When You Look at an Egg, What Comes to Mind?

"Mmm, tasty."

"Egg drop contest!"

"Foams, emulsions... endless culinary possibilities."

"What happens if I don't cook it all the way?"

We want to focus this blog entry on eggs! Here are a few facts (and theories) about eggs that we find noteworthy.

Nutritional Overview of 1 Large Egg:

Calories: 75 (60 calories from the yolk, 15 calories from the white)
Calories from fat: 45 (% Daily Value)
Fat: 5 grams 8%
Cholesterol: 425 mg 70%
Protein: 6 grams 12%
Vitamin A: 8%
Vitamin B12: 25%
Folacin: 13%
Phosphorus: 11%
Iron: 5%
Riboflavin: 19%

Eggs are highly nutritious!

Safety

The main safety concern with chicken eggs is contamination by the bacteria, Salmonella (the same bacteria of concern when cooking the meat of a chicken).

The shell of an egg provides excellent protection against bacteria entering from outside of the egg. As long as the egg shell is intact, the risk of contamination is very low. To minimize the chance even further, commercial eggs are quickly washed with a sanitizing solution right after they are laid.

A study by the USDA (Risk Analysis April 2002 22(2):203-18) showed that of the 69 billion eggs produced annually only 2.3 million are likely contaminated with salmonella, equivalent to just one in every 30,000 eggs. That means that if four people each eat 2 eggs a week over the course of their entire lifetimes, one of those four people would have a single run in with a contaminated egg, and if that egg was cooked properly, no illness would occur. That's a fairly low risk. (Note that this is not the same in other countries where salmonella cases from eggs are a major concern.)

Storage and Handling at Home
The most prudent approach is to refrigerate eggs, use them within two weeks, cook them thoroughly, and to never consume raw eggs. Although eggs can be kept safely in a home fridge for 4-5 weeks, over time the whites become runnier and the yolks flatter. Thus, fresh eggs are much easier to poach and to separate (white from yolk).

Store eggs in their original container in the coldest part of your fridge. Using the molded rack in the refrigerator door exposes eggs to warm air every time the fridge is opened. The carton also protects the eggs from absorbing any strong odors from other items in the fridge. (Their shells are strong but porous. In addition to gaining odors, eggs lose moisture through their shell. Every egg has a small air pocket inside against the large end of the shell. This airspace grows over time as the egg loses water. The air pocket in a very old egg will be so large that it will cause the egg to float in water. Floating eggs should be tossed.)

Storing eggs large-end up (the way they come in the carton) keeps the yolk centered and away from the air pocket at the large end of the egg.

Just like handling raw meat, be sure to clean anything that makes contact with raw eggs (hands, utensils, surfaces) before preparing other foods, especially those that will not be cooked.

Allergies

Allergies to eggs, especially in infants, are not uncommon. Luckily, if exposure is limited, about 50% of kids with allergies to eggs will grow out of their allergy by age 6. Interestingly, allergic reactions to egg whites are more common than reactions to yolks.

Fun Fact

The difference between brown eggs and white eggs is simply the color of the hen's feathers. Hens with white feathers will lay eggs with white shells; hens with reddish-brown feathers will lay brown eggs. There are no differences in taste or nutrition between white and brown eggs.

Sources:

* Wikipedia
* The Wellness Encyclopedia of Food and Nutrition - UC Berkeley