Generally, we are used to seeing two colored eggs, or brown or white. However, sometimes we can get surprises with other colors, as striking as the greenish blue. Find blue eggs it can impact and lead us to think that they are not in good condition. However, it is simply a mutation in a chilean chicken breed, which led to the accumulation in the shell of large amounts of biliverdina greenish pigment that is obtained from hemoglobin.
For years it has been thought that these eggs could be more or less healthy than the brown or white ones of a lifetime. It went from saying that they barely had cholesterol to bet because they actually had much more. In this way, his fame was changing as established ideas changed. Today we know that, in reality, their nutritional value is not very different, apart from the fact that they have a little more proteins and a larger amount of carotenoids, which give it a more golden yolk. But the difference is very small.
Instead, they do have an advantage and a disadvantage that do make blue egg laying hens unique. On the one hand, these hens tend to lay fewer eggs. While others lay one daily, these often leave one or several days between one egg and another. But on the other hand, its shell is thicker. This keeps them safer from changes in humidity, so they stay fresh longer.
The virus that ‘gave’ us blue eggs
Studies conducted on blue eggs indicate that they are due to a mutation that occurred in chilean chickens hundreds of years ago. And, when it appears, a retrovirus is to blame for the mutation.
These are viruses that have their genetic information contained in RNA molecules. When they infect our cells, they have the ability to convert that RNA into DNA, which is the molecule in which we contain our information. Thus, they can be inserted into our genetic material, producing mutations. After all, we already know that our genome it is a kind of book made up of letters that contain the information that makes us who we are. If new letters suddenly get in the way, all sorts of changes can occur, depending on where the insert was generated.
Talking about retroviruses can remind us of the HIV, but not all are so dangerous. In fact, many of our characters come from mutations produced in our ancestors by the insertion of these viruses in their genome. And it is that, if it happens that this change of letters is positive, that new characteristic can end up being selected and endure over time. Sometimes it does so even when it is negative, since it is believed that some diseases are due precisely to the presence of viruses that were inserted into our genome. But that is another question.
Returning to the subject of blue eggs, a mutation caused by retroviruses accidentally produced the synthesis of the protein that promotes that blue egg. biliverdin accumulation in the eggs. This must have caught the attention of chicken farmers, who decided interbreed mutated hensuntil obtaining the breed that today is known as Araucana hen.
there is nothing to fear
Now, there is something that we must be very clear about. If the eggs are blue today, it has been due to the selection of that mutation. But already there is no trace of the virus. Blue eggs do not have any viruses inside them and neither do the hens that lay them.
Simply, it is about one more quirk, which has nothing to do with the state of the egg. So, in short, yes, it is safe to eat blue eggs. They are not spoiled and, in fact, may keep them fresh longer. Therefore, if you have had one in a dozen, try to leave it for the end and consume it last. But eat it without fear.