Chapter Nineteen

Food Safety

Overview: Food Borne Illness

Great information from CDC: www.cdc.gov/foodborneburden/2011-foodborne-estimates.html
Several million cases of foodborne disease occur each year in the United States.
One in six Americans experience foodborne illness annually.
The great majority of these cases are mild and cause symptoms for only a day or two.
Some cases are more serious, and CDC estimates that there are 100-300,000 hospitalizations and 3-5,000 deaths related to foodborne diseases each year.
Those susceptible: infants and children, older adults, cancer patients, pregnant women, people taking immunosuppressant drugs, and those with liver disease diabetes, or HIV infection
Causes
- Mishandling food
- Increased interest in eating raw or undercooked foods
- Medications taken by people suppresses ability to combat food borne infectious agents
- Increased shelf life of foods (but more exposure to bacteria)
- Contamination from centralized kitchens

Organisms Causing Food Borne Illness

Bacterium

Organism
Campylobacter jejuni	Found on poultry, meat, and lamb
Salmonella	Found in raw meats, poultry, eggs, and fish; Multiplies at room temperature; causes Salmonellosis; number one pathogen that causes illness, hospitalization, and even deaths in the U.S.
Shigella	Transmitted via fecal-oral route; causes Shigellosis
Escherichia coli 0157:H7	Found in ground beef, fruits, and vegetables
Clostridium perfringens	Found throughout environment; multiplies in anaerobic conditions
Clostridium botulinum	Found throughout the environment; produces toxin; reproduces in anaerobic environment; causes Botulinism
Listeria monocytogenes	Found in unpasteurized milk and products made from unpasteurized milk; resists acid, heat, salt, nitrate, and refrigeration
Staphylococcus aureus	Found on skin and nasal pasages; can produce toxin
Yersinia enterocolitica	Found throughout environment; found in raw vegetables, meats, water, and unpasteurized milk
Vibrio vulnificus	Found in raw seafood
Vibrio parahaemolyticus	Found in brackish saltwater; high concentrations in oysters
Vibrio cholerae	Human carriers and found in contaminated waters; causes Cholera
Other bacteria...	Leptospia, Brucella, Cronobacter, and Giardia

Viruses

Organism
Noroviruses (e.g., Norwalk virus, Desert Shield virus, and Southampton virus)	Found in foods from contaminated water and soil; Shellfish and salad ingredients; number one viral agent causing foodborne illness
Hepatitis A	Shellfish (clams, oysters, and mussels) from polluted waters
Rotovirus	Spread by fecal-oral route; very common in small children

Parasites

Organism
Trichinella spiralis	Nematode found in pork and wild game; causes tricinellosis; also called "pork worm"; resides in intestinal epithelium
Anisakis simplex	Nematode found in raw fish (e.g., salmon and sardines); causes anisakiasis
Taenia solium (Tapeworm)	Cestodes found in raw beef, pork, and fish; causes cysticercosis (larval) and taeniasis (adult form)
Cyclospora cayetanesis	Protozoan found in fecal contaminated water; first isolated from contaminated from imported raspberries
Cryptosporidium	Protozoan found in contaminated drinking water; resistant to chlorination treatment
Toxoplasma gondii	Protozoan found in raw meat, contaminated fruits and vegetables, and in cat feces; causes toxoplasmosis

Other Organisms and Agents
Fungi	Examples: Molds (produce mycotoxins) and Ciguatera (in tropical fish)
Prions	Proteins that can cause infection (bovine spongiform encephalopathy) called mad cow disease

Food Preservation

Salt, sugar, smoke, and drying used for centuries to decrease free water needed by microorganisms
Fermentation used to produce environment (acidic) not conducive to bacterial growth
Pasteurization, sterilization, refrigeration, freezing, irradiation, canning, and chemical preservatives used today

Preventing Food Bourne Illness

World Health Organization Rules

Choose foods processed for safety
Cook food thoroughly
Eat cooked foods immediately
Store cooked foods immediately
Reheat cooked foods thoroughly

Avoid contact between raw and cooked foods
Wash hands repeatedly
Keep all kitchen surfaces meticulously clean
Protect foods from insects, rodents, and other animals
Use pure water

USDA Rules

Purchasing food
- Frozen food and perishable food picked out last
- Separate foods accordingly into plastic bags
- Purchase pasteurized milk and cheeses only
- Avoid damaged containers and food
Preparing food
- Thoroughly wash hands, countertops, kitchens utensils
- Thaw frozen foods in refrigerator 1-3 days, under cold running water, or in microwave oven
- Avoid sneezing over foods
- Carefully wash fruits and vegetables
- Carefully remove moldy portions of food or “when in doubt throw the food out”
- Use refrigerated ground meat within 1-2 day of purchase and frozen meat 3-4 months

Cooking food
- Beef, fish and pork cooked at temps of 160 degrees F (71 degrees C)
- Poultry at temps 180 degrees F (82 degrees C)
- Cook stuffing separate from poultry
- Once food is cooked consume it right away or store it at 40 degrees F (4 degrees C) within 2 hours
- Serve meat, poultry, and fish on a clean plate – not the plate that they were prepared on
Storing and reheating food
- Keep hot foods hot and cold foods cold
- Reheat leftovers to 165 degrees F (74 degrees C)
- Store peeled or cut produce in refrigerator
- Make sure refrigerator stays below 40 degrees F (4 degrees C)

Food Additives

Limit spoilage
Used to maintain safety and acceptability of foods by retarding the growth of microbes
Intentional food additives – additives knowing incorporated into food products by manufacturers
Incidental food additives – additives that appear in food products indirectly, from environmental contamination of food ingredients or during the manufacturing process
GRAS list – generally recognized as safe list – list of food additives that in 1958 were considered safe for consumption – monitored by FDA and additives can and have been removed from the list
Natural versus synthetic compounds
Researches suggest “we ingest at least 10,000 times more natural toxins produced by plants than we do synthetic pesticide residues”
Test for food safety
- NOEL – no observable effect level – the highest dose of an additive that produces no deleterious health effects in animals
- Delany Clause in the 1958 food amendments – prohibition of intentionally adding to foods a compound that was introduced after 1958 and causes cancer
Approval for a new food additive
FDA approval
- Manufacturers must give FDA information that
- Identifies the new additive
- Gives its chemical composition
- States how it is manufactured
- Specifies the laboratory methods used to measure its presence in the food supply at the amount intended use

Types of food additives:

Acidic and alkaline agents
- Flavor enhancing agents
- Preservatives
- Antioxidants
- Produce texture
Alternative sweeteners - Saccharine, sucralose, acesulfame potassium
Anticaking agents - Sodium benzoate, sorbic acid, calcium propionate
Antioxidants
- Helps delay food discoloration and helps keeps fats from turning rancid
- BHA (butylated hydroxyanisole) and BHT (butylated hydroxytoluene)
- Vitamin E (alpha-tocopherol)
- Vitamin C (ascorbic acid)
- Sulfites
Colors
Curing and pickling agents - Sodium and potassium nitrates and certain nitrites
Emulsifiers

Fat replacements - Paselli SA2, Dur-Low, Oatrim, Sta-Slim, 143 Stellar, and Z-trim
Flavor enhancers - MSG
Humectants
- To retain moisture, flavor, and texture
- Glycerol, propylene glycol, and sorbitol
Leavening agents
Maturing and Bleaching agents
- Hasten whitening (ex flour)
- Bromates, peroxides, and ammonium chloride
Nutritional Supplements
Stabilizers and Thiceners
Sequestrants
- Bind free chemical ions to prevent racidity
- EDTA and citric acid

Naturally Occurring Substances in Food Causing Illness

Safrole – sassafras, mace, and nutmeg – can cause cancer
Solanine – potato shoots and green spots on potato skins inhibit action of neurotransmitters
Mushroom toxins – cause mild health problems to coma and death
Avidin – found in raw egg white binds the vitamin biotin in a way that prevents its absorption
Thiaminase – found in raw fish, clams, and muscles destroys the vitamin thiamin
Tetrodotoxin – found in puffer fish and can cause respiratory paralysis
Protease inhibitor – found in raw oysters and inhibits digestive enzymes
Oxalic acid – found in spinach, strawberries, and sesame seeds binds calcium and iron in foods
Herbal teas – containing senna or comfrey can cause diarrhea and liver damage

Environmental Contaminants in Foods

Lead
Diotoxin
Mercury
Urethane
Polychlorinated Biphenyls