Transcript Nutrition Now J. Brown

Chapter 12
Food Safety and
the Global Food
Supply
© 2007 Thomson - Wadsworth
Ask Yourself
1.
2.
3.
4.
5.
Pesticides rank as the number one hazard in
the U.S. food supply.
The most frequent cause of foodborne illness
in homes and restaurants is inadequate
cooling of foods.
If a food contains a toxic substance, a
person who eats it will become ill.
Tainted mayonnaise frequently causes food
poisoning.
Imported foods may contain residues of
pesticides that are illegal in the United
States.
© 2007 Thomson - Wadsworth
Ask Yourself
6.
A USDA rule on organic crops allows the use
of genetically-engineered ingredients and
irradiation in organic foods.
7. Hunger in the United States afflicts almost
exclusively underemployed homeless people.
8. Legal pesticides are poisonous only to pests,
not to people.
9. Most foods that cause food poisoning are
contaminated by the manufacturer or
processor.
10. Food additives are a major cause of cancer
in the United States.
© 2007 Thomson - Wadsworth
Foodborne Illnesses and the
Agents that Cause Them
• Foodborne illness: illness
occurring as a result of ingesting
food or water contaminated with
a poisonous substance, such as:
 A toxin or chemical (food
intoxication)
…or an infectious agent such as:
 Bacteria
 Viruses
 Parasites (foodborne
infection)
• Commonly called food
poisoning.
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Foodborne Illnesses and the
Agents that Cause Them
• Pasteurization: the process of sterilizing food via
heat treatment.
• Food intoxication: illness caused by eating food
that contains a harmful toxin or chemical.
• Enterotoxin: a toxic compound, produced by microorganisms, that harms mucous membranes, as in the
gastrointestinal tract.
 entero = intestine
• Neurotoxin: a poisonous compound that disrupts
the nervous system.
 neuro = nerve
• Foodborne infection: illness caused by eating a
food containing bacteria or other microorganisms
capable of growing and thriving in a person’s tissues.
© 2007 Thomson - Wadsworth
Foodborne Illnesses and the
Agents that Cause Them
© 2007 Thomson - Wadsworth
Foodborne Illnesses and the
Agents that Cause Them
• Handle raw meat and poultry with care and cook it
thoroughly to destroy any bacteria present.
• Place it on a clean plate when it is cooked.
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© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
Foodborne Illnesses and the
Agents that Cause Them
• Aflatoxin: a
poisonous toxin
produced by
molds.
• Toxicants:
poisons, that is,
agents that cause
physical harm or
death when
present in large
amounts.
© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
Safe Food Storage and
Preparation
1.
Keep Cold Foods Cold
•
•
Store foods in a refrigerator set at 40 degrees;
freezer at 0 degrees.
Thaw frozen food on a plate in the refrigerator; or
microwave as part of the cooking process.
2. Wash Hands and Surfaces Often
•
•
•
Wash hands in warm, soapy water before
beginning food preparation.
Wash hands again after handing meat, poultry or
fish.
Keep countertops, and kitchen equipment clean
with hot, soapy water.
© 2007 Thomson - Wadsworth
Safe Food Storage and
Preparation
3. Keep Hot Foods Hot
•
•
•
•
Cook foods thoroughly to destroy any bacteria that is
present.
Keep foods hot until serving.
Never leave food at room temperature for more than 2
hours.
Refrigerate leftovers.
4. Prevent cross-contamination: the inadvertent
transfer of bacteria from one food to another that occurs,
for instance, by chopping vegetables on the same cutting
board used to skin poultry.
© 2007 Thomson - Wadsworth
Safe Food Storage and
Preparation
5. Food Safety for Meats
•
•
Ground meat is especially susceptible to bacterial
contamination.
Cook to a well done stage and use a meat
thermometer.
6. Food Safety for Seafood
•
•
Seafood should be handled with care, especially
fish intended to be eaten raw.
Because of risk of contamination, the hazards of
eating raw or undercooked seafood need to be
weighed carefully, especially by vulnerable people,
including those with liver disease, gastrointestinal
disorders, HIV infection and other diseases that
compromise the immune system.
© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
Safe Food Storage and
Preparation
• Mad cow disease (bovine
spongiform encephalopathy or
BSE): a rare and fatal degenerative
disease first diagnosed in 1986 in cattle
in the United Kingdom.
The bovine disease may be passed to
humans who eat the meat of infected
animals and may lead to death due to
brain and nerve damage.
© 2007 Thomson - Wadsworth
Safe Food Storage and
Preparation
© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
Pesticides and Other
Chemical Contaminants
• Contaminants:
potentially
dangerous
substances, such as
lead, that can
accidentally get
into foods.
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Pesticides and Other
Chemical Contaminants
• Organic halogens: compounds that contain
one or more of a class of atoms called
halogens, including fluorine, chlorine, iodine,
or bromine.
• Heavy metals: any of a number of mineral
ions, such as mercury and lead, so named
because of their relatively high atomic weight.
 Many heavy metals are poisonous.
• Toxicity: the ability of a substance to harm
living organisms.
 All substances are toxic if present in high enough
concentrations.
• Hazard: state of danger; used to refer to any
circumstance in which harm is possible.
© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
Pesticides and Other
Chemical Contaminants
© 2007 Thomson - Wadsworth
Pesticides and Other
Chemical Contaminants
• Pesticides: chemicals applied intentionally to
plants, including foods, to prevent or eliminate
pest damage.
 Pests include all living organisms that
destroy or spoil foods:
• Bacteria
• Molds
• Fungi
• Insects
• Rats and other rodents
… to name a few.
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Pesticides and Other
Chemical Contaminants
• Regulation: a legal
mandate that must be
obeyed.
 Failure to follow a
regulation brings
about serious legal
consequences.
• Foods imported from
other countries may
harbor residues of
pesticides that have been
banned for use in the
United States.
© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
Pesticides and Other
Chemical Contaminants
• Risk: the harm a substance may confer.
 Scientists estimate risk by assessing the amount of a
chemical that each person in a population might
consume over time (also called exposure) and by
considering how toxic the substance might be
(toxicity).
• risk = exposure x toxicity
• exposure = amount of substance in food x
amount of food eaten
• Tolerance: the maximum amount of a particular
substance allowed on food.
• Reference dose: the estimated amount of a chemical
that could be consumed daily without causing harmful
effects.
© 2007 Thomson - Wadsworth
Margin of safety: from a food safety standpoint, the
margin is a zone between the maximum amount of a
substance that appears to be safe and the amount
allowed in the food supply.
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© 2007 Thomson - Wadsworth
Pesticides and Other
Chemical Contaminants
© 2007 Thomson - Wadsworth
Food Additives
• Food additive: any substance added to food, including
substances used in the production, processing,
treatment, packaging, transportation, or storage of
food.
• Intentional food additives: substances intentionally
added to food. Examples include:
 Nutrients
 Colors
 Spices
 Herbs
• Incidental food additives (or indirect additives):
substances that accidentally get into food as a result of
contact with it during growing, processing, packaging,
storing, or some other stage before the food is
consumed.
© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
Food Additives
• GRAS (Generally
Recognized As Safe): a
list of ingredients,
established by the FDA,
that had long been in use
and were believed
safe.The list is subject to
revision as new facts
become known.
• Delaney clause: a
provision in the 1958
Food Additives
Amendment that
prohibited manufacturers
from using any
substance that was
known to cause cancer in
animals or humans at
any dose level.
© 2007 Thomson - Wadsworth
Should You Buy Organically
Grown Produce or Meats?
• Organically grown foods:
crops or livestock grown and
processed according to USDA
regulations concerning use of
pesticides, herbicides,
fungicides, fertilizers,
preservatives, other synthetic
chemicals, growth hormones,
antibiotics, or other drugs.
• Integrated pest
management: the use of
biological controls, crop
rotation, genetic engineering,
and other tactics to reduce
chemical use in the growing of
crops.
© 2007 Thomson - Wadsworth
In October 2002, food labels
began to regulate the term
“organic” on foods grown in
the United States. To use
USDA organic seal:
• Raw products must be
100% organic.
• Processed foods must
contain 95% organic
ingredients.
© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
Why Choose a Farmer’s
Market?
• They help develop a food culture.
• Foods are less processed and less
packaged.
• Foods are usually fresher.
• Encourages healthier food choices
by promoting seasonal fruits and
vegetables.
• Boosts the local economy.
© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
New Technologies on the
Horizon
• Irradiation: the process of exposing a
substance to low doses of radiation,
using gamma rays, X-rays, or electricity
(electron beams) to kill insects,
bacteria, and other potentially harmful
microorganisms.
• Unique radiolytic products:
substances unique to irradiated food
and apparently created during the
process of irradiation.
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New Technologies on the
Horizon
• The FDA requires that
the labels of all irradiated
foods carry this
internationally known
radura symbol for
irradiation.
• The circle in the middle
represents an energy
source; the five breaks in
the outer circle symbolize
rays generated by the
energy source; and the
two petals signify food.
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New Technologies on the
Horizon
Farmers bred corn as we
know it today from wild
corn
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New Technologies on the
Horizon
• Genetic engineering: the process of altering the
genes of a plant in an effort to create a new plant
with different traits.
 This process of recombining genes is also
known as recombinant DNA (rDNA) technology;
a form of biotechnology.
• Transgenetics: the process of transferring genes
from one species to another unrelated species.
• Biotechnology: the science that alters the
composition and characteristics of biological
systems, organisms, or foods by manipulating
their genetic makeup.
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© 2007 Thomson - Wadsworth
© 2007 Thomson - Wadsworth
Benefits/Risks of Genetic
Engineering
• Potential Benefits:
 Increased nutritional
value of staple foods
 Reduced
environmental impact
 Increased fish yield
 Increased nutrient
absorption by
livestock
 Tolerance of poor
environmental
conditions
• Potential Risks:
Inadequate controls
Transfer of allergens
Unpredictability
Undesired gene
movement
 Environmental
hazards




© 2007 Thomson - Wadsworth
Domestic and World Hunger
• Infants can be the first to
show the signs of
undernutrition due to
their high nutrient needs.
• No famine, no flood, no
earthquake, no war has
ever claimed the lives of
250,000 children in a
single week.
• Yet malnutrition and
disease claim that
number of child victims
every week.
© 2007 Thomson - Wadsworth
Domestic and World Hunger
•
•
Food security: access by all people
at all times to enough food for an
active, healthy life and at a minimum
includes the following:
 The ready availability of nutritionally
adequate and safe foods.
 The ability to acquire personally
acceptable foods in a socially acceptable
way.
Hunger is related to poverty.
•
Food is available but is not accessible to
the poor who have neither land nor
money.
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Feeding the hungry—in the
U.S.
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Domestic and World Hunger
• Food banks: nonprofit community organizations that
collect surplus commodities from the government and
edible but often unmarketable foods from private
industry for use by nonprofit charities, institutions, and
feeding programs at nominal cost.
• Poverty: the state of having too little money to meet
minimum needs for food, clothing, and shelter. The U.S.
Department of Agriculture defines the poverty level in
the United States as an annual income of $19,350 for a
family of four.
• Second harvest: a national food banking network to
which the majority of food banks belong.
• Multinational corporations: international companies
with direct investments and/or operative facilities in
more than one country. U.S. oil and food companies are
examples.
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Domestic and World Hunger
• Famine: widespread lack of access to food caused by
natural disasters, political factors, or war; characterized
by a large number of deaths due to starvation and
malnutrition.
• Malnutrition: the impairment of health resulting from
a relative deficiency or excess of food energy and
specific nutrients necessary for health.
• Under-5-mortality rate (U5MR): the number of
children who die before the age of five for every 1,000
live births.
• Undernutrition (also called hunger): as used in this
discussion, a term that describes the domestic and
world food problem of a continuous lack of the food
energy and nutrients necessary to achieve and maintain
health and protection from disease.
• UNICEF: the United Nations International Children’s
Emergency Fund, now referred to as the United Nations
Children’s Fund.
© 2007 Thomson - Wadsworth