The Microworld: Factors Affecting Foodborne Pathogens
1
•
Understanding the
Microworld
•
Chapter Number 2
Learning Objectives
After this presentation, you should be able to complete the following
Learning Outcomes
2.0
2
2
.
1
2
.
2
2
.
3
2
.
4
2
.
5
Factors that
a
ffect the growth of foodborne
p
athogens (FAT TOM)
Characteristics of TCS food
Major foodborne pathogens and their sources
Ways of preventing viral, bacteria, parasitic, and fungal
contamination
Naturally occurring
t
oxins and how to
prevent their illnesses
•
Microorganisms:
Small, living
organisms
that can be seen only
with the aid of a
microscope. There
are four types of
microorganisms
that can contaminate food
and
cause foodborne illness: bacteria,
viruses, parasites, and fungi.
•
Pathogens:
Illness-causing
microorganisms.
•
Toxins:
Poisons produced by
pathogens,
plants, or animals. Some
occur in animals
as a result of their
diet.
KEY TERMS
2
.0
•
Bacteria:
Single-celled, living
microorganisms
that can spoil
food and cause foodborne
illness.
Bacteria present in food can quickly
multiply to dangerous levels when
food is
incorrectly cooked, held, or
reheated. Some
form spores that
can survive freezing and very
high
temperatures.
•
FAT TOM:
Acronym for the
conditions needed
by most
foodborne microorganisms to grow:
food, acidity, temperature, time,
oxygen,
moisture.
KEY TERMS
2
.0
•
Temperature danger zone:
The
temperature
range between 41
°
and 135
°
F
(5
°
to 57
°
C),
within which most foodborne
microorganisms rapidly grow.
•
Water activity (a):
Amount of
moisture
available in food for
microorganisms to
grow. It is
measured in a scale from 0.0 to
1.0,
with water having a water activity
(a
w
)
of 1.0. TCS food typically has
a water-
activity value of 0.85 or
higher.
KEY TERMS
2
.0
•
Spore: Form that some
bacteria can take to
protect themselves when
nutrients are not
available. Spores are
commonly found in dirt
and can contaminate food
grown there. A spore can
resist heat, allowing it to
survive cooking
temperatures. Spores can
also revert back to a form
capable of growth. This
can occur when food is not
held at the correct
temperature or cooled or
reheated correctly.
•
Virus: Smallest of the
microbial food
contaminants. Viruses rely
on
a living host to
reproduce. They
usually contaminate food
through
a food handler’s
incorrect personal
hygiene. Some survive
freezing and
cooking
temperatures.
KEY TERMS
2
.0
•
Spore: Form that some
bacteria can take to
protect themselves when
nutrients are not
available. Spores are
commonly found in dirt
and can contaminate food
grown there. A spore can
resist heat, allowing it to
survive cooking
temperatures. Spores can
also revert back to a form
capable of growth. This
can occur when food is not
held at the correct
temperature or cooled or
reheated correctly.
•
Virus: Smallest of the
microbial food
contaminants. Viruses rely
on
a living host to
reproduce. They
usually contaminate food
through
a food handler’s incorrect
personal
hygiene. Some survive
freezing and
cooking temperatures.
KEY TERMS
2
.0
•
Parasite: Organism that
needs to live in a host
organism to survive.
Parasites can be found in
water and inside many
animals, such as cows,
chickens, pigs, and fish.
Correct cooking and freezing
will kill parasites. Avoiding
cross-contamination and
practicing correct
handwashing can also
prevent illness.
•
Fungi: Ranging in size
from
microscopic, single-celled
organisms to very large,
multicellular organisms,
fungi
most often cause food to
spoil.
Molds, yeasts, and
mushrooms are examples.
•
Mold: Type of fungi that
causes food spoilage. Some
molds produce toxins that
can cause foodborne illness.
•
Yeast: Type of fungi that
causes food spoilage.
KEY TERMS
2
.0
2.1
9
Factors That Affect the Growth of Foodborne
Pathogens
F
A
T
T
FOOD
ACIDITY
TIME
TEMPERATURE
OXYGEN
MOISTURE
10
Factors That Affect the Growth of Foodborne
Pathogens
2
.1
Most bacteria need
nutrients such as
carbohydrates
or
proteins
to survive. This
includes meat, poultry,
dairy products, and
eggs.
FOOD
11
Factors That Affect the Growth of Foodborne
Pathogens
2
.1
Bacteria grow
best in food that is
neutral to slightly
acidic, a pH of 7.5 to
4.6
. The following
common types of food
have a pH that is ideal
for bacterial growth:
ACIDITY
Bread – pH 5.0 – 6.0
Raw Chicken – pH 5.5 – 6.0
Milk – pH 6.4 – 6.8
Canteloupe – pH 6.1 – 6.5
12
Factors That Affect the Growth of Foodborne
Pathogens
2
.1
Bacteria
grow rapidly
between 41° and 135°F
(5° and 57°C) This is
called the
Temperature
Danger Zone
.
TEMPERATURE
Bacteria grow even
more rapidly from 70°
to 125°F (21° to 52°C).
13
Factors That Affect the Growth of Foodborne
Pathogens
2
.1
Bacteria need
time
to grow. The more
time
bacteria spend
in the
temperature
danger zone
, the
more opportunity
they have to grow to
unsafe levels.
TIME
Foodborne
Illness
14
Factors That Affect the Growth of Foodborne
Pathogens
2
.1
OXYGEN
Some bacteria need oxygen to grow. Others grow
when oxygen is not there. Bacteria that grow without
oxygen can occur in:
Baked
Potatoes
Cooked Rice
Garlic/Oil
Mixes
15
Factors That Affect the Growth of Foodborne
Pathogens
2
.1
MOISTURE
–
Bacteria grow well in food with high levels of
moisture.
–
The amount of moisture available in food for this
growth is called water activity (a
w
).
–
The a
w
scale ranges from 0.0 to 1.0. The higher the
value, the more available moisture in the food.
16
Characteristics of
TCS Food
2
.2
TCS
(Time and Temperature Control for Safety)
:
TCS food
is typically moist and contains protein, as
well as having a neutral or slightly acidic pH.
17
Characteristics of
TCS Food
2
.2
TCS
(Time and Temperature Control for Safety)
:
This food also has a history of involvement in
foodborne
illness outbreaks, as well as a natural
potential for contamination due to methods used to
produce/process it.
18
Major Foodborne Pathogens
2
.3
•
Microorganisms are small, living organisms that
can be seen only through a microscope.
•
Many microorganisms are harmless, but some
can cause illness. These are called pathogens.
•
Some pathogens make you sick when you eat
them.
•
Others produce poisons—or toxins—that make
you sick.
19
Major Foodborne Pathogens
2
.3
20
Major Foodborne Pathogens
2
.3
•
The symptoms of a foodborne illness vary,
depending on which illness a person has. But
most victims share some common symptoms:
–
Diarrhea
–
Vomiting
–
Fever
–
Nausea
–
Abdominal cramps
–
Jaundice (a yellowing of the skin and eyes)
21
Major Foodborne Pathogens
2
.3
•
The Big Five
–
Shigella
spp
–
Salmonella Typhi
–
Enterohemorrhagic and shiga toxin-producing
E. coli
–
Hepatitis A
–
Norovirus
22
Ways of preventing viral, bacterial, parasitic,
and fungal contamination
2
.4
Prevent
Contamination
Prohibit food
handlers who are
vomiting or who have diarrhea
or jaundice from working
Avoid bare-
hand contact
with
ready-to-eat
food
23
Naturally occurring toxins and ways of
preventing illnesses from them
2
.5
•
Fish toxins can be a natural part of the fish. Other
toxins are made by pathogens on the fish. Some
also occur when fish eat smaller fish containing
the toxin.
•
Shellfish, such as oysters, can likewise become
contaminated when they eat marine algae that
have a toxin.
Seafood Toxins
24
Naturally occurring toxins and ways of
preventing illnesses from them
2
.5
MUSHROOM TOXINS
•
Foodborne illnesses linked with mushrooms
are almost always caused by eating toxic wild
mushrooms collected by amateur hunters.
•
Purchasing products from approved, reputable
suppliers helps prevent these types of
foodborne illnesses.
25
Naturally occurring toxins and ways of
preventing illnesses from them
2
.5
PLANT TOXINS
•
Plant toxins are another form of biological
contamination. Illnesses from plant toxins usually
happen because an operation has purchased plants
from an unapproved source. The following are
examples of items that have made people sick:
–
Toxic plants, such as fool’s parsley or wild turnips,
mistaken for the edible version
–
Honey from bees allowed to harvest nectar from toxic
plants
–
Undercooked kidney beans
This chapter delves into the microworld of microorganisms and pathogens that can contaminate food, leading to foodborne illnesses. It covers key terms such as bacteria, viruses, parasites, and fungi, along with topics on preventing contamination, understanding spores, and the temperature danger zone for microbial growth.
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Presentation Transcript
Chapter Number 2 Understanding the Microworld 1
Learning Objectives After this presentation, you should be able to complete the following Learning Outcomes 2.0 Factors that affect the growth of foodborne pathogens (FAT TOM) 2.1 2.2 Characteristics of TCS food Major foodborne pathogens and their sources 2.3 Ways of preventing viral, bacteria, parasitic, and fungal contamination 2.4 2.5 Naturally occurring toxins and how to prevent their illnesses 2
2.0 KEY TERMS Microorganisms: Small, livingorganisms that can be seen onlywith the aid of a microscope. Thereare four types of microorganismsthat can contaminate food andcause foodborne illness: bacteria, viruses, parasites, and fungi. Pathogens: Illness-causing microorganisms. Toxins: Poisons produced bypathogens, plants, or animals. Someoccur in animals as a result of theirdiet.
2.0 KEY TERMS Bacteria: Single-celled, livingmicroorganisms that can spoilfood and cause foodborne illness.Bacteria present in food can quickly multiply to dangerous levels whenfood is incorrectly cooked, held, orreheated. Some form spores thatcan survive freezing and very hightemperatures. FAT TOM: Acronym for theconditions needed by mostfoodborne microorganisms to grow: food, acidity, temperature, time,oxygen, moisture.
2.0 KEY TERMS Temperature danger zone: The temperature range between 41 and 135 F (5 to 57 C),within which most foodborne microorganisms rapidly grow. Water activity (a): Amount ofmoisture available in food formicroorganisms to grow. It ismeasured in a scale from 0.0 to 1.0,with water having a water activity(aw) of 1.0. TCS food typically hasa water- activity value of 0.85 orhigher.
2.0 KEY TERMS Spore: Form that some bacteria can take to protect themselves when nutrients are not available. Spores are commonly found in dirt and can contaminate food grown there. A spore can resist heat, allowing it to survive cooking temperatures. Spores can also revert back to a form capable of growth. This can occur when food is not held at the correct temperature or cooled or reheated correctly. Virus: Smallest of the microbial food contaminants. Viruses rely ona living host to reproduce. They usually contaminate food througha food handler s incorrect personal hygiene. Some survive freezing andcooking temperatures.
2.0 KEY TERMS Spore: Form that some bacteria can take to protect themselves when nutrients are not available. Spores are commonly found in dirt and can contaminate food grown there. A spore can resist heat, allowing it to survive cooking temperatures. Spores can also revert back to a form capable of growth. This can occur when food is not held at the correct temperature or cooled or reheated correctly. Virus: Smallest of the microbial food contaminants. Viruses rely ona living host to reproduce. They usually contaminate food through a food handler s incorrect personal hygiene. Some survive freezing and cooking temperatures.
2.0 KEY TERMS Parasite: Organism that needs to live in a host organism to survive. Parasites can be found in water and inside many animals, such as cows, chickens, pigs, and fish. Correct cooking and freezing will kill parasites. Avoiding cross-contamination and practicing correct handwashing can also prevent illness. Fungi: Ranging in size from microscopic, single-celled organisms to very large, multicellular organisms, fungi most often cause food to spoil. Molds, yeasts, and mushrooms are examples. Mold: Type of fungi that causes food spoilage. Some molds produce toxins that can cause foodborne illness. Yeast: Type of fungi that causes food spoilage.
Factors That Affect the Growth of Foodborne Pathogens 2.1 FOOD ACIDITY FAT T TIME TEMPERATURE OXYGEN MOISTURE 9
Factors That Affect the Growth of Foodborne Pathogens 2.1 FOOD Most bacteria need nutrients such as carbohydrates or proteins to survive. This includes meat, poultry, dairy products, and eggs. 10
Factors That Affect the Growth of Foodborne Pathogens 2.1 ACIDITY Bacteria grow best in food that is neutral to slightly acidic, a pH of 7.5 to 4.6. The following common types of food have a pH that is ideal for bacterial growth: Bread pH 5.0 6.0 Raw Chicken pH 5.5 6.0 Canteloupe pH 6.1 6.5 Milk pH 6.4 6.8 11
Factors That Affect the Growth of Foodborne Pathogens 2.1 TEMPERATURE Bacteria grow rapidly between 41 and 135 F (5 and 57 C) This is called the Temperature Danger Zone. Bacteria grow even more rapidly from 70 to 125 F (21 to 52 C). 12
Factors That Affect the Growth of Foodborne Pathogens 2.1 TIME Bacteria need time to grow. The more time bacteria spend in the temperature danger zone, the more opportunity they have to grow to unsafe levels. Foodborne Illness 13
Factors That Affect the Growth of Foodborne Pathogens 2.1 OXYGEN Some bacteria need oxygen to grow. Others grow when oxygen is not there. Bacteria that grow without oxygen can occur in: Baked Potatoes Garlic/Oil Mixes Cooked Rice 14
Factors That Affect the Growth of Foodborne Pathogens 2.1 MOISTURE Bacteria grow well in food with high levels of moisture. The amount of moisture available in food for this growth is called water activity (aw). The aw scale ranges from 0.0 to 1.0. The higher the value, the more available moisture in the food. 15
2.2 Characteristics of TCS Food TCS (Time and Temperature Control for Safety): TCS food is typically moist and contains protein, as well as having a neutral or slightly acidic pH. 16
2.2 Characteristics of TCS Food TCS (Time and Temperature Control for Safety): This food also has a history of involvement in foodborne illness outbreaks, as well as a natural potential for contamination due to methods used to produce/process it. 17
2.3 Major Foodborne Pathogens Microorganisms are small, living organisms that can be seen only through a microscope. Many microorganisms are harmless, but some can cause illness. These are called pathogens. Some pathogens make you sick when you eat them. Others produce poisons or toxins that make you sick. 18
2.3 Major Foodborne Pathogens Ways Pathogens can be Spread Person to person Touching dirty food-contact surfaces and then touching food Sneezing or vomiting onto food or food-contact surfaces 19
2.3 Major Foodborne Pathogens The symptoms of a foodborne illness vary, depending on which illness a person has. But most victims share some common symptoms: Diarrhea Vomiting Fever Nausea Abdominal cramps Jaundice (a yellowing of the skin and eyes) 20
2.3 Major Foodborne Pathogens The Big Five Shigella spp Salmonella Typhi Enterohemorrhagic and shiga toxin-producing E. coli Hepatitis A Norovirus 21
Ways of preventing viral, bacterial, parasitic, and fungal contamination 2.4 Prohibit food handlers who are vomiting or who have diarrhea or jaundice from working Prevent Contamination Make sure food handlers wash their hands regularly and correctly Avoid bare- hand contact with ready-to-eat food 22
Naturally occurring toxins and ways of preventing illnesses from them 2.5 Seafood Toxins Fish toxins can be a natural part of the fish. Other toxins are made by pathogens on the fish. Some also occur when fish eat smaller fish containing the toxin. Shellfish, such as oysters, can likewise become contaminated when they eat marine algae that have a toxin. 23
Naturally occurring toxins and ways of preventing illnesses from them 2.5 MUSHROOM TOXINS Foodborne illnesses linked with mushrooms are almost always caused by eating toxic wild mushrooms collected by amateur hunters. Purchasing products from approved, reputable suppliers helps prevent these types of foodborne illnesses. 24
Naturally occurring toxins and ways of preventing illnesses from them 2.5 PLANT TOXINS Plant toxins are another form of biological contamination. Illnesses from plant toxins usually happen because an operation has purchased plants from an unapproved source. The following are examples of items that have made people sick: Toxic plants, such as fool s parsley or wild turnips, mistaken for the edible version Honey from bees allowed to harvest nectar from toxic plants Undercooked kidney beans 25
