food: it shouldn’t be a mystery
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Food: It Shouldn’t Be a Mystery. Alan M. Tart Regional Retail Food Specialist U.S. Food and Drug Administration Atlanta, GA. Objectives. Name several examples of chemical, physical, and biological hazards found in food Review principles of microbiological growth & survival - PowerPoint PPT PresentationTRANSCRIPT
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Food: It Shouldn’t Be a Mystery
Alan M. TartRegional Retail Food SpecialistU.S. Food and Drug AdministrationAtlanta, GA
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Objectives
Name several examples of chemical, physical, and biological hazards found in food
Review principles of microbiological growth & survival
Identify at least one nutritional risk in food Discuss how to prevent, eliminate, or
reduce hazards/risks of concern
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Foodborne Illness in the U.S.
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The Problem – Foodborne Illness
Estimated 76 million illnesses
325,000 hospitalizations annually; hospital stays estimated at more than $3 billion
and 5,000 deaths!
Mead et al., Emerg. Infect. Dis. 5:607-625
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Factors Affecting Foodborne Illness in the U.S.
Globalization of the food supply
Food consumption patterns
Methods/Surveillance/Awareness
Changing production and processing practices
Evolution of new strains Increased longevity
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Controlling Food Safety Hazards
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Hazard
A physical, chemical, or biological property that may cause an unacceptable consumer health risk.
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Physical Hazards Poor handling
procedures in the food flow Examples: plastic,
bones, wood, glass, metal fragments,
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Naturally Occurring Chemical Hazards
Scombrotoxin Ciguatera Toxin Shellfish Toxins Tetrodotoxin Toxic Mushrooms Allergens
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Biological Hazards
Includes bacterial, viral, and parasitic organisms
Dennis Kunkel
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Percentage of Foodborne Illness Attributable to Known Pathogens
Viruses67%
Protozoa3%
Bacteria30%
Mead et al., 1999
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Bacteria, Viruses, and Parasites – What’s the Difference?
Bacteria grow in food and in the body Bacterial Infection vs. Intoxication
Viruses and parasites cannot grow in food, only in the body.
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Factors Needed for Bacterial Growth
Food Acidity Time Temperature Oxygen Moisture – Available Water
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Oxygen Requirements of Bacteria
Aerobic AnaerobicFacultative
Oxygen Dependent Oxygen Intolerant
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Vegetative Bacteria Found on many raw animal foods (meat, fish,
eggs, milk), as well as processed foods
Examples Salmonella E. coli O157:H7 Listeria monocytogenes Vibrio spp.
Control Measures Cooking No bare hand contact with RTE food Handwashing Not working when ill Temperature control
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Staphylococcus aureus High numbers of cells produce
heat stable toxin in ready-to-eat food
Caused by bare hand contact with ready-to-eat food and temperature abuse
Poor competitor on raw foods Normal reheating will not destroy
toxin
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Bacterial Spore Formation Spore – survival mechanism for certain bacteria
Heat resistance exceeds normal cooking temperatures
Spore-forming organisms C. perfringens C. botulinum B. cereus
Control Measures Proper cooling Hot and cold holding
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Clostridium botulinum Proteolytic strains of Type A and B
will not grow below 10°C (50°F) Non-proteolytic strains of type B
and E will not grow below 3.3°C (38°F)
C. botulinum will not grow at a water activity of 0.94 or less
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Recent Botulism Outbreaks Most cases of botulism are due to home-
prepared foods Nearly all of the recent botulism
outbreaks due to commercial foods are the result of extreme temperature abuse of refrigerated foods (2 or more days at room temperature)
Outbreaks due to commercially processed low acid canned foods are rare
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Recent Botulism Outbreaks Refrigerated pasta sauce in a plastic
pouch in a cardboard carton Refrigerated bean dip in a 16 oz plastic
tub with a snap fit lid Garlic in oil Sautéed onions left in a warm skillet
overnight Frozen shredded potato patty Refrigerated carrot juice in a plastic
bottle Baked potato wrapped in foil
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Foodborne Viruses
Hepatitis A 83,000 cases (5% foodborne)
Noroviruses Formally known as Norwalk-like viruses 23M cases (40% foodborne) Noroviruses are the #1 cause of foodborne
illness in the U.S. (67%) Example outbreaks
Other virusesMead et al., 1999
F.P. Williams, U.S. EPA
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Viruses and Cooking
Viruses display variable resistance to heat
Important controls No bare hand contact with ready-to-
eat food Proper handwashing Not preparing food when ill
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Why Viruses are Such a Problem
10,000,000 - # of viral particles you start with in 1 ml of feces 1,000,000 - # of virus particles left after properly
washing your hands (2 log reduction) (Ayliffe et al., 1978)
100,000 - # of virus particles transferred from an ungloved hand to food (10%) (Montville, 2001)
In contrast, it takes ~10 virus particles to make you sick
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Behavioral Causes of Foodborne Illness
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Foodborne Illness Risk Factors
Food from Unsafe Sources Inadequate Cooking Improper Holding Temperatures Contaminated Equipment/Cross
Contamination Poor Personal Hygiene
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Food from Unapproved Source
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Food from Unapproved Source
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Food from Unapproved Source
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Unapproved Cheese Product
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CDC’s EHS NET OUTBREAK/ NONOUTBREAK STUDY - Contributing Factors Identified in Outbreaks,EHS-NET, 2002-2003
C- Contamination FactorsP- Proliferation FactorsS- Survival Factors
Infected Person HandlingFood
Bare Hand Contact Holding
Food at Room Temperature
Insufficient Time/Temp. During Initial Cooking
Cross Contamination from Raw Animal Food
Raw Food Contaminated at Source
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Nutritional Risks in Food
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Nutritional Risk in Food
Obesity epidemic Genetic causes Environmental causes
Health risks associated with obesity
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Questions?
Alan M. TartRegional Retail Food Specialist
U.S. Food and Drug Administration60 8th Street, N.E.Atlanta, GA 30309
[email protected](404) 253-1267