Pasteurized eggs are heated to minimum required temperature (usually 130 to 140 degrees) for a specified time. This destroys Salmonella but does not cook the eggs.
In the plant, the eggs ride a conveyor belt into a hot, humid room. Workers load the egg trays onto an industrial dumbwaiter that gently lowers the eggs into what some call "the Jacuzzi." The eggs spend an hour moving through a tank of hot, bubbly water, which slowly raises the temperature of the eggs to kill bacteria. The water churns to prevent the eggs from cooking as they're heated.
After the bath, an egg cracked into a bare hand feels about as hot as a warm mug of coffee. The eggs are considered safe to eat, even if they don't reach 160 degrees — the temperature at which an egg is considered fully cooked.
The heat causes proteins to link together - a side effect that makes it more difficult to whip pasteurized egg whites into peaks.
Chickens that are free-range might get some bugs or some weeds in the yard. It affects the color of their yolk — it's much richer and darker. A lot of people who are used to supermarket eggs don't like them because they're too 'eggy.'
Pasteurized eggs put to test: They're safer, but do they taste and cook the same? Chicago Tribune, 2010.
A simple visual guide to eggs http://goo.gl/h8Gxt