Transcript Food Safety and Technology

Food Safety and Technology:
Microbial Threats and Genetic
Engineering
BIOL 103, Chapter 14
Today’s Topic
• Food Safety
• Food Technology
• Genetically Modified Foods
Food Safety
• Harmful substances in foods
– Pathogens (disease-causing)
– Foodborne illness:
1. Infection from pathogen
2. Toxin produced by microorganism
• CDC: “48 million Americans become sick, 128,000
require hospitalization, and 3,000 die from foodborne
illnesses).”
Food Safety
• Harmful substances in food pathogens (Table
14.1: Common Foodborne Pathogens and
Illnesses):
Pathogens
Common Source
Illness
Symptoms
S. aureus
Toxins from S. aureaus
contaminated foods
Vomiting,
abdominal cramps
C. botulinum
Improperly canned foods and
contaminated honey
Fatal to infants
Salmonella
Undercooked and contaminated
poultry/eggs
Diarrhea, Vomiting,
Abdominal cramps
E. coli
Raw or undercooked meat,
vegetables, contaminated water
Watery or bloody
diarrhea, Death
Food Safety
• Prions: self-reproducing protein particles that
can cause a disease such as…
– Mad Cow Disease or Bovine spongiform
encephalopathy (BSE)
Mad Cow Disease
•
Diseased prions induce healthy (prion) proteins to change their
shape (from alpha helix to beta sheets), and clusters of disease build,
leaving holes in the brain.
Mad Cow Disease
• Feeding practices doesn’t help: Recycling dead animals into
livestock feed increase risks spreading of abnormal prions
• Cooking and irradiation do not kill or deactivate abnormal
prions.
Food Safety- Harmful Substances in
Food
• Chemical contamination
– Pesticides
• Important role in food production
• Concerns:
1. ________________________________
2. ________________________________
• FDA collects samples and analyzes food samples
and animal feeds for illegal pesticide residues.
Food Safety – Organic Alternatives
• Organic foods
– “Organic Seals”
– Concerns regarding natural
fertilizer
• Manure can contribute to
contamination of crops,
soil, or water  pollution
– Can use approved
synthetic and natural
pesticides to control weeds
and insects
– Microbial contaminants
still found
Food Safety
• Animal drugs
1. Antibiotics to maintain animal well-being, but
overuse can develop ____________________
microorganisms  illness in humans
2. However, drug residues may enter human food
 _______________ or illness in humans
Food Safety
• Pollutants
– Animal manure, factories wastes/dioxins, human
sewage can contaminate food production areas
– Dioxins: chemical compounds created in the
manufacture, combustion, and chlorine bleaching
of pulp and paper and in other industrial
processes.
• They can accumulate in the food chain and are potent
animal carcinogens.
Food Safety: Harmful Toxins
• Natural Toxins
– Aflatoxins: Carcinogenic and toxic factors
produced by ___________.
– Ciguatera: A toxin found in tropical __________.
• Cooking does not destroy these toxins.
– Methyl mercury: Results from chemical
transformation of mercury by _____________.
– Poisonous mushrooms: cause stomach upset,
hallucinations, neurological symptoms.
– Solanine: Toxic substance in improperly stored
raw _________________________.
Figure 14.5 Toxins in the food chain
As toxins travel up the food chain, they become concentrated in larger
fish.
Figure 14.7 Government agencies that help protect our
food supply
Although the FDA has primary responsibility for the safety of much of our
food supply, many government agencies provide oversight.
Keeping Food Safe: Government
Agencies (Pg587-588)
1. FDA: enforces laws governing safety of
____________________ food, except meat and
poultry.
2. CDC: monitors/investigates outbreaks of ________
_______________and determines proper prevention
3. USDA FSIS: enforces laws governing safety of
domestic and imported ________________ product.
4. USDA CSREES: develops research and education
programs on ______________for farmers/consumers
5. EPA: regulates public ___________, approves
_________________and other chemicals used in the
environment.
Keeping Food Safe: Consumer
• Keep hot foods hot and
cold foods cold
1. Clean
2. Separate
3. Cook
4. Chill (refrigerate
promptly)
Food Safety: Separate, don’t cross-contaminate!
• Separate the re-usable tote bags
• Use different cutting boards for vegetables
and meat.
Risk for Foodborne Illness
1.
2.
3.
4.
5.
6.
7.
Immune disorders
Cancer
Diabetes
Long-term steroid use
Liver disease
Hemochromatosis
Stomach problems
Food Technology
• Food preservation
– Preservatives
1. Salt, sugar
–Most common
antimicrobial agents
2. Antioxidants
– prevents changes in
color/flavor caused by air
exposure
Food Technology
• Other preservation techniques
1.
2.
3.
4.
5.
6.
Salting
Fermenting
Drying
Canning
Heating (e.g. pasteurization)
Irradiation – controversial
Food Technology
• Irradiation – food is exposed to measured
doses of radiation to reduce or eliminate
pathogens and kill insects, reduce spoilage,
and in certain fruits/vegetables, inhibit
sprouting and delay ripening.
• Why are food manufacturers reluctant to use
this method of preservation?
Food Technology: Irradiation
Food Technology
• Bacteriophage: viruses that infect
bacteria
Food Technology
• Bacteriophage
– Sprayed on ready-to-eat meats
and poultry products to
protect people from bacterial
infections
• Infect only bacteria and do not
bother mammalian or plant cells
– Must declare “bacteriophage
preparation”
Genetically Modified Foods
Traditional Breeding
• Cross two plants and
develop hybrids
• Takes time
Genetic Engineering
• Transform specific genes
• Less time needed to get
desired effects
GM foods: Pros and Cons
Benefits
1. Enhanced plant growth
2. _________ pesticide and
fertilizer use
3. Enhanced ___________
composition
4. Enhanced _____________
Risks
• Potential for new ________
• Herbicide-resistant weeds
• Loss of ________________
– Biggest con of unmonitored
GM crops
Food Safety
•
There is no scientific evidence that genetic
engineering and irradiation of foods present
unacceptable risks
Genetically Modified Foods
• Regulation
– _________ oversees genetically modified foods
– Label requirements if food is significantly different
• Examples:
– Changes in ____________ properties
– Presence of ____________ that consumers would not expect
in the food
– Any property that would require special handling, storage,
cooking, or preservations.