What is the situation with the white yolk of the egg

Normally, the yolk of an egg is yellow, but for some reason, the yolk of an egg may turn white. This situation is quite common. It is not because the egg has gone bad, but because of some raw materials in the poultry chicken's usual feed. Different breeding methods in different places and different feeds used can lead to this phenomenon. For example, if chickens are frequently fed with cassava, this phenomenon may occur.

What is the white yolk of an egg?

Under normal circumstances, the yolks of poultry eggs, including those of chickens, ducks and birds, will range in color from yellow to orange or even red.

Studies have found that the color of egg yolk is mainly caused by oxygen-containing carotenoids, which include lutein, zeaxanthin, canthaxanthin (also called canthaxanthin, canthaxanthin), astaxanthin, cryptoxanthin, echinone, capsanthin, etc. Egg yolks generally contain one or several of the above carotenoids, which is why they appear "colored".

Carotenoids Causes

Because the types and quantities of feed eaten by egg-laying birds are different, the types and quantities of carotenoids deposited in the egg yolk are also different, resulting in color changes from yellow to orange and even to red. Based on the maximum absorption wavelengths of these carotenoids, lutein seen by the naked eye appears yellow, zeaxanthin appears orange to orange-red, astaxanthin appears pink to red (the color of cooked shrimp and crab), and cantharides and capsicum appear red.

Specific reasons

Therefore, different places adopt different feeding methods (such as free-range or caged) or feed different types of feed. Due to the different types and quantities of carotenoids in the feed consumed by birds, the types and quantities of carotenoids deposited in the egg yolks are also different, so the color will also be different. Generally speaking, if the content of carotenoids is more red, the red color will be darker; if the content of carotenoids is less or the type of carotenoids is yellowish, the color will be light yellow.

Someone once did an experiment in which they fed chickens with cassava instead of corn. Because cassava contained too little carotenoids, the yolks of the eggs laid by the chickens were almost white. This shows the extent to which the type of feed affects the color of the yolk.

In fact, poultry cannot synthesize carotenoids by themselves and can only obtain them by eating feed. So it may be related to the specific ingredients of the egg-laying chicken feed, and it should not have much impact.