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15
Food Safety and
Technology: Impact
on Consumers
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Food-Borne Illness
• Symptom or illness from food or water that
contains an infectious agent or toxic
substance
• Commonly called food poisoning
• 76 million reported cases each year
• Over half unknown or unreported
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People at Risk
• Developing fetuses, infants, and young
children, whose immune systems are still
immature
• The very old and the frail elderly
• People with chronic illnesses (diabetes)
• People with acquired immunodeficiency
syndrome (AIDS)
• People who are receiving immune-systemsuppressing drugs (transplant recipients and
cancer patients)
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Government Regulators
• Multiple government agencies are involved in
ensuring the safety and quality of the food
supply:
• U.S. Department of Agriculture (USDA)
• U.S. Food and Drug Administration (FDA)
• Centers for Disease Control and Prevention
(CDC)
• U.S. Environmental Protection Agency (EPA)
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© 2011 Pearson Education, Inc.
Public Health Issue
• More foods are mass-produced
• Combination of ingredients from a much greater
number of sources
• Contamination can be difficult to trace
• Federal oversight has decreased
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Causes of Food-Borne Illnesses
• Food infections: consumption of food
containing living microorganisms
• Food intoxications: consuming food in which
microbes have secreted poisonous
substances called toxins
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Microbes Contaminate Food
• Bacteria and viruses are the most common
microbes causing food-borne illnesses
• Most common bacterial contaminants:
• Campylobacter jejuni
• Salmonella
• Viruses: hepatitis A and E, rotaviruses
ABC Video E. Coli at Home
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
Microbes Contaminate Food
• Helminths, commonly called worms, include
tapeworms, flukes, roundworms
• Parasite: benefits from and harms its host
(Giardia)
• Fungi: plant-like spore-forming organisms
(yeasts and molds)
• Prion: self-replicating protein particle that
causes mad cow disease or bovine spongiform
encephalopathy (BSE)
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
Microbes Release Toxins
• Toxins are responsible for illnesses
• Neurotoxins damage the nervous system, cause
paralysis
• Clostridium botulinum: found in bulging cans, foods
improperly canned at home, raw honey
• Enterotoxins target the gastrointestinal system,
cause severe diarrhea and vomiting
• Mycotoxins are secreted by fungi
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Toxins Without Microbes
• Poisonous mushrooms
• Marine toxins
• Solanine (greening process in potatoes)
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© 2011 Pearson Education, Inc.
Body Defense Mechanisms
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Antimicrobial enzymes in saliva
Hydrochloric acid in the stomach
Vomiting or diarrhea to expel the offender
Activate immune system: white blood cells
To diagnose a food-borne illness: obtain and
culture a specimen
• Keep the person hydrated and comfortable
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Microbes Multiply in Foods
• Temperature: 40−140°F (4−60°C) is known as
the “danger zone”
• Humidity
• Acidity
• Oxygen content
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Preventing Food-Borne Illness
When preparing foods at home, be sure to:
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Wash hands and kitchen surfaces often
Separate foods to prevent cross-contamination
Chill foods to prevent microbes from growing
Cook foods to their proper temperature
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
Preventing Food-Borne Illness
• Standard rule for storing leftovers:
2 hours/2 inches/4 days
• Foods should be cooked thoroughly
• Food should be thawed in the refrigerator
• When traveling: avoid raw foods, choose
bottled water without ice
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© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
Preserving Food
• Natural methods
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Salting
Sugaring
Drying
Smoking
Cooling
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Preserving Food
• More modern techniques include:
• Industrial canning
• Packaging techniques (aseptic)
• Preservatives (antioxidants, mold inhibitors,
sulfites, nitrites, nitrates)
• Irradiation
• Genetic modification
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
Food Additives
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Natural or synthetic
Flavoring agents
Colorings
Nutrients
Improve texture or moisture content
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Food Additives
• Flavoring agents: essential oils, extracts, or
spices
• Flavor enhancers: do not have flavor of their
own
• Examples include maltol and MSG
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Food Additives
• Food colorings
• Natural colorings beet juice (red color), betacarotene (yellow), caramel (brown)
• Tartrazine (FD&C yellow #5) causes an allergic
reaction in some people, and its use must be
indicated on the product packaging
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Food Additives
• Vitamins and other nutrients:
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Vitamins E and C (ascorbic acid): antioxidant
Iodine (table salt) helps to decrease goiter
Vitamin D and calcium for bone health
Folate (breads, cereals) to decrease neural tube
defects during fetal development
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Food Additives
• Texturizers, stabilizers, or emulsifiers to
improve the texture of foods
• Thickening agents
• Humectants maintain correct moisture levels
• Desiccants prevent moisture absorption from
the air
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© 2011 Pearson Education, Inc.
Safety of Food Additives
• Delaney Clause
• Generally Recognized as Safe (GRAS) list
• Adverse Reaction Monitoring System (ARMS)
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Food Residues
• Food residues: chemicals that remain in foods
despite cleaning and processing
• Persistent organic pollutants (POPs):
chemicals released into the atmosphere from
industry, agriculture, automobiles
• Mercury and lead: neurotoxins
• Industrial pollutants
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.
Pesticides
• Pesticides: protect against weeds, insects,
fungi; increase crop yields
• Insecticides, herbicides, fungicides
• Can be natural or synthetic
• Remain on foods, causing health risk
• Children: especially sensitive to pesticides
• EPA controls use of pesticides
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Growth Hormones
• Recombinant bovine growth hormone (rBGH):
genetically engineered growth hormone given
to cows
• Increases muscle mass; decreases fat
• Increases milk output
• Causes mastitis in cows, resulting in increased
antibiotic use in the cows
• Antibiotic-resistant bacterial strain: methicillinresistant Staphylococcus aureus (MRSA)
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Organic Foods
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Food grown without synthetic pesticides
Standards regulated by USDA
May have higher nutrient content
Insufficient evidence to support the claim that
organic foods are more nutritious than nonorganic foods
© 2011 Pearson Education, Inc.
© 2011 Pearson Education, Inc.