Poached, deviled, fried, omelet, hard-boiled or par-boiled, cook it the way you like because an egg never fails to transform into a fantastic meal on your plate. Eggs form an essential part of our dietary preferences, both egg white and egg yolk boast of health promoting properties. Egg yolks, shunned by some for fear of being ‘ fattening’, are in fact an excellent source of protein. They contain vitamin D which is necessary for bones and teeth and other essential nutrients that help balance blood sugar levels, protect against heart diseases, and support the healthy function of nerves and the brain. But have you noticed how the shade of the yolk ranges from dark yellow to bright and sometimes terribly pale yellow? Have you wondered what this colour tells you about the quality of the egg?
The colour of an egg yolk can not only indicate freshness, it may also tell about the nutritive value of the egg. Interestingly, the different colours of the yolk may also depend on the type of food a hen may have been fed with. That’s right! Basically, the intensity of the yellow colour predominantly depends on the natural yellow pigments, known as xanthophylls, which are produced by animals, in this case by hens, which are then deposited in the yolks.
It is also believed that the colour of the yolk also points to the nutritional value of the egg. According to Mrs. Khyati Rupani, Founder and Nutritionist at balancenutrition.in, “A dark yellow yolk is an indication of a nutritious and balanced diet fed to the chicken rich in xanthophyll, omega-3 fatty acids and meats.”
Typically, an orange yolk contains more vitamin A and beta carotene. They become orange for the same reason that carrots, also high in beta carotene, are orange. This color change and improved vitamin content is directly related to the quality of food the hen consumes.
As a matter of fact, the shell of the egg also determines the exposure it has got. Although shell colour is mainly determined by genetics, the effect of strong sun and high temperatures on the hens can produce a fading effect on the shells. Too much sun affects the surface pigmentation, thereby making them look pale. A bright white shade is an indication that the egg is fresh and not stored for a number of days.
Basically, the colour of the egg yolk does not tell if the egg is fresh or not. The colour of the yolk completely depends on the diet a hen has been given, a healthy hen will produce eggs that have a brighter egg yolk.
Source : http://food.ndtv.com