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Judith E. Brown
www.cengage.com/nutrition/brown
The Multiple Dimensions
of Food Safety
Unit 32
Prof. Albia Dugger • Miami-Dade College
Threats to Food Safety
• Each year, US foodborne illnesses cause:
• Sickness in 76 million people
• 325,000 hospitalizations
• Over 5,000 deaths
Key Terms
• Foodborne illness
• Illness related to consumption of foods or
beverages containing disease-causing bacteria,
viruses, marine organisms, fungi, toxins,
parasites, or other contaminants
How Good Foods Go Bad
• The most common contaminants (bacteria
and viruses) enter the food supply during food
processing, storage, or preparation
• Contamination through feces is common
• From intestines in meat processing
• From animal manure used on vegetable crops
• From handling by people with dirty hands
Potential for Spreading
Foodborne Illness
Contaminants In Foods
• Foods can be contaminated from the inside
• Eggs of chickens infected with Salmonella
• Shellfish that filter contaminants from water
• Bacteria that enter fruits and vegetables with
broken skins
Cross-Contamination
• Cross-contamination occurs when food that is
contaminated comes into contact with another
food
• At food processing plants
• During preparation at home
Other Substances in Foods
• Foods can be contaminated with other
substances that have been intentionally or
unintentionally added
• Antibiotics
• Hormones
• Pesticides and PCBs
Antibiotic Resistance
• Farm-raised animals are commonly given
antibiotics in feed
• Microorganisms become resistant to the
antibiotics and infect people – and infections
caused by antibiotic-resistant organisms are
difficult to treat
Hormones
• Farm-raised animals are commonly given
hormones to promote growth or improve milk
production
• The safety of consuming meat and milk
products containing these hormones is under
investigation
Pesticides and PCBs
• Pesticides containing organophosphates,
mercury-containing fungicides, and DDT can
cause foodborne illnesses
• PCBs from contaminated land and water have
been linked to cancer
Pesticides and PCBs
• <1 in 10,000 foods
contain excessive
pesticide levels
• Farm workers are at
greatest risk
Causes of Foodborne Illness
• Over 250 types of foodborne illnesses caused
by infectious and noninfectious agents have
been identified
• Effects range from nausea and diarrhea to
death within minutes
High-Risk Groups
Top 4 Causes
Salmonella
• CDC estimates >1.4
million cases of
Salmonella infection
occur each year
• 5% of US population
experience a
Salmonella infection
each year
Other Causes: Seafood
• Illnesses caused by
seafood contaminated
by water pollution
• Mercury poisoning
• Ciguatera poisoning
• “Red tide” poisoning
Seafood
• Mercury contamination
• In large fish from mercury-contaminated waters
• Ciguatera (neurotoxin)
• In fish from reefs with toxic dinoflagellates
• “Red tide” (neurotoxin)
• In shellfish that eat toxic microorganisms
Ciguatera Poisoning
• Tropical reef fish eat
toxic dinoflagellates
• Poison cannot be
destroyed, and there is
no effective treatment
Other Causes: Botulism
• C. botulinum bacteria
produce deadly toxin in
airtight containers
• Foods in bulging
containers should not
be eaten
Other Causes: Parasites
• Parasitic tapeworms, flatworms, and
roundworms enter food and water through
fecal material and soil
• Most are killed by cooking or freezing
Other Causes: Mad Cow Disease
• Bovine spongiform encephalopathy (BSE)
• Deadly disease caused by an infectious protein
(prion) – not destroyed by cooking
• Started when cows were fed sheep body parts
• Transmitted to humans who ate infected cows
• Human disease may take 20 years to develop
Preventing Foodborne Illness
• There are two major approaches to
prevention of foodborne illness:
• Regulations that control food processing and
handling practices
• Consumer behaviors that reduce risk of
consuming contaminated food
Food Safety Regulations
• The Federal Food, Drug, and Cosmetic Act
regulates all substances added intentionally
or accidentally to foods – except pesticides
• Pesticides with a “negligible risk” of health
problem are permitted in foods
Irradiation of Foods
• Irradiation destroys bacteria, parasites, and
viruses in foods
• Irradiation does not destroy prions, toxins,
pesticides, mercury or PCBs – or prevent later
contamination
The Consumer’s Role
• Food Safety Basics:
• Scrub your hands thoroughly with soap and water
for at least 20 seconds
• Cook foods thoroughly; keep hot foods above
140°F, and cold foods below 40°F
• Don’t consume raw milk, meat, or eggs
• Follow USDA safe handling instructions
• Throw away canned foods that bulge out
Safe Cooking Temperatures
Safe Handling Temperatures
Safe Storage
USDA Safe Handling Instructions
Take Action:
• Until contamination of food is prevented,
consumers must take responsibility for
reducing risks of foodborne illnesses
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Buy locally grown produce
Plant a vegetable garden
Buy irradiated raw meats
Buy only pasteurized dairy products