Transcript food poisoning

Food Safety
Microbial foodborne illness
– Commonly called food poisoning
– Transmitted to human beings through
food and water
– Caused by an infectious agent
(foodborne infection) or a poisonous
substance (food intoxication)
– Episodes far outnumber any other kind
of food contamination
Foodborne illnesses can be life-threatening
Are increasingly unresponsive to standard
antibiotics
Each year in the United States, an
estimated 76 million people become
ill from foodborne diseases
– ≈5,000 of them die
If digestive tract disturbances are
the only major symptom of your next
bout of “stomach flu” chances are
excellent that what you really have is
a foodborne illness
Staphylococcus aureus
– Most common source of food toxicity
– Produced in meats, poultry, egg
products, tuna, potato and macaroni
salads, cream-filled pastries
– Known as “The Buffet” illness
Clostridium botulinum
– Toxin produced under anaerobic
conditions
– Botulism quickly paralyzes muscles
Death can occur within 24 hours
– Botulinum toxin is destroyed by heat
Foods that contain the toxin can be
rendered harmless by boiling them for 10
minutes
Attention on E. coli O157:H7
– In the mid-1990s a fast-food restaurant
chain in the Northwest served
undercooked hamburgers from meat
contaminated with E. coli 0157:H7
4 people died, 100s with serious illness
– 2006 Spinach contamination
3 people died, 192 reported illnesses, 26
states
Infections from E. coli
– Symptoms
Bloody diarrhea
Severe intestinal cramps
Dehydration
In the worst cases, Hemolytic uremic
syndrome leads to abnormal blood clotting
with kidney failure, damage to the central
nervous system and other organs, and
death
Industry Controls--Government
Inspections and HACCP
– The USDA plays a primary role in
inspecting and regulating foods
A USDA inspector monitors U.S. meatprocessing plants every day
– Ensure that they meet government standards
Budget constraints do not allow for such
thorough inspections of seafood, egg,
produce, or processed food facilities
– May receive only one inspection every five years
on average
U.S. producers and handlers of meat,
poultry, seafood, fresh fruit, and
vegetable juices must employ a
Hazard Analysis Critical Control
Point (HACCP) plan
– A systematic plan to identify and correct
potential microbial hazards in the
manufacturing, distribution, and
commercial use of food products
Consumer Protection
– The safety of canned and packaged
foods sold in grocery stores is controlled
through sound food technology practices
– Rare accidents do happen
Batch numbering enables the recall of
contaminated foods through public
announcements
The FDA monitors large food suppliers and
importers
Protect yourself
– Inspect the seals and wrappers of
packages
– Reject open, leaking, or bulging cans,
jars, and packages
– A badly dented can or mangled package
is useless in protecting food
– Frozen foods should be solidly frozen
Myths that often make
consumers sick
– “If it tastes okay, it’s safe to eat.”
– “We have always handled our food this
way, and nothing has ever happened.”
– “I sampled it a couple of hours ago and
didn’t get sick, so it’s safe to eat.”
Food Safety in the Kitchen
Food can provide ideal conditions for
bacteria to thrive or produce toxins
– Disease-causing bacteria require
Warmth
– 40°F - 140°F = 4°C - 60°C
Moisture
Nutrients
To defeat bacteria
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–
–
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Keep
Keep
Keep
Keep
hot food hot
cold food cold
raw foods separate
your hands and the kitchen clean
Food Safety in
the Kitchen
Keep Hot Food Hot
– Cook foods long
enough to reach an
internal temperature
that will kill
microbes
Keep Hot Food Hot
– After cooking, foods must be held at
140°F or higher until served
Cooking does not destroy all bacterial toxins
– Even hot cooked foods, if handled
improperly prior to serving, can cause
illness
– After the meal, cooked foods should be
refrigerated immediately or within two
hours at the maximum
Keep Cold Food Cold: below 40º F
– Start when you leave the grocery store
– Upon arrival home, load foods into the
refrigerator or freezer immediately
– Applies to defrosting foods
Thaw meats or poultry in the refrigerator
Marinate meats in the refrigerator
Any food with an “off” appearance or
odor should not be used or even
tasted
You cannot rely on your senses of
smell and sight alone to warn you
– Most hazards are not detectable by
odor, taste, or appearance
Keep Raw Foods Separate
Prevent cross-contamination of foods
The contamination of foods through exposure to
utensils, hands, or other surfaces that were
previously in contact with contaminated food
Raw foods, especially meats, eggs and
seafood, are likely to contain bacteria
To prevent them from spreading
– Keep the raw foods and their juices away from
ready-to-eat foods
– After handling raw foods wash surfaces,
including your hands, thoroughly with soap
before that surface contacts cooked foods or
foods that are eaten raw
Keep Your Hands and the Kitchen Clean
– Requires
Using freshly washed utensils
Laundered towels
Washing your hands properly
– Remember to use a nailbrush to clean under
fingernails when washing hands and tend to
routine nail care
– Artificial nails, long nails, and chipped polish
harbor more bacteria than do natural, clean, short
nails
Microbes nestle down in small, damp
spaces such as
– The inner cells of sponges
– The pores between the fibers of wooden
cutting boards
Ensure the safety of regular cutting
boards and reduce the microbes in
sponges by washing them in the
dishwasher
Treat kitchen utensils with heat
– Soapy water heated to 140°F kills most
harmful organisms and washes most
others away
– Water must be scalding hot, well beyond
the temperature of the tap
Automatic dishwasher
– Washes in water hotter than hands can
tolerate
– Most dishwasher detergents contain
chlorine
Meats and Poultry
– Require special handling
Packages bear labels to instruct consumers
on meat safety
– Meats in the grocery cooler often
contain all sorts of bacteria
Meats provide a moist, nutritious
environment that is just right for microbial
growth
Ground meat or poultry is handled more
than meats left whole
– Grinding exposes much more surface area for
bacteria to land on
– Experts advise cooking these foods to welldone
Use a thermometer to test the internal
temperature of poultry and meats before
declaring them done
– Burgers often turn brown and appear cooked
before their internal temperature is high
enough to kill harmful bacteria
Eggs
– Raw, unpasteurized eggs are likely to be
contaminated by Salmonella bacteria
FDA requires egg cartons to carry
instruction labels urging consumers:
– keep eggs refrigerated
– cook eggs until yolks are firm
– cook foods containing eggs thoroughly
Raw Produce
– Fruits and vegetables can present a
microbial threat unless they are
thoroughly rinsed in running cold water
to remove microbes before peeling,
chopping, or eating
– Just ten years ago, meats, eggs, and
seafood posed the greatest foodborne
illness threat
Today produce equals them
Raw Produce grown close to the ground
Making bacterial contamination from the soil and
organic fertilizers likely
Much produce is imported from countries
– Farmers may not adhere to sanitary growing
and harvesting procedures
– Contagious diseases may be widespread in the
population
– Fields may be irrigated with unclean water
– Crops may be fertilized with untreated animal
or human manure
– Produce may be picked by infected farm
workers with poor hygiene practices
Rough skins of melons provide
crevices that harbor bacteria
– Should be scrubbed with a brush under
running water before peeling or cutting
All produce should be rinsed
thoroughly under running water for
at least 10 seconds
Unpasteurized or raw juices and
ciders are not safe because microbes
on the original fruit may multiply
Seafood
– A variety of microbial dangers may exist
in even normal-appearing seafood
Viral hepatitis
Worms
Flukes
Other parasites
Viruses that can cause severe intestinal
disorders
Naturally occurring toxins
Dangers posed by seafood have
grown in recent years
– As population density increases along
the seashore, the offshore waters are
becoming more polluted, contaminating
the seafood living there
Viruses that cause human diseases have
been detected in ≈90% of water off the U.S.
coast
– Watchdog agencies monitor commercial
fishing areas to keep harvesters out of
unsafe waters
Unwholesome food can still reach the
market
Honey
– Can contain dormant spores of
Clostridium botulinum that produce the
botulinum toxin
Mature adults are usually protected against
this threat
Infants under one year of age should never
be fed honey
Lunch Bags and Take-Out Foods
– Choose foods that remain safe to eat without
refrigeration
– Carry foods that do well at environmental
temperatures for only an hour or two in a
cooler or thermal lunch bag
– Leftover portions of restaurant meals
Reheat thoroughly (to 140°F) before eating
Discard any portion held at room temperature for
longer than two hours from the time it first appears
on the table until you place it in your refrigerator at
home
Food at Potlucks
Properly prepare food
– Wash, refrigerate, avoid cross-contamination in
preparation, cook to correct temperature
Keep hot foods HOT
– Above 140º F or reheat to 165º F
– Wrap in foil and heavy towels
Keep cold foods COLD
– Below 40º F
– Use a cooler with ice or ice packs
All foods should have serving utensils: spoons, tongs,
spatulas, forks
– Do not handle food with bare hands!
Never leave foods at room temperature for more than 2
hours, transport time and serving time included
Any perishable leftover food should be thrown out!