36 hours - May be fatal to the elderly and babies. Found in human and animal excrete.

Staphylococcus Aureus - Cooked sliced meat, dairy products, anything touched by hand - vomiting, diarrhoea, abdominal pain - 1-6 hours - Present in nasal passages throat and skin. Associated with dirty food handlers . Good personal hygiene is crucial.

Clostridium perfingens - Raw and cooked , meat and meat products - Nausea, Diarrhoea , Abdominal pain - 8-22 hours

Clostridium Botulinum- Incorrectly canned meat, fish or vegetables - Paralysis, difficulty breathing, double vision, nausea, vomiting - 12-48 hours - Rare

Bacillus cereus - Cooked rice ,pasta and cereal foods - Nausea, Vomiting, Diarrhoea - 1-6 hours

Question 21

What is food borne diseases caused by?

Answer 21

Pathogenic microbes (bacteria and viruses) carried on food. These microbes do not multiply in the food but in the person who has eaten the food.

Question 22

Give examples of food poising, what food is affected, the symptoms, onset and any special notes about it? PATHOGENIC MICROBES

Answer 22

Escherichia + Coli (E-coli) - Raw meat, untreated milk and water -Vomiting, blood in diarrhoea, kidney damage or failure - 12-24 hours - Causes gastri-enteritis in humans

Listeria Monocytogenes - Soft cheeses, Pate, Unpasteurised milk, Undercooked meat, Incorrectly heated cook-chill meats - A range of symptoms from mild flu - like symptoms to septicaemia, meningitis and pneumonia - No specific time - Can cause miscarriage, premature labour and birth.

Campylobacter - Meat, Shellfish, Untreated water, Washing raw poultry - Diarrhoea, headache, fever, abdominal pain - 1-11 days - Easily transmitted between humans. Raw meat and poultry MUST NOT be washed as this spreads the bacteria.

Norovirus - Shellfish,Raw vegetables, Salads - Nausea, Vomiting, Diarrhoea, Abdominal pain, fever - 1-2 days - Projectile vomiting . The virus can survive for several days if not cleaned up properly.

Question 23

How do you prevent contamination?

Answer 23

**Preventing contamination is the key to food safety.
**
* Keep the kitchen clean and tidy.
* Clean and disinfect all areas ,equipment and utensils used to prepare food.
* Keep food covered.
* Handle the food as little as possible.
* Store food correctly.
* Cook food thoroughly.
* Remove food waste and rubbish.

Question 24

What is food poising?

Answer 24

• Food poisoning is caused by harmful bacteria multiplying in or on food.
• Symptoms usually pass in a few days and the sufferer will make a full recovery.
• Food poisoning can affect anyone, but some people may suffer more than others, such as very young children and babies; elderly people; those who have had a serious illness or are recovering from a serious illness; pregnant women and nursing mothers; people who have allergies.

Question 25

How do you make sure you buy food safely?

Answer 25

• Make sure the food is safe for consumption. Check for signs of damage to tins, packets and packaging.
• Check the date marks - the use-by date and best-before date.
• Stock rotation makes sure that food is used within date (when it is safe) and prevents unnecessary waste.

Question 26

What are use by dates?
What type of food do the go in?
What are the rules about use by dates?

Answer 26

1. A use-by date is a safety date found on foods and their packaging.
2. Use-by dates are found on highly perishable, packaged food such as meat, fish and dairy products that require chilling and have a short shelf life.
3. It is an offence for businesses to sell or use food that has passed its use-by date.

Question 27

What type of food do best before dates go on?

Answer 27

Best-before dates usually appear on less perishable foods that have a long shelf life, such as canned, dried and frozen food products.

Question 27

How should you store food?

Answer 27

• It is important to store food properly.
• Food should be wrapped, covered or kept in a suitable clean container.
• Raw meat, poultry, fish and eggs should always be stored away from ready-to-eat foods.
• Raw vegetables, including salad leaves, may contain pathogens from the soil and should be kept away from ready-to-eat/high-risk foods.
• The refrigerator should be cleaned regularly.
• Dry food ingredients, e.g. dried pasta, tinned tomatoes, herbs and spices should be stored in cupboards that are clean and dry.
• Frozen food still could have bacteria present but they are dormant. Enzymes that cause food spoilage are slowed but not stopped unless inactivated - this is the reason for blanching vegetables before freezing.
• Food ingredients and finished products must be:
• at the correct temperature
  -protected from contamination
• Food ingredients should be used according to the date marks on the food or its packaging.
• Using food within the date marks avoids waste and reduces the risk of cross contamination.

Question 28

What are the conditions needed to put food in the freezer?

Answer 28

• Bacteria are dormant in the freezer.
• Frozen food should be stored at -18 °C or below. Food should be well wrapped to prevent freezer burn through loss of moisture.
• Food bought as frozen should be stored in the freezer as soon as possible.

Question 28

What are the conditions needed to put food in the fridge?

Answer 28

• Fridges should be set to operate at a temperature between 1 °C and 4 °C to make sure that chilled food is held below 5 °C.
• Door handles should be cleaned and disinfected.
• Raw ready-to-eat food and high-risk foods should be kept above raw food (for cooking) in the fridge.
• Food must be kept covered, and food-safe containers and food labels used.
• Never put warm food in a fridge, it will cause the temperature in the fridge to rise into the danger zone (5 °C-63 °C).

Question 29

What conditions are needed to defrost food?

Answer 29

• If frozen foods are not defrosted thoroughly, ice crystals remain at the centre.
• Cooking will melt the ice but the correct core temperature may not be achieved and bacteria may survive.
• Protect defrosting food from being contaminated.
• If high-risk food is defrosted at room temperature, bacteria will start to multiply on the surface of the food.
• Defrosted food must be treated like chilled food.

Question 30

**

What personal hygeine do you have to follow when preparing and cooking food?

Answer 30

• Food handlers are a common source of pathogenic bacteria.
• When preparing food, you must maintain the highest possible standards of personal hygiene in order to avoid contaminating food and causing illness.
• A clean apron should always be worn to protect the food from contamination from your clothes.
• All jewellery should be removed when cooking, food handlers must tie back long hair or wear a hairnet/hat, and fingernails should be kept short and clean with no nail varnish.
• Licking your fingers or utensils when cooking must be avoided.
• Wash your hands:
  -before preparing food
  -between handling raw and high-risk foods or ready-to-eat foods
  -after you have been to the toilet
  -after sneezing/coughing
  -after changing a waterproof plaster
  -after cleaning, after handling food waste or rubbish and known allergens.

Question 31

How to prepare food before cooking?

Answer 31

• Food needs to be protected from contamination during preparation, as the food is usually uncovered while being handled.
• Food should be handled as little as possible. 0 Food must be kept out of the danger zone (5 °C-63 °C) as bacteria will multiply.
• To prevent cross contamination, raw food and cooked food must be prepared separately using separate utensils (different chopping boards and knives).
• Red chopping boards and knives are used for raw meat and should only be used for this purpose

Question 32

What are some high risk foods?

Answer 32

**High-risk foods include:
**
-cold cooked meat poultry
-fish and seafood
-ready meals containing gravy or sauce
-egg products, such as quiche and homemade mayonnaise
-although not high in protein, cooked rice, pasta and cereals are classed as high-risk . as they can provide a -moist environment where certain bacteria can multiply
-dairy-based products, e.g. cream cakes and desserts.

Question 33

What do high risk foods require in terms of preparing?

Answer 33

High-risk foods require strict time and temperature controls.

Question 34

What do you have to be aware of when cooking and reheating food?

Answer 34

• Pathogenic bacteria can be destroyed and food made safe by thorough cooking.
• If food is not cooked correctly, pathogenic bacteria may survive and cause food poisoning. To make sure bacteria are killed, the thickest part of the food (the core) should reach 70 °C for two minutes.
• Liquids should be stirred to avoid cold spots. Large items should be turned to ensure even cooking.
• Poultry, pork and minced meat products must be thoroughly cooked to kill the bacteria.
• If a microwave oven is to be used, always follow the manufacturer’s guidelines.
• Hot holding is the process of storing food warm for service.
• Food must be kept at a temperature of no lower than 63 °C for a maximum of 90 minutes before being discarded.
• Food must not be reheated more than once. Bacteria will multiply during repeated cooling and reheating.
• Reheated food should reach a core temperature of 75 °C.

Question 35

How should you clean properly after to food preparation to avoid cross contamination?

Answer 35

• All food contact surfaces and hand contact surfaces must be cleaned and disinfected after use. Best practice is to ‘clean as you go’.
• Food preparation areas must be kept clean to protect food from: bacterial contamination, physical contamination and chemical contamination.
• Food preparation areas must be kept clean to prevent slips and trips.

Question 36

What are the three types of food poisoning?

Answer 36

1. Microbiological contamination - this is the germ itself contaminating the food.
2. -Physical contamination - this is when items physically drop into food, i.e. rings, nails, hair.
3. -Chemical contamination - this is when chemicals get into food, i.e. cleaning chemicals.

Question 37

What are the steps to safely use a temperature probe?

Answer 37

1. Sterilise before use/use antibacterial spray or wipes
2. Clean after use with anti-bacterial cleanse.
3. Use of antibacterial cleansers will help avoid cross contamination.
4. Switch on. Insert probe into centre/core of food/thickest part of the food
5. Insert at an angle.
6. Do not touch metal baking tin, bone or base with tip of probe.
7. Leave probe in place until temperature stabilises.
8. Temperature must reach 75C or more. It is only temperature which guarantees destruction of harmful bacteria in the food.
9. Follow manufacturer’s instructions for use. Digital probes are run by battery - check battery is active and probe switched on/off as necessary.
10. Do not use battery powered probes in oven or immerse in water.
11. Do not place food probe into another food before cleaning with an anti- bacterial cleanser.
12. If temperature not reached, repeat test.