Perryman Nutrition Column: Egg Basics-Separate Fact from Fiction

Note to Reporters: The following column was written by Shirley Perryman. Perryman is an Extension specialist in the Colorado State University Department of Food Science and Human Nutrition. The department is part of the College of Applied Human Sciences. Perryman also is a registered dietitian.

While shopping at a farmers’ market I asked various vendors what the difference was between more expensive organic eggs and cheaper eggs available in the supermarket. Most were in agreement that the flavor of organic eggs is far superior to conventionally produced eggs. One producer spontaneously broke open a fresh egg tossing it from one hand to the other to demonstrate the firmness of the yolk. However, many of the vendors’ responses prompted me to wonder if the average consumer knows when an egg producer may be spouting bad information while selling good eggs. In an effort to separate fact from fiction check out the basics on buying and using eggs.

– Shell color is determined by the breed of the hen that lays the egg. White eggs are most common. Brown eggs are more expensive because the hens that lay them are bigger and require more food.
– The shell color has no effect on the nutrition of the egg.
– The fresher the egg, the cloudier the egg white. As the egg ages, the white becomes clearer and thinner.
– Egg yolk color is determined by what the chicken eats. Deep yellow yolks are typically from chickens that are fed yellow corn and alfalfa meal. Pale yellow yolks are from hens fed wheat or barley. Cage free chickens that forage and eat a variety of grains lay eggs with a deep orange-yellow color yolk.

– A large egg contains 70 calories, 6 grams of protein, and 5 grams of fat of which 2 grams are saturated fat. The white contains most of the protein and the yolk has all the fat.
– Eggs are excellent sources of nutrients including vitamin B 12 and the antioxidant lutein, which is important for healthy eyes as we age.
– Research on the effects of the 212 milligrams of cholesterol in a large egg has shown no association between eating one egg a day and heart disease for the healthy person. But remember to account for eggs in products-cakes, cookies, pasta, for example-if counting dietary cholesterol is important to your health.
– Omega-3 enhanced eggs contain substantially more heart-healthy DHA compared to regular eggs. These eggs come from hens fed a special diet.
– Organic and conventionally produced eggs are equally nutritious.

Food safety:
– Eggs eaten raw or undercooked may cause serious illness from salmonella contamination. Bacteria can exist inside an uncracked, uncooked whole egg. Avoid eating raw cookie dough or making ice cream or Caesar salad dressing with raw eggs. Fully cooking eggs destroys the bacteria.
– Cook eggs until the yolk and the whites are firm. Cook egg custards used in eggnog, homemade ice cream and quiches until thickened to 160°. Bake meringues at 350º for 15 minutes on the lower rack in the oven.
– Substitute pasteurized eggs found on the grocer’s refrigerated shelf in recipes requiring the use of raw eggs without further cooking. There has never been a food-borne illness associated with the use of pasteurized eggs.

Storing eggs:
– Store eggs in their original carton to prevent them from absorbing odors from other foods in the refrigerator.
– Avoid storing eggs in the door of the refrigerator. The air at the door is warmer.
– Leaving eggs unrefrigerated even for short periods of time diminishes their freshness.
– Eggs retain freshness up to approximately one month after purchase and can be safely used if they’ve been properly refrigerated even if the sell-by date expires during this time.
– Raw egg whites will keep one week in the refrigerator and 12 months in the freezer. Egg yolks will keep 3 days in the refrigerator and 12 months in the freezer. Eggs in their shell will crack if frozen whole, and bacteria can enter into the egg through the cracks in the shell. 
– You can keep a hardboiled egg in the refrigerator up to a week before using. It’s preferable to store them unpeeled for optimal freshness and taste.

Egg labels:
– Organic eggs come from cage-free hens that can roam freely outside. They cannot be given antibiotics and are fed organic grain. This is the only label which is backed by USDA standards and regulations.
– Cage free eggs come from hens that are not confined to cages but may not have access to the outdoors. Their environment and the eggs they produce are not audited by a third-party. 
– United Egg Producers Certified eggs verify that food and water is provided to its caged hens. This voluntary program applies to 80 percent of eggs produced industrially. 
– There is no consensus of a definition or enforced or regulated standards or regulations for the following terms: free range, natural, no pesticides or no antibiotics.