Food Safety Hazards

Objectives Review principles of microbiological growth & survival. Give examples of chemical, physical, and biological hazards found in food. Discuss control measures used at retail to prevent bacterial, viral, and protozoan foodborne illness.

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

Chemical Hazards Natural - mycotoxins, scombroid and ciguatera toxin, toxic mushrooms, shellfish toxins, allergens Added - medicines, food or color additives, pesticides, cleaners, sanitizers

Naturally Occurring Chemical Hazards Finfish (e.g., tuna, mahi mahi, grouper, snapper) often implicated Can cause neurological, cardiovascular, and gastrointestinal symptoms Examples: Scombrotoxin Ciguatera Please see pg. 67, Operators Guide – Seafood References

Control of Chemical Hazards Natural occurring chemicals Approved sources of food Added chemicals- Standard Operating Procedures (SOPs) Proper storage of chemicals Labeling of chemicals Restriction of chemicals in facility

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

Control of Physical Hazards Standard Operating Procedures Buyer specifications Equipment- light shields Facility- maintenance of physical surroundings Buyer specifications- no bones in fish Equipment- Facility- floors, walls, ceilings maintained to prevent paint, etc from getting in food

Biological Hazards Include bacterial, viral, and parasitic organisms

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.

Key Factors that affect Bacterial Growth Food – Nutrients Acidity Time Temperature Oxygen Moisture

Factors for Growth: Food - Nutrients Protein Carbohydrates (sugars) Fats Vitamins Minerals

Factors for Growth: Acidity of a Product - pH pH is the measure of the 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. What common foods and ingredients may be used to lower the pH of the final product? Below what pH are bacteria unable to grow (but may survive)? pH 4.6

Approximate pH Values of Some Foods

Factors for Growth: 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 Bacteria can’t grow (but may survive) in an environment with aw of 0.85 or less

Water Activity of Some Foods 0.85

Factors for Growth: Time and Temperature

Time and Temperature Key control measures of biological hazards in FDA Food Code Used to control almost all potential biological hazards except viruses Easily monitored and food quality minimally affected

Time and Temperature (2001 Food Code) Danger Zone 41F- 140F Cooking raw animal foods 145F 15 sec- fish, meat, game, eggs 155F 15 sec-pork, ratites, injected and comminuted meats, pooled eggs 165F 15 sec- poultry, stuffed fish, meat, pasta, poultry

Time and Temperature (2001 Food Code) Cooling of PHF (potentially hazardous food) From 140F to 70F within 2 hours and From 70F to 41F, or below within 4 hours

Time and Temperature (2001 Food Code) Hot holding of PHF 140F Cold holding of PHF 41F Time as a Public Health Control 4 hours

Potentially Hazardous Food (PHF) 2001 Definition A food that requires temperature control because it supports the . . . Rapid & Progressive Growth of pathogens; Growth & Toxin Production of C. botulinum; and/or Growth of S. Enteritidis in Shell Eggs. INCLUDED: Animal Foods, Heat Treated Plant Food, Raw Seed Sprouts, Cut Melons, Garlic in Oil Refer to Definition of Potentially Hazardous Food in Chapter 1. (Page 12) Rapid Growth - multiplication in Hours Vs. Days Progressive Growth - Exponential growth leading to numbers that may cause illness. C. bot toxin is of concern. Consider the outbreaks relating to baked potatoes back in the 70’s. Garlic in oil is also a concern with regards to growth and toxin production of C. bot.

Food that is NOT a PHF (based on 2001 Food Code) aw of 0.85 or less pH of 4.6 or less Hermetically sealed container Lab evidence A food that can cause illness but does not support growth of pathogens (contaminated or otherwise adulterated food) An air-cooled hard-boiled egg with shell intact Water activity and pH have long been determining factors in decision making of whether or not a food is potentially hazardous. Food in hermetically sealed containers that have not been opened is not PHF. Laboratory evidence may be used to determine if a food will support the growth of pathogens in a food. Example, some pies have been deemed non-PHF although the water activity and pH are above the critical limits. An example of a food that can cause illness but does not support growth of pathogens is apple juice. E. coli O157:H7 has been implicated in outbreaks involving low pH apple juice. The organism may be present in the apple juice, but it will not grow at such a low pH. pH of apple juice may be 3.8. (See Definition (61)(c)(vi), page 12.)

PHF (TCS Food) does not include . . . Air-cooled, hard boiled egg – shell intact Shell eggs treated to destroy all salmonellae (pasteurized shell eggs) A food that does not support the growth of pathogenic microorganisms even though they may be present Some foods that are refrigerated for quality, not safety

PHF/TCS Food or not? Exercise 1) Swiss cheese 2) Raw seed sprouts 3) Pasteurized skim milk 4) Opened canned green beans 5) Cut watermelon 6) Garlic-in-oil mixture 7) Unpasteurized orange juice 8) Pre-washed lettuce salad 9) Sour cream 10) 1000 Island Dressing 11) Butter 12) Margarine 13) Pumpkin pie Instruct student to take a few minutes to determine if foods are PHF or not. They may refer back to slides #16 and #18 (Aw and pH tables)

PHF/TCS Food or not? Exercise answers 1) Swiss cheese- yes 2) Raw seed sprouts-yes 3) Pasteurized skim milk-yes 4) Opened canned green beans-yes 5) Cut watermelon-yes 6) Garlic-in-oil mixture-yes 7) Unpasteurized orange juice-no 8) Pre-washed lettuce salad-no 9) Sour cream-no, if commercial 10) 1000 Island Dressing-no, if commercial 11) Butter-yes 12) Margarine-no 13) Pumpkin pie-yes

Vegetative Bacteria Found on many raw animal foods (meat, fish, eggs, milk), as well as processed foods Examples Salmonella Campylobacter jejuni E. coli O157:H7 Listeria monocytogenes Vibrio spp. Control Measures Cooking No Bare Hand Contact with RTE Handwashing Employee Health Temperature Control Tell student to see HACCP Operator’s Guide pages 63-65 for a complete list of pathogens and associated foods Salmonella and Campylobacter in raw poultry Salmonella enteriditis in raw eggs E. Coli 0157:H7 in raw ground beef Listeria monocytogenes in ready to eat foods such as deli meats

Bacterial Spore-Formers 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 Tell students to see page 65in HACCP Regulators Guide for a complete list of pathogens and associated foods C. perf in cooked meat and poultry C. Botulinum in vacuum packaged, ROP foods B. Cereus in meat, poultry and starchy foods

Staphylococcus aureus High numbers of cells produce heat stable toxin in RTE food Caused by bare hand contact with RTE food and temperature abuse Poor competitor on raw foods Reheating will not destroy toxin

Foodborne Viruses Hepatitis A – 83,000 cases (5%)* Noroviruses (formally known as Norwalk-like viruses) – 23M cases (40%)* *percent foodborne Mead et al., 1999

Foodborne Viruses Shed primarily in human feces Viruses in food is evidence of fecal contamination Key is to prevent fecal contamination of food

Viruses and Cooking Viruses display variable resistance to heat No bare hand contact with RTE, proper handwashing, and implementation of effective employee health policies are important control measures

Fungi Yeasts Molds Mushrooms Yeasts are generally not pathogenic but can cause food spoilage. Fungi problems are more commonly found outside the body – dermatophytoses (athlete’s foot) and zoonotic fungi (ringworm) An important exception is the yeast causing candidiasis, a serious mouth infection Most molds are not pathogenic, some produce mycotoxins such as alflatoxin

Parasites Live within another organism or host Trichinella spiralis Entamoeba histoytica Giardia lambia Cryptosporidium spp. Control parasites through proper cooking and using safe water supplies T. spiralis- roundworm in pork and other meats E. histolytica- amoeba in contaminated water- Montezuma’s revenge, traveler’s diarrhea G. lambia- protozoan transmitted form infrected food workers and contaminated water Control parasites via cooking, safe water supplies

The Problem – Foodborne Illness Estimated 76 million illnesses 325,000 hospitalizations annually; hospital stays estimated at more than $3 billion and 5,000 deaths! Why are we concerned about pathogens in food? This is why Mead et al., Emerg. Infect. Dis. 5:607-625

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

Salmonella Hepatitis A Infection – Salmonella Hepatitis A Campylobacter Norovirus Listeria Trichinella Anisakis Shigella Intoxication- C. botulinum B. cereus (Emetic) Staphylococcus Other- Scombrotoxin Ciguatoxin Toxin-Mediated Infections C. perfringens B. cereus (Diarrheal) E. Coli 0157:H7 Summary slide of pathogens of concern