Food Safety - 5/13/97

Preventing Foodborne Illness

General Foodborne Illness
Evaluating Changes in Food
Safe Storage Temperatures
Cooking Thoroughly
Refrigerating Leftovers
Cleaning Surfaces
Cross Contamination
Re-heating Leftovers
Dating Labels
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Warm weather marks the beginning of our peak season for food poisonings and food infections. Bar-B-Qued meats may contain undercooked portions and bacteria present in the raw animal foods can be easily transferred to the cooked by using the same spatulas and plates. Picnic food is often not kept cold enough to prevent bacterial growth, and adequate handwashing is difficult when eating at parks.


While most victims suffer only short-term (1-8 days) digestive upsets, some food poisonings and food infections can result in permanent nerve damage, kidney failure, or death. These eight rules for safe food will significantly decrease your chance of becoming ill.

The basic rules for keeping food safe apply year-round; they are just more difficult to adhere to during warm weather. Also, warm temperatures promote microorganism growth so there is less room for error during our outside dining season.
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Food Safety

Microorganisms that cause illness (human pathogens) and their sometimes unusual entries into food can be alarming to consumers. This need not be. It is important to focus on the methods of prevention which are easily followed and inexpensive at the household level.

1. EXAMINE FOOD

Educate yourself about changes in food. Which scenarios are only quality changes and which indicate a possibly unsafe food?
Quality Changes:Browning, Drying out, Rancidity, Dissolving, Separations, Ice crystal damage in frozen foods, Expired dates on commercially manufactured foods.
Safety Changes:Bacteria, viruses, molds, or parasites present in the food in large enough numbers to overwhelm an individual's immune system.
Discard food with off-odors, visible slime, soft moldy food, canned foods with off odors, color, or texture. Discard these items so animals do not consume them.

PREVENTION OF SAFETY CHANGES FROM OCCURRING IN FOODS REQUIRES SPECIFIC BEHAVIOR FROM PEOPLE HANDLING IT

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2. KEEP HOT FOODS HOT AND COLD FOODS COLD

Warm is an unsafe temperature; human pathogens grow extremely well in warm, perishable foods. Store foods below 40F or above 140F. Do not consume perishable foods that have been held between 40 and 140F for more than 3 hours.

What is a perishable food? Perishable foods have amounts of moisture, protein, pH, and salts similar to conditions of the human body (human pathogens are well adapted to growing inside the human body).
Meats, poultry, fish, cooked vegetables, dairy products and eggs are examples of perishable foods.
Raw vegetables, fruits, breads, fruit juices, meat jerky, jam and jelly, candy, pickles, commercial salad dressings and mayonnaise, uncooked rice, uncooked pasta, uncooked oatmeal, dry breakfast foods, and unopened canned goods are examples of non-perishable foods.
Buffet lines: use hot plates, chaffing dishes, beds of ice, and keep rotating small amounts. Do not combine leftovers with fresh. Know if the perishable food has been in dangerous warm zone for over 3 hours; this is cumulative.

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3. COOK RAW MEATS, POULTRY, MILK, EGGS, AND SEAFOODS THOROUGHLY

These foods are naturally contaminated with pathogens. The general rule is to heat to 160F. Poultry is cooked to 180F for palatability but 160F is safe for it too. Check BBQ and microwaved foods carefully, uneven heating is common.

Heat resistant spores (clostridia and bacillus) are not killed during cooking, so store perishables safely (40 - 140F) or they will germinate, grow, and cause illness when the food is consumed.
Eggs are most often contaminated on the outside of the shell, but it is impossible to crack an egg without the insides touching the outside shell. Cook sound eggs until thick, not runny. Use those with cracked or checked shells in oven-baked recipes.
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4. COVER AND REFRIGERATE LEFTOVERS PROMPTLY

For quick cooling, setting the casserole in a pan of cold water cools it more rapidly than if it is only surrounded by cold air. Hot foods that have cooled enough so you can pick them up with bare hands may be placed in the refrigerator to cool if bowls are a maximum of 3" deep and jars a maximum of 1/2 gallon size. Larger containers cool too slowly to be safe.

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5. WASH HANDS AND WORK SURFACES WELL

Routine, thorough hand washing with soap and lots of water reduces fecal and most hand-nasal contamination.

Cutting boards, countertops and other surfaces should be scrubbed with soap and water and rinsed with a bleach-water solution after they have come in contact with raw meat, fish or poultry. 1 Tb bleach to 1 gal water gives 200 ppm available chorine which is deemed adequate for most household uses. How clean is your can opener?
Recent research has demonstrated that plastic boards need to be replaced when scarred and are at least as difficult to clean as wooden boards with ordinary scrubbing. However, since wooden boards are porus and cannot go into the dishwasher, they are not recommended for use with raw foods from animal orgin in a usual household setting.
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6. PREVENT CROSS-CONTAMINATION

Cross contamination occurs when an uncooked animal product touches foods which will be consumed without further cooking.

Do not contaminate foods with re-used shoppings bags or egg cartons. If you break eggs open on the edge of a counter or mixing bowl, you have contaminated those surfaces too (use a knife then place knife in dishwasher)
Washing poultry before using is a good way to splatter salmonellae over the work area and does not remove an important number of bacteria.
In bar-b-cuing or preparing fondue, cooked food should not be put on the plate that held the raw. Marinades should not be used for raw meat and poultry then for basting the meat near the end of cooking. Boil marinades if they are also to be served with the meat.
Is the same cutting board used for raw meats and salads?
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7. RE-HEAT LEFTOVERS THOROUGHLY

Note: This does NOT inactivate the toxin of S. aureus which is a very common foodborne illness organism in the U.S.. Heat treatments do not give assurance that an unsafe food is rendered safe, but it decreases the occurrence of foodborne illnesses from C. perfringens, C. botulinum, and Listeria especially. thus, it may be wise advice to give to someone at higher risk of foodborne illness such as those with compromised immune systems, those with chronic illnesses, pregnant women, the elderly, and the very young.

Heating until bubbling hot inactivates any heat labile toxins or live microorganisms that entered after the initial cooking. If food is placed on a table and then talked over, assume that pathogens from human mouths are present.
Even when microwaving leftovers for young children, it provides an "edge" against pathogens if they are bubbling hot and then cooled down. (Young children find waiting difficult. Cool quickly by setting plate on ice, or adding frozen peas.)
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8. CARE LABELS

Lawsuits have prompted some commercial food manufacturers to add directions on the care of their perishable foods. Following such directions will prevent the growth of pathogens in that food.
Unfortunatuely, care instructions designed to preserve the quality and prolong the shelf life of non-perishable foods such as salad dressings, packaged puddings, canned main dishes, etc. are often confused with those on perishable foods which are instructions necessary for safety. The result is a high proportion of non-perioshable foods being discarded because householders could not make the distinction between quality and safety issues.
Perishable and non-perishable foods are clearly defined in the Food Preservation and Safety reference book on the main menu. Check that list if you are unsure. Best if used by dates on non-perishable foods are for quality only.

Detailed information on foodborne illness is available on-line at www.foodnavigator.com This site originates in France, but is published on the web in English. It is sound, reliable information.


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