Egg yolk coloring experiment
How do you consider the color of egg yolk?
The color of egg yolk sold by merchants has many kinds from light-colored (looking white) to dark-colored (closing to red). Different people have different opinions. Some people prefer dark colors; while others prefer light colors. As a consumer, which kind do you prefer? According to my company’s investigation, most of the consumers consider that the darker the color of egg yolk is, the more delicious it is and the higher the nutrition value is. However, is that true? What is your opinion?
Generally speaking, people in European and American countries prefer light-colored egg yolk. However in Japan, dark-colored egg yolk is more popular. In America, the egg yolk used in experiment belongs to light-colored egg yolk.
Does the different color of egg yolk have deeper implications, such as nutrition value, taste and so on? How does it result in the differences of color of egg yolk? My company keeps thinking in practice, and hope that the questions above can be solved through this experiment.
We must know little about the method of adding pigment to change the color of egg yolk when raising poultry. So let’s prove the method by experiment. First, you should prepare for work. Red pigment and black pigment are prepared to add. The output of eggs are collected after adding edible food color feed, and the changes of color of egg yolk are observed after boiled eggs. Pigment used in this experiment is powdered pigment. Red pigment is “paprika pigment”, while black pigment is “Sudan black B pigment”. Incidentally, Sudan black B pigment is not food coloring, but staining pigment used in the experiment.
Shape of raw eggs
Comparisons of color of egg shell
The second line belongs to eggs adding black pigment.
The leftmost is the first day of egg after adding pigment, while the rightmost is the fifth day of egg after adding pigment.
No comparison experiment on squid ink black pigment is carried out this time. But our company has carried out this experiment before; finding out that egg yolk is not colored. By comparing the differences between Sudan black B pigment and squid ink black pigment, we can see that Sudan black B pigment is fat-soluble pigment, and that squid ink black pigment is water-soluble pigment. Water-soluble pigment is excreted from the body. It does not remain in the chicken body, so it does not change the color of egg yolk. Although there is no picture, the chicken after raising Sudan black B pigment feed has changed into black completely. It is confirmed from the result of experiment 2 that pigment inside the chicken’s body will influence color of egg yolk. It is also confirmed that from the changes of color of egg shell that pigment inside the chicken body will not only influence color of egg yolk, but also make the color of egg shell dark.
So, how does the egg inside chicken’s body produce? Egg maturation needs about 8 to 9 days. First, the egg yolk part is formed. Then protein will wrap egg yolk. Next egg shell membrane and egg shell has grown up, which is excreted from the chicken’s body. It is observed from the experiment that egg yolk forms from the outside to the inside. The complete coloring of egg yolk needs 10 days.