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Food Safety and Contamination
Year 8 Food Technology Term One
Safe Food
Food hygiene and safety is about ensuring that the food that
we consume is safe to eat and does not put us at risk of food
poisoning.
Food safety regulations in Australia help to ensure that food is
safe up until the time that it reaches us in the kitchen- whether
that is at school or home.
Once the food is with us in the kitchen it is up to
us to make sure that it is stored and prepared
in a safe way.
Cross Contamination
Cross Contamination occurs when bacteria and viruses are
transferred from a contaminated surface to a surface that is not
contaminated.
These bacteria and viruses can be transferred from humans,
kitchen equipment, work surfaces and other foods
Everyone who handles food from the farmer to the butcher and
the chef, must ensure that they follow good hygiene practices to
avoid cross contamination
Types of Food Contamination
Bacteria is not the only cause of food poisoning. If we eat
food that has been contaminated we can become sick. Food
Can be contaminated by the following:
Chemicals
Foreign Matter
Organisms
Natural Toxins
Types of Food Contamination:
Chemicals
Chemical substances such as food additives and cleaning
products are safely used in the production of food. They
assist farming, help preserve food and make it look and taste
better. They can be used safely for cleaning and pest control.
Chemicals in the home include those used:
• To clean kitchen surfaces and equipment
• As pesticides
Types of Food Contamination:
Chemicals
When chemicals are used inappropriately or incorrectly, food
can become unsafe. Chemicals can become very harmful if
they are:
• Spilt on or near food
• Mistaken for food or drink
The following actions will help to prevent contamination of
food with chemicals
• Always read the safety directions
• Chemicals should not be stored near food
• Chemicals should never be put in food containers or drink
bottles and should always be labelled clearly.
Types of Food Contamination:
Natural Toxins
Toxins are poisonous substances produced by some microorganisms, plants and animals. Most toxins that can make us sick
are tasteless and will not breakdown when we cook our food.
Potatoes, nuts, mushrooms, and seafood can all contain natural
toxins under certain conditions.
For example:
• When potatoes are exposed to light and turn green they produce
toxins.
• Fish and other seafood can build up toxins if they feed on algae
or other fish that contain toxins
Types of Food Contamination:
Foreign Matter
Sometimes foreign matter such as hair, jewellery, glass, dead
insects and pieces of metal finds its way into food. Foreign
matter such as glass and metal can physically injure
someone. Risks include broken teeth, cuts to the throat and
piercing of the gut.
Other foreign matter can introduce harmful micro-organisms
into food, which can then result in food poisoning.
Food Contamination: Organisms
Organisms are a more common cause of food poisoning than
chemicals, natural toxins and foreign matter. This is mostly due to
micro-organisms (germs), though there are larger, visible organisms
of concern such as some moulds or parasites.
There are many different types of microorganisms. Most of them are so small that
millions could sit on the head of a pin. Most of
them are harmless to humans. Some are used
to make foods such as yoghurt and bread.
However others can make us very sick
The organisms that can make us sick include:
Viruses, Mould, Parasites and Bacteria
Food Contamination: Organisms
• Viruses
Viruses are extremely small micro-organisms that need a living body in
which they grow and multiply. They do not grow in food.
• Viruses that cause food poisoning usually live in humans. When
someone has a viral illness, they can pass the illness onto others by
contaminating food with the virus.
Only a small number of viruses need to be taken into the body for a
person to become sick.
• This is why good personal hygiene is important when handling food. It
is also one of the reasons we shouldn’t handle food when we are sick.
Food Contamination: Organisms
• Parasites:
Parasites feed off other organisms. If we eat food that is
contaminated with parasites, we can become sick. Parasites
can be found in the flesh of many animals. To safeguard us
Australia has strict controls over all meat for sale. Thorough
cooking kills parasites.
Food Contamination: Organisms
• Mould
Moulds are a type of fungus. Usually moulds can be seen and
there are both good and bad moulds. Some good moulds are
used to manufacture food, such as certain soft cheeses.
However other moulds can make food look unattractive and
spoil it. Some moulds even produce poisonous toxins. We
should not eat mould, except when it is used intentionally.
Food Contamination: Organisms
• Bacteria
Bacteria are one of the main causes of food poisoning. They
are also an essential part of the living environment. Most
bacteria on food just make the food deteriorate. However some
bacteria on food or those living in or on us can make us sick.
Under the right conditions, bacteria can multiply to large
numbers in our food to the point that our body cannot fight them
off. Two common examples of food poisoning that can make us
sick are Campylobacter and Salmonella.
Campylobacter
Salmonella
The Danger Zone
The Danger Zone is the temperature at which bacteria multiply rapidly.
Foods that could give us food poisoning should be kept below 4℃ if
they are be served cold or above 60℃if they are served hot
The temperature danger zone is between 4℃ and 60 ℃; it is between
this temperature range that bacteria can grow to unsafe levels
Low temperatures (below 4℃ ) prevent
food poisoning bacteria from multiplying to
dangerous levels and high temperatures
(above 60 ℃ ) will kill bacteria and viruses