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 Presentation


  • Food: It Shouldnt Be a MysteryAlan M. TartRegional Retail Food SpecialistU.S. Food and Drug AdministrationAtlanta, GA

  • Objectives

    Name several examples of chemical, physical, and biological hazards found in food Review principles of microbiological growth & survivalIdentify at least one nutritional risk in foodDiscuss how to prevent, eliminate, or reduce hazards/risks of concern

  • Foodborne Illness in the U.S.

  • 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

  • Factors Affecting Foodborne Illness in the U.S.Globalization of the food supplyFood consumption patternsMethods/Surveillance/AwarenessChanging production and processing practicesEvolution of new strainsIncreased longevity

  • Controlling Food Safety Hazards

  • HazardA physical, chemical, or biological property that may cause an unacceptable consumer health risk.

  • Physical HazardsPoor handling procedures in the food flowExamples: plastic, bones, wood, glass, metal fragments,

  • Naturally Occurring Chemical HazardsScombrotoxinCiguatera ToxinShellfish ToxinsTetrodotoxinToxic MushroomsAllergens

  • Biological HazardsIncludes bacterial, viral, and parasitic organisms

    Dennis Kunkel

  • Percentage of Foodborne Illness Attributable to Known PathogensMead et al., 1999

  • Bacteria, Viruses, and Parasites Whats the Difference?Bacteria grow in food and in the bodyBacterial Infection vs. Intoxication Viruses and parasites cannot grow in food, only in the body.

  • Factors Needed for Bacterial GrowthFoodAcidityTimeTemperatureOxygenMoisture Available Water

  • Oxygen Requirements of BacteriaAerobicAnaerobicFacultativeOxygen DependentOxygen Intolerant

  • Vegetative BacteriaFound on many raw animal foods (meat, fish, eggs, milk), as well as processed foods ExamplesSalmonellaE. coli O157:H7Listeria monocytogenesVibrio spp.

    Control MeasuresCookingNo bare hand contact with RTE foodHandwashingNot working when illTemperature control

  • Staphylococcus aureusHigh numbers of cells produce heat stable toxin in ready-to-eat food Caused by bare hand contact with ready-to-eat food and temperature abusePoor competitor on raw foodsNormal reheating will not destroy toxin

  • Bacterial Spore FormationSpore survival mechanism for certain bacteria Heat resistance exceeds normal cooking temperatures Spore-forming organismsC. perfringensC. botulinumB. cereus Control MeasuresProper coolingHot and cold holding

  • Clostridium botulinumProteolytic strains of Type A and B will not grow below 10C (50F)Non-proteolytic strains of type B and E will not grow below 3.3C (38F)C. botulinum will not grow at a water activity of 0.94 or less

  • Recent Botulism OutbreaksMost cases of botulism are due to home-prepared foodsNearly 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

  • Recent Botulism OutbreaksRefrigerated pasta sauce in a plastic pouch in a cardboard cartonRefrigerated bean dip in a 16 oz plastic tub with a snap fit lidGarlic in oilSauted onions left in a warm skillet overnightFrozen shredded potato pattyRefrigerated carrot juice in a plastic bottle Baked potato wrapped in foil

  • Foodborne VirusesHepatitis A83,000 cases (5% foodborne)Noroviruses Formally known as Norwalk-like viruses23M cases (40% foodborne)Noroviruses are the #1 cause of foodborne illness in the U.S. (67%)Example outbreaksOther viruses

    Mead et al., 1999F.P. Williams, U.S. EPA

  • Viruses and CookingViruses display variable resistance to heatImportant controlsNo bare hand contact with ready-to-eat foodProper handwashingNot preparing food when ill

  • Why Viruses are Such a Problem10,000,000 - # of viral particles you start with in 1 ml of feces1,000,000 - # 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

  • Behavioral Causes of Foodborne Illness

  • Foodborne Illness Risk FactorsFood from Unsafe SourcesInadequate CookingImproper Holding TemperaturesContaminated Equipment/Cross ContaminationPoor Personal Hygiene

  • Food from Unapproved Source

  • Food from Unapproved Source

  • Food from Unapproved Source

  • Unapproved Cheese Product

  • CDCs EHS NET OUTBREAK/ NONOUTBREAK STUDY - Contributing Factors Identified in Outbreaks,EHS-NET, 2002-2003C- Contamination FactorsP- Proliferation FactorsS- Survival Factors

    Infected Person HandlingFoodBare Hand ContactHolding Food at Room TemperatureInsufficient Time/Temp. During Initial CookingCross Contamination from Raw Animal FoodRaw Food Contaminated at Source

  • Nutritional Risks in Food

  • Nutritional Risk in FoodObesity epidemicGenetic causesEnvironmental causesHealth risks associated with obesity

  • Questions?Alan M. TartRegional Retail Food SpecialistU.S. Food and Drug Administration60 8th Street, N.E.Atlanta, GA 253-1267

    The contributing factors most often identified in all the outbreaks were C12, handling by an infected person or carrier of pathogen and C10 Bare-handed contact by handler/worker/prepare. P1, allowing foods to remain at room or warm outdoor temperature for several hours is the most often identified proliferation factor. And S1, Insufficient time and/or temperature during initial cooking/heat processing is the most often identified survival factor.

    And S1, Insufficient time and/or temperature during initial cooking/heat processing is the most often identified survival factor.

    These contributing factors are interesting in light of the agents involved in the outbreaks evaluated. You would expect more contamination factors to be identified in this group of evaluations given the agents involved in the outbreaks. With 47% of the outbreaks involving a viral agent one would expect to see more contamination factors identified.


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