How fresh are your eggs? The different parts of an egg are good indicators of just how fresh an egg is.
One indicator of egg freshness is the chalazae. The two chalazae appear white and stringy – they are safe to eat and disappear during the cooking process. As an egg ages the chalazae disappear, so thick chalaza are a sign of freshness.
The egg white (albumen) consists of two parts: the thick albumen surrounding the yolk and the thinner albumen that encompasses the thick albumen. As an egg ages, the thick albumen becomes thinner and more watery. Egg whites appear clear but may be cloudy due to the presence of carbon dioxide. As carbon dioxide escapes through the shell over time, the egg white becomes clear. Cloudy egg whites indicate very fresh eggs. Excess riboflavin gives a fresh egg white a green hue.
Yolk color comes from the types of grain in chicken feed. A lemon yellow yolk color reflects a wheat-based diet. An alfalfa or corn-based diet produces an orange-yellow yolk color. Over time, the yolk becomes flatter and breaks easily.
The color of the shell of an egg is determined by the breed of the hen. Shell color has no effect on the nutritional value of the egg itself.
Egg shells contain 90% calcium, 6% magnesium and 1% phosphorus.
Occasionally you may find a brown spot in your egg - do not panic and don't through the egg away. This is a meat spot and will not harm you if you eat it.
Meat spots are simply excess reproductive tissue released from a hen's ovary following the formation of a yolk.
They can range in size from 0.5 mm to 3 mm. They may appear maroon, tan, gray or white in color. They are hereditary and more common in older hens. Aging blood spots can be mistaken for meat spots, indicating an old egg.
Meat spots do not indicate that the egg is fertilized.
Blood spots are caused by a rupture of blood vessels in the yolk and occur in less than 1 percent of eggs.
Blood spots are red but turn brown with time, so a bright red spot indicates a fresh egg.
Like meat spots, blood spots are safe for consumption. If you prefer, you can remove the blood spot or the meat spot with a clean knife.
Other Freshness Indicators
An old egg will float when placed in a bowl of water.
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