New Strains of Bacteria Cook Up Problems

All of us have recipes that have been passed down through our families. Unknowingly, we may use or give others outdated recipe directions inconsistent with what we now know about food safety. Or we may assume people know the latest food safety guidelines. We may think everyone understands, for example, when we share a recipe that says, “cook until done.”

New bacteria have emerged and others have gotten stronger since some of our favorite recipes were developed. For example, the U.S. Public Health Service cited E. coli O157:H7, Salmonella, Listeria monocytogenes and Campylobacter jejuni as the four most serious foodborne pathogens in the United States. Twenty years ago, three of these – Campylobacter, Listeria and E. coli O157:H7 – were not even recognized as sources of foodborne illness.

Here are some general checkpoints for evaluating recipes for food safety that come in part from U.S. Department of Agriculture (USDA) recommendations:

Oven Temperatures
Use a minimum oven temperature of 325 degrees F for cooking meat, poultry and casseroles containing them. Lower temperatures may not heat the food fast enough to prevent bacterial growth.


A hundred years ago, it was common to see a recipe for egg water to cure vomiting. Today, we would no longer consider giving a sick family member a glass of egg white mixed with water.

However, without thinking, we may still follow the unsafe practices of:

  • Licking the cake batter from the bowl
  • Tasting raw cookie dough
  • Making ice cream with raw eggs 

Consider the following when cooking with eggs:

  • Cook eggs – whether scrambled, fried, poached, soft-cooked, made into an omelet, etc. – until the yolk and white are firm, not runny.
  • Avoid recipes in which eggs remain raw or are only partially cooked. Examples could include Caesar’s salad dressing; mousses; chiffons; homemade ice cream, mayonnaise or hollandaise sauce.
  • Heat cooked egg bases for recipes, such as custard (baked and stirred) and quiche to an internal temperature at 160 degrees F. At this temperature, a knife inserted near the center of a quiche or custard comes out clean. For a stirred custard, the mixture will coat a metal spoon.
  • Eggnogs and homemade ice creams can be safely made using a stirred custard base. Chill the cooked custard base thoroughly before freezing for ice cream to assure it rapidly reaches a safe temperature.
  • Although commercial pasteurized egg products can be used in place of raw eggs in recipes such as homemade ice cream, for optimal safety it’s safest to start with a cooked base that has been heated to an internal temperature of 160 degrees F. When serving people at high risk for food-borne illness such as young children, older individuals, people with an illness and pregnant women, it is best to use a cooked egg base.

Meat, Poultry
Judging meat doneness by whether it is brown inside is not always a reliable indicator of a safe internal temperature.

The Food Safety Educator, a publication of the USDA Food Safety and Inspection Service, shares the following story:

  • Wegmans Food Markets Inc., a grocery chain in New York and Pennsylvania, launched a campaign to educate consumers about the importance of cooking ground beef to 160 degrees F.
  • A poster used in an in-store demonstration showed two burgers, one pink and one brown. “Which is done?” the poster asked.
  • The poster provided the answer: the pink burger had been cooked to 160 degrees F, the brown burger to 140 degrees F. Wegmans Director of Consumer Affairs, Mary Ellen Burris, noted, “The only way to really know if it’s done is to use a meat thermometer.”
  • Also, as a part of safe preparation, do not partially cook or brown foods to cook later.
  • Any bacteria present will not be destroyed.
  • If you are cooking food partially in the microwave, oven or stove to reduce grilling time, pre-cook it immediately before grilling.

Use these recommended internal temperature for doneness:

Ground Meat and Poultry (prepared as patties, meatloaf, etc.)
Beef, veal, lamb, pork: 160 degrees F
Chicken, turkey: 165 degrees F

NOTE: Thoroughly cook ground meat or poultry BEFORE combining it with other ingredients in casseroles, meat sauces, etc.

Fresh beef, veal and lamb:
Roasts and steaks:
  Medium rare: 145 degrees F
  Medium: 160 degrees F
  Well-done: 170 degrees F

Fresh pork:
Chops, roasts, ribs:
  Medium: 160 degrees F
  Well-done: 170 degrees F

Fresh (raw): 160 degrees F
Cured, fully cooked, (to reheat): 140 degrees F

Whole chicken, turkey: 180 degrees F
Poultry breasts, roasts: 170 degrees F
Poultry thighs, wings: 180 degrees F

(Juices will run clear when cut)

Using a food thermometer helps assure that your food reaches a safe internal temperature. A thermometer also helps you avoid overcooking a food and affecting its taste and quality.

Marinades help flavor meat and poultry.

They do not kill bacteria. Here are some general guidelines for safely using marinades:

  • Marinate in a covered container in the refrigerator, not on the counter. A glass container is a safe choice for marinating.
  • Acidic ingredients in some marinades such as wine, vinegar and lemon juice could react with certain metallic or glazed ceramic containers and leach into the food being marinated.
  • Marinating time in the refrigerator should not exceed the recommended storage time for that type and cut of fresh meat or poultry.
  • If you are not certain how long to marinate a particular food – for best safety and quality – limit time to 24 hours or less.
  • If some of the marinade is to be used for basting during cooking or as a sauce on the cooked food, reserve a portion of the marinade and store in the refrigerator until ready to use.
  • Do not put raw meat or poultry in it.
  • When basting, do not recontaminate fully cooked meat or poultry by adding sauce with a brush that has been used on raw or undercooked foods.
  • For greatest safety, do not re-use leftover marinade that has been in contact with raw meat or poultry.

Henry Ford, the person behind the Model T car, is quoted as saying, “Anyone who stops learning is old, whether at 20 or 80. Anyone who keeps learning stays young. The greatest thing in life is to keep your mind young.”

It might also be said that anyone who keeps learning about food safety stays healthy. The next time you make or give others a recipe, check to see if you should do a food safety update.

8/10/2006 7:44:56 PM
Rate This Article:

Have a question or comment about the information on this page?

Innovate . Educate . Improve Lives

The LSU AgCenter and the LSU College of Agriculture