sansatation and spoilage

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Transcript sansatation and spoilage


Ask the students when was the last time they washed their hands.
Tell them to look at their hands and notice the natural lines, cracks,
and wrinkles. These are the perfect places for dirt and germs to
hang out. Give each student a magnifying glass. Have the students
use the magnifying glasses to examine their hands more closely.
Ask them what they see. They should be able to better see the
natural cracks, lines, and wrinkles of their hands, and they may
also be able to see some dirt on their hands. Tell them that no
matter how hard they look, they will not see any germs. Germs are
microorganisms that can only be seen with a microscope. Just
because they can’t see them, however, does not mean that they
aren’t there. Inform the students that germs live everywhere and
billions of them grow and live on their bodies every day. Most of
these germs are not harmful, but the germs we pick up from
everything around us can be harmful. Many of them can make us
sick. If these harmful germs get onto our food, they can spread and
cause food poisoning. We must wash our hands frequently and do
whatever else we can to prevent spreading harmful germs that can
make us sick.
1
Discuss food safety.
2
Outline safe food handling.
3
Name methods of food preservation.
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Aseptic packaging
Blanching
Canning
Contamination
Curing
Dehydration
Fermentation
Food-borne illness
Food preservation
Food spoilage
Freezing
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Irradiation
Paraffin
Pasteurization
Pathogen
Perishable food
Pickling
Refrigeration
Sterilization
Vacuum wrapping
Wholesome food
 Anticipated
Problem: How do we
guarantee safe food?
 I. Food
is an essential component in our
lives. Food provides the nutrients
required for us to live. Steps must be
taken to keep our food safe for us to eat.
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A. Food safety is very
important to insure that the
foods we eat are wholesome.
Wholesome food is food that
is nutritious and safe to eat.
Wholesome food does not
contain foreign substances
that could make us sick.
Spoiled food or food with
foreign substances in it is
unwholesome. Unwholesome
food may cause sickness.
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B. A food-borne illness is an illness that results from
eating unwholesome food.
1. Symptoms of food-borne illness include fever, vomiting,
diarrhea, abdominal cramps, and headache.
2. About 76 million people become ill each year from the
food they eat. Of those, 325,000 need to be hospitalized.
3. About 5,000 people die each year from food-borne
illness.
4. It is estimated that proper hand washing could
eliminate over half of the cases of food borne illness.
5. At least 85% of food-borne illnesses can be avoided by
handling food properly.
6. Bacteria such as Salmonella, E. coli, and Clostridium
botulism are common causes of food-borne illness.
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C. Food spoilage is a condition in which food
becomes unsafe to eat. The food may be decaying.
Most food spoilage is caused by bacteria and fungi.
Food that is spoiled is not safe to eat.
D. Food must be handled safely to avoid
contamination. Contamination is the addition of
something unwholesome or undesirable.
Contaminated food is not safe to eat.
E. To keep food safe, it must be properly handled
throughout the food chain, from the farm to the
consumer.
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F. Some foods must be packaged
and stored differently to prevent
spoilage because they do not keep
as well as others. Perishable food
is food that is highly susceptible to
spoilage and must be consumed in
a short period of time. All types of
food will eventually spoil if they
are not preserved, but some foods
are more perishable than others.
Bread, meat, and dairy products,
for example, are more perishable
than grains and nuts.
 G. Temperature
is very important
in preventing illness from
pathogens. A pathogen is a
contaminant that causes sickness.
Bacteria, molds, and fungi are
common pathogens. Most
pathogens can only live in
temperatures between 40°F and
140°F. Pathogens cannot be seen
or smelled. When a product looks
or smells bad, then it is already
too late.
 H. Government
regulations help insure
that our food is safe. The United States
Department of Agriculture (USDA) is
responsible for inspecting food. The
Federal Food and Drug Administration
(FDA) monitors the food supply to make
sure that all laws are being followed.
 Anticipated
Problem: How do you handle
food properly?
 II. Handling
food properly keeps our food
safe and helps reduce the risk of foodborne illness. The Four Cs of Food Safety
can be used as guidelines for handling
food safely—clean, cook, combat crosscontamination, and chill.
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A. Clean—
1. Wash your hands, all utensils, and
surfaces in warm soapy water before
and after preparing food, especially
after handling raw meat, poultry,
eggs, or seafood.
 2. Rinse raw produce under running
water. Cut off any bruised or
damaged areas.
 3. Use paper towels for cleaning up
kitchen surfaces, and throw them
away when done. If cloth towels are
used, wash them often in the hot
cycle of your washing machine.
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B. Cook—
1. Cook food to the proper
temperature. You cannot tell if
food is properly cooked just by
looking at the color.
 2. Use a clean meat
thermometer to check the
temperature of meat. All meat
should be cooked to the proper
temperature. Seafood should be
cooked until opaque. Cook
eggs until they are firm and no
liquid remains.
 3. All leftovers should be
reheated to 165°F.
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C. Combat Cross-Contamination—
1. Raw meat, poultry, and seafood should be sealed and kept
separate from other foods in your refrigerator to avoid
contamination.
2. Either clean cutting boards thoroughly between uses or use
different cutting boards for meats and fresh produce.
3. Wash your hands, cutting boards, dishes, and utensils after use.
4. Do not place cooked food on the same dish where raw food was
held.
5. Do not use sauces that were used for marinating raw meat unless
you boil them first.
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D. Chill—
1. Refrigerate food at 40°F or
lower.
2. Refrigerate leftover food as
soon as possible but always within
two hours.
3. Put leftovers in shallow
containers for quick cooling.
4. Marinate and thaw foods in the
refrigerator, not on the counter or
in the sink at room temperature.
5. Do not pack the refrigerator too
full because it does not allow cold
air to circulate.
6. Pack coolers full and with
plenty of ice to keep foods cool at
picnics or barbeques.
 Anticipated
Problem: What are some
methods of food preservation?
 III. Food
preservation is the treatment of
food to keep it from spoiling. Food
preservation can be accomplished by
several methods.
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A. Canning is a method of food
preservation in which food is
placed in a container and
heated at high temperatures
under pressure to kill all
microorganisms. The food
containers are held at the right
temperature for a period of time
and then cooled. An airtight seal
must be created on the
container to keep
microorganisms from getting
back into the container after it
cools. Vegetables, fruits, and
meats can be canned.
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B. Freezing is a preservation method in
which foods are stored at a low temperature
so the water in the product becomes ice.
Most microbial activity stops when frozen.
Fruits, vegetables, and meat can all be
frozen. Foods should be prepared carefully
for freezing.
1. Only food free of decay should be frozen.
2. Most fruits and vegetables are blanched
before freezing. Blanching is a heat
treatment designed to raise the temperature
of food between 180°F to 190°F followed by
rapid cooling. Blanching does not destroy
microorganisms. It inactivates enzymes that
can alter the taste and color of a food
product.
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C. Fermentation is a method of food
preservation that uses the carefully
controlled activity of certain bacteria,
molds, and yeasts. Fermentation is used in
making wines, breads, vinegars, and
cheeses.
D. Dehydration, or drying, is a method of
preservation that involves the removal of
all the moisture from a food product.
Microbes require moisture to function, so
removing the water ends their activity.
Fruits and meats are often dehydrated.
Raisins and beef jerky are examples of
dried foods.
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E. Curing is a food preservation method in
which substances that prevent
microorganism growth are added to foods to
prevent spoilage. Concentrations of salt,
sugar, sodium nitrate, and other materials are
used for curing. Meats are often cured.
F. Refrigeration is a method of food
preservation that involves storing foods
between freezing and room temperature.
Refrigeration does not kill any
microorganisms, but it slows down their
growth. Many foods are refrigerated
temporarily.
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G. Pasteurization is a heat treatment
that kills all pathogenic microorganisms
(ones that cause illness) but does not
kill all spoilage microorganisms. All
milk in stores has been pasteurized.
H. Irradiation is a food preservation
method in which foods are treated with
electrically charged particles, such as
X-rays, electron beams, or gamma rays.
Low amounts of radiation will kill
spoilage organisms. Meats and fruits
are often irradiated.
 I. Special
packaging can be used to
preserve food.
 2. Vacuum
wrapping is a method of food
preservation in which all oxygen is
removed from the food’s packaging.
Microorganisms cannot grow without
oxygen. Vacuum wrapped foods can be
stored for quite some time at the proper
temperature without spoiling.
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J. Pickling is a food preservation method that
prevents the growth of spoilage organisms by
placing foods in acid solutions. Vinegar is
commonly used for pickling. Cucumbers,
cauliflower, okra, peppers, other vegetables,
and some meat products are pickled.
K. A thin layer of paraffin, a type of wax, can
be applied to some foods to preserve them.
The paraffin holds moisture in and keeps
organisms out. Apples and rutabagas are
commonly coated with a thin layer of
paraffin.
1. How
do we guarantee safe food?
2. How
do you handle food properly?
3. What
are some methods of food
preservation?