1 Food: It Shouldn’t Be a Mystery Alan M. Tart Regional Retail Food Specialist U.S. Food and Drug Administration Atlanta, GA

2 Objectives Name several examples of chemical, physical, and biological hazards found in food Review principles of microbiological growth & survival Discuss how to prevent, eliminate, or reduce hazards/risks of concern

3 Foodborne Illness in the U.S.

4 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:

5 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

6 Food Safety Hazards

7 Hazard A physical, chemical, or biological property that may cause an unacceptable consumer health risk.

8 Physical Hazards Poor handling procedures in the food flow Examples: plastic, bones, wood, glass, metal fragments,

9 Naturally Occurring Chemical Hazards Scombrotoxin Ciguatera Toxin Shellfish Toxins Tetrodotoxin Toxic Mushrooms Allergens

10 Biological Hazards Includes bacterial, viral, and parasitic organisms Dennis Kunkel

11 Percentage of Foodborne Illness Attributable to Known Pathogens Mead et al., 1999

12 Bacteria, Viruses, and Parasites – What’s the Difference? Bacteria grow in food and in the body Types of illnesses Bacterial Infection Intoxication Toxicoinfection (toxin-mediated infection) Viruses and parasites cannot grow in food, only in the body.

13 Factors Affecting Bacterial Growth

14 Factors Needed for Bacterial Growth Food Acidity Time Temperature Oxygen Moisture – Available Water

15 Food (Nutrients) Protein Carbohydrates (sugars) Fats Vitamins Minerals

16 Acidity (pH) pH is the measure of the hydronium ion (H + ) concentration of a product. pH scale is 0-14 Below 7 is acidic, 7 is neutral, above 7 is basic Most bacteria prefer to grow in a relatively neutral environment. Foods may be made shelf stable by adding acid. At a pH of 4.1 or below, foodborne bacterial pathogens do not grow but may survive.

17 Approximate pH Values of Some Foods

18 Time and Temperature Basis for most food safety rules and regulations. Easily monitored and implemented. Used to control almost all potential biological hazards except viruses.

19 Time and Temperature Temperature Danger Zone 40°F – 140°F* *Consumer guidance

20 Time and Temperature

21 Oxygen Requirements of Bacteria AerobicAnaerobicFacultative Oxygen DependentOxygen Intolerant C. botulinum Lactic acid bacteria L. monocytogenes Pseudomonas E. coli

22 Moisture – Water Activity Amount of water available for bacteria to “live” or “grow” Generally, the lower the water activity, the lower the growth rate of organisms The minimum water activity threshold for bacterial pathogen growth in food is 0.87 or less.

23 Water Activity of Some Foods

24 Other Factors Interaction of pH and water activity Also called “hurdle technology” Competitive microflora

25 Comparing Vegetative, Spore- forming, & Toxin-producing Bacteria

26 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

27 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

28 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

29 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

30 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

31 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

32 Which would more likely have toxins in it if temperature-abused?

33 Which of following presents a higher risk of causing botulism? A.B.C.

34 Viruses

35 Foodborne Viruses Hepatitis A 83,000 cases (5% foodborne) Noroviruses (NoV) Formally known as Norwalk-like viruses Responsible for >50% of all foodborne gastroenteritis outbreaks in U.S. Est. to be as frequent as Salmonella in causing illness and death worldwide Other viruses Mead et al., 1999 F.P. Williams, U.S. EPA

36 Why Viruses are Such a Problem 1,000,000,000,000 - # of viral particles you start with in 1 ml of feces* 10,000,000,000 - # of virus particles left after properly washing your hands (2 log reduction) (Ayliffe et al., 1978) 1,000,000,000 - # of virus particles transferred from an ungloved hand to food (10%) (Montville, 2001) In contrast, it takes 1-10 virus particles to make you sick* *Teunis & Moe, 2008

37 Control of Viruses NoV survives heating at 140 ° F for 30 minutes Inactivated by boiling at 212 ° F Hand sanitizers/antiseptics ineffective Important controls No bare hand contact with ready-to-eat food Proper handwashing Not preparing food when ill

38 Parasites

39 Parasites - Examples Anisakis Giardia Cryptosporidium Cyclospora Toxoplasma gondii Trichinella spiralis Taenia saginata/Taenia solium (Tapeworms)

40 Behavioral Causes of Foodborne Illness

41 Foodborne Illness Risk Factors Food from Unsafe Sources Inadequate Cooking Improper Holding Temperatures Contaminated Equipment/Cross Contamination Poor Personal Hygiene

42 Food from Unapproved Source

43 Food from Unapproved Source

44 Food from Unapproved Source

45 Unapproved Cheese Product

46 CDC’s EHS NET OUTBREAK/ NONOUTBREAK STUDY - Contributing Factors Identified in Outbreaks, EHS-NET, C- Contamination Factors P- Proliferation Factors S- Survival Factors Infected Person Handling Food 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

47 Applying to the Classroom

48 Applicability to the Classroom The effect of water and temperature on metabolic rates of living things The use of acids and salts in real world applications Bacterial growth and the effect of competition for available nutrients/food Adaptation Basic infection control

49 Questions? Alan M. Tart Regional Retail Food Specialist U.S. Food and Drug Administration 60 8 th Street, N.E. Atlanta, GA (404)