Lecture Presentation Outline
I.
Food Safety
 Instructor Resources: Unit 32 Nutrition Scoreboard transparency masters; Unit 32 PowerPoint
presentation on Multimedia Manager; CNN Today Nutrition Vol. 3: Protecting Food (1:56)
A. CDC says annual U.S. foodborne illnesses cause:
1. Sickness in 76 million people
2. 325,000 hospitalizations
3. Over 5,000 deaths
B. Bacteria, viruses, marine life, fungi, toxins they produce, and chemicals in foods or water
1. Spread by many foods, mainly raw or under cooked meat and eggs, shellfish, and raw milk
C. Good Foods Go Bad
 Instructor Resources: transparency #79: Opportunities for the Spread of Foodborne Illness
1.
Bacteria and viruses, most common causes of foodborne illnesses, enter the food supply
during food processing, storage, or preparation
2. Transferred to humans from foods
3. Intestinal bacteria can be harmful to humans
4. These contaminate food by unsanitary practices to prepare and process meats, and when
vegetables and fruits are fertilized with manure
a. Can be transferred to foods by use of human sewage on crops, and food handling by
people carrying the bacteria on their hands
b. Humans transfer microorganisms when fluids from infected injuries or body secretions
contact food
5. Bacteria can be present inside of foods
a. Enter vegetables and fruits if skin coatings are broken
b. Salmonella bacteria in ovaries of hens, who lay normal-looking but infected eggs
c. Shellfish concentrate microorganisms from water
6. “Cross-contamination” increases foodborne illnesses
D. Cross-Contamination
1. Bacteria, viruses, toxins, and other substances contaminate foods during processing,
shipping, preparation, or storage
2. Cross-contamination happens during processing of ground meat, eggs, poultry
3. Cross-contamination from cutting boards
E. Other Substances in Foods
1. Sources of food contamination include:
a. Antibiotics and hormones given to animals
b. Pesticides
c. Industrial pollutants
2. Effects on health vary from life threatening to uncertain
3. Antibiotic Resistance
a. Farm-raised animals given antibiotics to prevent infectious disease
b. Antibiotics may be ones given to humans
c. Microorganisms become resistant to antibiotics
4.
d. Resistant microorganism infections difficult to treat
e. Some foodborne illnesses are from these new forms of bacteria
Hormones
a. Hormones given to farm-raised animals to improve production
b. Hormones appear in foods
c. If products free of additional hormones are safer than those without is unknown
II. Causes and Consequences
 Instructor Resources: Activity 32-2: Laboratory Cultures
A. Foodborne Illness Facts
1. 250 foodborne illnesses from infectious and noninfectious agents have been identified
2. Impact ranges from a day or two of nausea and diarrhea to death within minutes
3. Effects are most severe in people with weakened immune systems or certain chronic
illnesses, pregnant women, young children, and older persons
4. Symptoms of foodborne illness consist of nausea, vomiting, abdominal cramps, and diarrhea
5. Many cases go unreported
a. Estimates based on cases reported by health care professionals and health departments
6. Most prevalent causes result from Salmonella, Campylobacter, and E. coli 0157:H7 bacteria
and Norwalk-like viruses
B. Top Four Causes
1. Salmonella
a. 37,000 cases of Salmonella infection reported to the CDC yearly
b. Actually 1,412,498 cases
c. Estimated that 5% of U.S. experiences Salmonella infection every year
2. Campylobacter
a. Contaminant on chicken causes 2,453,926 bacteria-related foodborne illnesses yearly
b. Bacteria are found on 80% of chickens, 20% are resistant to antibiotics
c. Campylobacter also from unpasteurised milk and contaminated water
3. E. Coli
a. E. coli 0157:H7 evolved into killer
b. 10 bacteria can lead to death in vulnerable people
c. 80,000 cases of E. coli 0157:H7 occur each year, 8% of infected people die
d. E. coli infections are from consumption of undercooked ground beef
e. Recontamination
1. Major outbreak when contaminated leftover ground beef added to next day’s batch
2. Leftover, contaminated meat kept recontaminating subsequent batches
3. Finally, 25 million pounds of ground beef were recalled
4. Norwalk-like Viruses
a. Extremely common, underreported cause of foodborne illnesses
b. Viruses cause acute vomiting that resolves in two days
c. Spread by infected kitchen help and fishermen
d. 23,000,000 cases of Norwalk-like virus related illnesses occur in U.S. each year
C. Related to Seafood
1. Seafood may be contaminated from industrial or human pollution
2. Examples relate to mercury contamination, ciguatera fish poisoning, and neurotoxin
responsible for “red tide”
3.
Mercury Contamination
a. Mercury contamination of waters by fungicides, fossil fuel exhaust, smelting plants, pulp
mills, and chemical plants
b. High levels found in shark, swordfish, and tuna
c. Mercury interferes with fetal brain development, so eating these fish by pregnant women
limited
1. FDA says pregnant women eat no shark, tile fish, swordfish, or king mackerel
d. Consumption of fish by adults in general does not appear to pose a health risk
4. Ciguatera
a. A neurotoxin (ciguatoxin) present in microorganisms called dinoflagellates in reefs
b. Toxin transferred up food chain to humans
c. 200 types may cause ciguatera poisoning, most common:
1. Grouper, red snapper, and barracuda
d. Areas affected include the Caribbean and South Pacific
e. Symptoms 1 to 30 hours after ingestion of poisoned fish are nausea, vomiting, abdominal
cramps, watery diarrhea, numbness, shooting pains in the legs, and other symptoms
f. Toxin not destroyed by cooking, freezing, or digestive enzymes; there is no effective
treatment
5. Red Tide
a. Aquatic microorganism produces nerve toxin
b. Shellfish get contaminated, as are humans who ingest shellfish
c. Resistant to cooking, toxin causes burning sensation in mouth right after consumption
d. Then nausea, vomiting, muscle weakness, loss of feeling in hands and feet
e. Complete recovery typical
D. Botulism
1. Botulism toxin one of the most deadly
2. Causes nerve damage and respiratory failure
3. Clostridium bacteria common in soil, and ocean and lake sediment
4. Contaminate crops, honey, animals, and seafood
5. Botulism usually results from underheated, contaminated foods stored in airtight containers
a. Bacteria thrive in low-oxygen environments and produce gases
b. Foods in airtight containers with bulges should not be eaten
E. Parasites
1. Parasitic worms enter food and water through fecal material and soil
2. Killed by freezing and high temperature
3. Roundworms attach to lining of intestine and feed on your blood
4. 40% of sushi fish contain roundworms, but fish are frozen, so worms are dead
F. Mad Cow Disease
1. A protein called a prion causes deadly disease
a. A prion is a small protein that transmits disease when consumed by a similar species
b. Mad cow disease is transferred to humans who eat prion-infected meat
2. Disease is new form of Creutzfeldt Jakob syndrome, previously identified in humans
3. Inevitably leads to death due to brain damage
4. Illegal to feed cows animal parts that transmit disease
5. Risk of consuming beef from cattle with mad cow disease is small but possibility exists
III. Food Safety Regulations
A. Illegal to produce foods contaminated with substances that cause illness in humans
1. Foods are “safe” if no harm results from repeated exposure to substances in foods
B. Act governs everything added intentionally or accidentally to foods - except pesticides
1. Pesticides are permitted if consumption is associated with “negligible risk”
IV. Irradiation of Foods
A. Food irradiation is a safe process that destroys bacteria, parasites, and viruses in or on foods
B. Availability is limited due to low consumer acceptance of the foods
C. Food irradiation will not prevent all cases
1. Prions, toxins, pesticides, etc. are resistant
2. Irradiated foods can be recontaminated
3. Irradiation does not work well on all foods
V. Food Safety Basics
 Instructor Resources: Activities 32-1: Picnic Selections, 32-3: Food Practices Video, & 32-4: Inept Chef
Role Playing
A. Most food poisoning due to mishandling at home
B. Wash your hands thoroughly with soap and water before and after handling food
1. CDC says this is most important means of preventing spread of foodborne illness caused by
bacteria
C. Keep Foods Hot and Cold
 Instructor Resources: transparency #80: Temperature Guide for Food Safety
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Good foods go bad when stored improperly
Store foods at, and heat them to, the right temperatures
Before serving, hot foods should be kept hot, and cold foods cold
Freezing foods halts growth of contaminating bacteria
When foods are thawed bacteria growth resumes
Danger Range
a. Bacteria grow best between 40° and 140° F
b. Room temperature of homes in this range, so foods should not be left outside the
refrigerator for more than an hour
c. If food was improperly stored it should not be eaten
d. When in doubt, throw it out!
D. Food Handling and Storage
1. Dairy products spoil quickly if contaminated
2. Handle foods with clean hands and utensils, and clean surfaces, reduce bacteria
3. Keep raw meats separate from other foods
4. Utensils and surfaces for meat preparation thoroughly cleaned after use
E. Safety of Canned Foods
1. Commercially canned foods heated until all bacteria killed after can is sealed
2. Contents of cans are sterile, will not spoil if left for years
3. Nevertheless, canned foods may spoil if errors made during the canning process allow
bacteria to survive
4.
5.
Spoiled canned foods build up pressure inside can
a. Pressure causes top of can to bulge out
b. Pressure may be botulism; food must be thrown away
USDA has 24-hour hotline: 1-800-535-4555