Kitchen Hygiene and Food Safety
Food Spoilage
•
Food has a limited life. After a certain time it will go off or
spoil.
•
Food spoilage is caused by: chemicals found in food called
enzymes
; by air; or by micro-organisms, e.g. moulds, yeast
and bacteria (which are also called germs).
•
Food spoilage occurs more quickly when food is:
not stored correctly
prepared in a dirty kitchen
handled by a person who is careless or unhygienic
Enzymes
•
Chemicals that are
naturally present in
fruit and vegetables.
•
They help food to
ripen.
•
After food has been
harvested, enzymes
continue to ripen it,
eventually causing it
to becoming over-
ripe and decay.
Micro-organisms
•
Micro-organisms are tiny living organisms called
germs
.
They include bacteria, yeasts and moulds.
•
They are all around us: in soil, air, water, in humans and
animals.
•
Most micro-organisms are harmless in small amounts, but
in large amounts they can cause food poisoning. Examples
include bacteria, yeasts and moulds.
Micro-organisms: Moulds
In certain conditions,
moulds
form a furry growth on fruit
and bread.
Micro-organisms: Yeasts
Yeasts
cause fruit and jam to go off.
Micro-organisms: Bacteria
Bacteria
cause food poisoning, as well as causing
animal foods like meat and fish to spoil.
Food Spoilage: Oxygen
•
Oxygen
in the air causes fats to go off or become rancid.
This is why unwrapped items like butter develop ‘off’
flavours.
•
Oxygen also reacts with
enzymes, causing discolouration
of foods, e.g. apples go brown.
Food Poisoning
•
Food poisoning
occurs when a person eats or drinks foods
that have large numbers of pathogenic (disease causing)
bacteria. When they enter our body they multiply very
quickly and make us sick.
•
Often foods show no signs of spoilage because there is no
change in colour taste or smell.
Symptoms of Food Poisoning
Symptoms include:
•
Nausea
•
Vomiting
•
Abdominal pains
•
Cramps
•
Diarrhoea
•
High temperature
Food Poisoning Bacteria:
Salmonella
•
Found everywhere, but especially
in the intestines of humans, birds
and animals.
•
Poultry, eggs and raw meat are
sources of salmonella food
poisoning.
•
Pets, rats, mice and insects carry
salmonella and spread it to our
food.
•
It can also be spread as a result of carelessness in personal
hygiene in the bathroom and kitchen, e.g. not washing
hands after going to the toilet.
Food Poisoning Bacteria:
Staphylococci
•
Found mainly in humans –
in the nose, mouth, throat
and in cuts and boils.
•
Passed from humans to
food during food
preparation, e.g. sneezing
or coughing over food, or
through uncovered cuts.
Food Poisoning Bacteria:
Listeria
•
Multiply at a lower temperature
than most bacteria, e.g. in a
fridge so can be in soft cheese,
mayonnaises and pâté.
•
Present in soil on unwashed
fruit, vegetables and salads.
•
Heathy adults are not usually
affected by listeria but they can
cause food poisoning and serious
side effects in babies, older
people and pregnant women.
Food Poisoning Bacteria:
Clostridium Botulinum
•
Botulism
is an extremely
rare but very serious type
of food poisoning.
•
It can result in paralysis
and even death.
•
Clostridium Botulinum
multiplies in faulty cans of
food so always examine
cans before buying – they
must not be rusted, leaking
or bulging.
Food Poisoning Bacteria:
E. coli
•
E. coli
lives in the
intestines of cattle and
sheep and can pass into
the food chain through the
faeces of these animals.
•
E. coli can also
contaminate water
supplies.
Food Poisoning Bacteria:
Campylobacter
•
Found in raw poultry and
meat, unpasteurised milk and
untreated water.
•
Pets with diarrhoea can also
be a source of infection.
•
It is the most common type of
food poisoning in Ireland.
Food Hygiene
•
Bacteria
are tiny invis
i
ble (to the human eye) living cells,
which are found everywhere
:
in the air, water, soil
,
animals
and humans.
•
In small amounts
they
do little harm
–
this is known as an
acceptable level of contamination.
•
However
,
in larger amounts,
they are dangerous
.
In the
right conditions,
they multiply rapidily
,
causing disease and
sometimes death.
Food Hygiene: Conditions for Growth of
Micro-organisms
Warmth
•
Most micro-organisms grow best at 30–40
⁰
C so a warm
kitchen is a suitable place for bacterial growth.
•
Our body temperature is 37
⁰
C so bacteria multiply in the
human body and make us sick.
•
Low temperatures, such as in a fridge (4
⁰
C), slow down the
growth, and very low temperatures like freezing inactivates
them (0
⁰
C or lower) but does not kill them.
•
High temperatures used in cooking kill them.
•
Disinfectants also kill bacteria.
Food Hygiene: Conditions for Growth of
Micro-organisms
(continued)
Moisture
•
All micro-organisms need moisture to grow and multiply. A
lot of moisture is created in a kitchen during cooking and
washing-up. Damp surfaces allow micro-organisms to
thrive.
•
Most foods contains moisture, so bacteria can grow on
these.
•
Bacteria do not grow on dried foods such as flour.
Food Hygiene: Conditions for Growth of
Micro-organisms
(continued)
Food
•
All micro-organisms need food to survive. They feed on
food, dirt and dust, so they grow well in a kitchen.
•
They grow and multiply quickly in protein foods like raw
meat, fish and poultry, and in liquid foods like milk and
custard. A lot of care needs to be taken when storing,
preparing and cooking these foods.
Food Hygiene: Conditions for Growth of
Micro-organisms
(continued)
Oxygen
•
Micro-organisms need air to grow and multiply, so food
should be tightly wrapped to exclude air.
•
Some can survive without air, e.g. in canned or bottled
foods.
Time
•
Micro-organisms multiply quickly, so store food correctly
and use it while it is fresh.
•
A single micro-organism becomes two micro-organisms
every 20 minutes.
Tips to Prevent Food Poisoning
To avoid food contamin
a
tion and
food poisoning
,
food should be
kept:
•
I
n
cool
dry storage areas
,
e.g.
the
fridge
•
C
lean
and
covered
•
I
n a
well
-
ventilated
kitchen to
remove moisture
How Does Food Become Infected
with Bacteria?
1.
Careless and unhygienic food handlers
Not washing hands, especially after using the toilet, not
covering cuts, or coughing and sneezing over food can all
lead to infected food.
2.
Dirt and grease
Dirty preparation areas, equipment, utensils and kitchen
cloths all provide food for bacteria to multiply.
How Does Food Become Infected
with Bacteria?
(continued)
3.
Bacteria
are carried and transferred to food by:
•
Household
pets
, e.g. dogs and cats
•
Insects
like flies and cockroaches
•
Vermin
, e.g. mice and rats
How Does Food Become Infected
with Bacteria?
(continued)
4.
Cross-contamination
This
is the transfer of bacteria from raw to cooked food
from a food handler, or from dirty equipment or surfaces,
e.g. if raw chicken is prepared on the same surface as
salad, bacteria can cross from the raw chicken to the
salad, which can result in food poisoning.
To reduce the risk of cross-contamination, food premises
use coloured-coded equipment, e.g. chopping boards and
knives.
Case Study Activity
Read
Case Study 7.4
and answer the questions that follow.
See Activity 7.4 in the TRB
Think–Pair–Share Activity
Compile a set of guidelines for:
a) Food handlers
b) Preparing food
c) Kitchen hygiene
Kitchen Hygiene and Safety:
Quick Quiz
•
What is meant by food spoilage?
•
What causes food to spoil?
•
Outline the conditions needed for
bacteria to grow.
•
State the causes of food
poisoning.
•
List the symptoms of food
poisoning.
Kitchen hygiene and food safety are crucial to prevent food spoilage and food poisoning. Factors like enzymes, micro-organisms, and oxygen can lead to food spoilage, while food poisoning occurs when pathogenic bacteria multiply in consumed food. Practicing proper hygiene, storage, and preparation methods are essential for maintaining food quality and safety.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
E N D
Presentation Transcript
Chapter 07: Kitchen Hygiene and Safety
Food Spoilage Food has a limited life. After a certain time it will go off or spoil. Food spoilage is caused by: chemicals found in food called enzymes; by air; or by micro-organisms, e.g. moulds, yeast and bacteria (which are also called germs). Food spoilage occurs more quickly when food is: not stored correctly prepared in a dirty kitchen handled by a person who is careless or unhygienic
Enzymes Chemicals that are naturally present in fruit and vegetables. They help food to ripen. After food has been harvested, enzymes continue to ripen it, eventually causing it to becoming over- ripe and decay.
Micro-organisms Micro-organisms are tiny living organisms called germs. They include bacteria, yeasts and moulds. They are all around us: in soil, air, water, in humans and animals. Most micro-organisms are harmless in small amounts, but in large amounts they can cause food poisoning. Examples include bacteria, yeasts and moulds.
Micro-organisms: Moulds In certain conditions, moulds form a furry growth on fruit and bread.
Micro-organisms: Yeasts Yeasts cause fruit and jam to go off.
Micro-organisms: Bacteria Bacteria cause food poisoning, as well as causing animal foods like meat and fish to spoil.
Food Spoilage: Oxygen Oxygen in the air causes fats to go off or become rancid. This is why unwrapped items like butter develop off flavours. Oxygen also reacts with enzymes, causing discolouration of foods, e.g. apples go brown.
Food Poisoning Food poisoning occurs when a person eats or drinks foods that have large numbers of pathogenic (disease causing) bacteria. When they enter our body they multiply very quickly and make us sick. Often foods show no signs of spoilage because there is no change in colour taste or smell.
Symptoms of Food Poisoning Symptoms include: Nausea Vomiting Abdominal pains Cramps Diarrhoea High temperature
Food Poisoning Bacteria: Salmonella Found everywhere, but especially in the intestines of humans, birds and animals. Poultry, eggs and raw meat are sources of salmonella food poisoning. Pets, rats, mice and insects carry salmonella and spread it to our food. It can also be spread as a result of carelessness in personal hygiene in the bathroom and kitchen, e.g. not washing hands after going to the toilet.
Food Poisoning Bacteria: Staphylococci Found mainly in humans in the nose, mouth, throat and in cuts and boils. Passed from humans to food during food preparation, e.g. sneezing or coughing over food, or through uncovered cuts.
Food Poisoning Bacteria: Listeria Multiply at a lower temperature than most bacteria, e.g. in a fridge so can be in soft cheese, mayonnaises and p t . Present in soil on unwashed fruit, vegetables and salads. Heathy adults are not usually affected by listeria but they can cause food poisoning and serious side effects in babies, older people and pregnant women.
Food Poisoning Bacteria: Clostridium Botulinum Botulism is an extremely rare but very serious type of food poisoning. It can result in paralysis and even death. Clostridium Botulinum multiplies in faulty cans of food so always examine cans before buying they must not be rusted, leaking or bulging.
Food Poisoning Bacteria: E. coli E. coli lives in the intestines of cattle and sheep and can pass into the food chain through the faeces of these animals. E. coli can also contaminate water supplies.
Food Poisoning Bacteria: Campylobacter Found in raw poultry and meat, unpasteurised milk and untreated water. Pets with diarrhoea can also be a source of infection. It is the most common type of food poisoning in Ireland.
Food Hygiene Bacteria are tiny invisible (to the human eye) living cells, which are found everywhere: in the air, water, soil, animals and humans. In small amounts they do little harm this is known as an acceptable level of contamination. However, in larger amounts, they are dangerous. In the right conditions, they multiply rapidily, causing disease and sometimes death.
Food Hygiene: Conditions for Growth of Micro-organisms Warmth Most micro-organisms grow best at 30 40 C so a warm kitchen is a suitable place for bacterial growth. Our body temperature is 37 C so bacteria multiply in the human body and make us sick. Low temperatures, such as in a fridge (4 C), slow down the growth, and very low temperatures like freezing inactivates them (0 C or lower) but does not kill them. High temperatures used in cooking kill them. Disinfectants also kill bacteria.
Food Hygiene: Conditions for Growth of Micro-organisms (continued) Moisture All micro-organisms need moisture to grow and multiply. A lot of moisture is created in a kitchen during cooking and washing-up. Damp surfaces allow micro-organisms to thrive. Most foods contains moisture, so bacteria can grow on these. Bacteria do not grow on dried foods such as flour.
Food Hygiene: Conditions for Growth of Micro-organisms (continued) Food All micro-organisms need food to survive. They feed on food, dirt and dust, so they grow well in a kitchen. They grow and multiply quickly in protein foods like raw meat, fish and poultry, and in liquid foods like milk and custard. A lot of care needs to be taken when storing, preparing and cooking these foods.
Food Hygiene: Conditions for Growth of Micro-organisms (continued) Oxygen Micro-organisms need air to grow and multiply, so food should be tightly wrapped to exclude air. Some can survive without air, e.g. in canned or bottled foods. Time Micro-organisms multiply quickly, so store food correctly and use it while it is fresh. A single micro-organism becomes two micro-organisms every 20 minutes.
Tips to Prevent Food Poisoning To avoid food contamination and food poisoning, food should be kept: In cool dry storage areas, e.g. the fridge Clean and covered In a well-ventilated kitchen to remove moisture
How Does Food Become Infected with Bacteria? 1. Careless and unhygienic food handlers Not washing hands, especially after using the toilet, not covering cuts, or coughing and sneezing over food can all lead to infected food. 2. Dirt and grease Dirty preparation areas, equipment, utensils and kitchen cloths all provide food for bacteria to multiply.
How Does Food Become Infected with Bacteria? (continued) 3. Bacteria are carried and transferred to food by: Household pets, e.g. dogs and cats Insects like flies and cockroaches Vermin, e.g. mice and rats
How Does Food Become Infected with Bacteria? (continued) 4. Cross-contamination Thisis the transfer of bacteria from raw to cooked food from a food handler, or from dirty equipment or surfaces, e.g. if raw chicken is prepared on the same surface as salad, bacteria can cross from the raw chicken to the salad, which can result in food poisoning. To reduce the risk of cross-contamination, food premises use coloured-coded equipment, e.g. chopping boards and knives.
Case Study Activity Read Case Study 7.4 and answer the questions that follow. Think Pair Share Activity Compile a set of guidelines for: a) Food handlers b) Preparing food c) Kitchen hygiene See Activity 7.4 in the TRB
Kitchen Hygiene and Safety: Quick Quiz What is meant by food spoilage? What causes food to spoil? Outline the conditions needed for bacteria to grow. State the causes of food poisoning. List the symptoms of food poisoning.
