(The Herald Post) – A recent study published in Nature Ecology & Evolution has shed light on the factors affecting eggshell coloration and durability, providing insights into the fascinating journey eggs undergo from the moment they are formed in the hen’s body to the moment they reach our kitchen table. These findings not only help us understand the natural diversity of egg colors but also offer practical tips on how to determine their freshness and preserve them safely.
Eggshell Color: A Mixture of Climate, Genetics, and Breeds
Researchers have discovered that birds living in colder climates and with open nests tend to have darker eggshells, which help maintain their internal temperature when exposed to sunlight. However, the color variations in eggs, such as the Australian brown eggs and the American white eggs, largely depend on the breeds of chickens used in commercial farms. Australia predominantly uses breeds like Hy-Line Brown, ISA Brown, and Hi-Sex Brown, which have brown feathers and lay brown eggs, while American farms mostly rely on Leghorn chickens with white feathers and white eggs.
Egg Formation: A Delicate and Intricate Process
The process of egg formation is both intricate and delicate. It begins with the yolk moving along the tubes within the hen’s body, where the egg white is added in the magnum area. Subsequently, the egg membrane is formed in the isthmus, followed by the eggshell calcification in the shell gland, which takes about 20 hours. The egg’s unique shape is crucial to its durability, allowing it to withstand pressure from all sides without breaking, an essential feature for the hen’s safety.
Preserving and Testing Eggs: Debunking Myths and Safe Practices
Refrigerated eggs can last for 3 to 5 weeks, and the most reliable way to test their freshness is by cracking them open and checking their appearance and smell. While there are numerous myths surrounding egg preservation methods, such as water glass, it is crucial to avoid these practices as they can lead to bacterial growth and, in some cases, cause botulism due to the pickling lime used.