The Color of the Yolk Does Matter and Farmers Know How to Tamper with It. This Is Nothing but Egg‑Manipulation!

You must have noticed while breaking eggs that the yolk might come in a number of shades or even colors. Are eggs with intensive yellow yolk healthier?

The color of the yolk is affected by carotenoids, natural coloring agents present in plants, and beta-carotene, though in smaller extend. Chickens' diet has impact on the levels of the agents in their bodies.

•Free range hens are fed with grain and have access to green grass, other plants and small invertebrates. That is why their yolk is rich in karotenoids and the yolk color is intensive yellow. In the winter, due to limited sun exposure, they become slightly lighter.

•The eggs from cage hens or barn-laid are paler or medium-yellow. These birds are fed with corn flour, wheat and barley. They don’t have access to plants growing outside.

Chicken farms often play mischievous tricks and try to 'upgrade' the yolk color by means of coloring agents. The European Union has allowed eight coloring agents (natural and synthetic) which could be added to forage. Organic farming allows the use of organic agents only.

By applying synthetic agents (for example canthaxanthin) or natural ones (like capsanthin, lutein or zeaxanthin) you can tamper with the yolk color making it more attractive for customers who prefer eggs with intensively yellow yolk. This trick is also possible by adding the following plants:

• tomatoes, red pepper, carrot and marigold extract – they make the yolk more orange,

• dried nettle, soya, yellow corn flour and kale – they make the yolk intensively yellow

• white corn flour, wheat and barley – they decrease the intensity of the yolk's yellow color.

It was also proven that the eggs with intensively yellow yolk do not contain more nutrients than the paler ones. And they do not contain more vitamin A, either.