What makes egg yolks darker

Turns out that besides being a coveted color, orange yolks can be an indication of a well balanced and highly nutritious diet. A few things factor into the making of an orange yolk: xanthophylls, omega-3 fatty acids, and meats.

The chemicals responsible for yolk coloring were first documented in in the Journal of Biological Chemistry. He determined that orange yolks were produced by a class of carotenoids called xanthophylls, and over years later, this conclusion is still widely accepted.

Carotenoids are natural plant pigments found in many fruits and vegetables. The carotenoids that cause deeper yolk coloring are xanthophylls, which are more readily absorbed in the yolks.

Lutein is one such xanthophyll, and a lot of lutein means a lot more orange. Xanthophylls are found in dark leafy greens like spinach, kale, and collards, as well as in zucchini, broccoli, and brussels sprouts. I know it seems weird that a carotenoid that turns egg yolks orange is found in green vegetables, but stay with me here.

Omega-3 fatty acids are highly concentrated in oily fish especially cold-water fish like salmon, tuna, and mackerel , shellfish, algae, tofu, and high-fat plant foods like brusssels sprouts, navy beans, and avocados. Chickens are omnivores by nature and their healthiest diets include meats, such as mealworms, beetles , grasshoppers, grubs, and whatever creepy-crawly they can pull out of the ground.

You see, color alone has very little to do with the nutritional content of an egg yolk. Yolk color depends almost entirely on the pigments found in the food that chickens eat. A diet of wheat or barley results in eggs with lighter-colored yolks, and a colorless diet such as white corn produces nearly white yolks. It could mean the egg producer is only giving the hens minimal access to the outdoors, like a single door out to a patch of grass. Chickens whose diets are rich in leafy greens, flowers, seeds, weeds, and meat lay eggs with naturally darker yolks.

The xanthophylls, omega-3 fatty acids, vitamins, and minerals in these food sources are then passed on to their eggs and concentrated in their yolks.

Research has shown that of all the nutrition found in eggs, most of it is found in egg yolks , including fat-soluble vitamins like D, E, K, and A none of which you get from egg whites , essential fatty acids like DHA and ALA, and other nutrients like calcium, iron, magnesium, zinc, choline, and B vitamins. According to Mother Earth News , which conducted its own egg analysis, and a more recent Pennsylvania State University study , pastured eggs where hens are given free range with ample access to greens and bugs contain higher levels of vitamins A, D, and E, more beta-carotene, and more omega-3s than eggs from caged chickens fed primarily grain.

All this means is that a pastured egg ideally from your own yard is healthier for you. They like to scratch through leaf piles and layers of mulch where grubs and earwigs often hide. Pastures or backyards full of rich grasses, ground covers, and cover crops are a wonderland for your flock, giving them plenty of opportunity for forage and exercise.

The darker the green the better, so I often fix them a feast of edible amaranth one of my favorite summer greens , kale, mustard greens, broccoli leaves , or whatever I happen to have growing in my garden. Rather than pulling all those vitamin rich! Chickens are very handy helpers at the end of the season when most of your plants have bolted and become aphid-ridden.

Let the chickens clean up those plants before you toss them into the compost. Except the bugs, that is…. If you have an open compost pile, chickens do good work of turning over yard debris and kitchen scraps as they scratch and peck for grubs and worms. Black soldier fly larvae, which are commonly found in decaying organic matter, have even more protein than mealworms and are naturally high in calcium.

The No-Waste Vegetable Cookbook is my latest book. Garden Betty is where I write about modern homesteading, farm-to-table cooking, and outdoor adventuring — all that encompass a life well-lived outdoors. After all, the secret to a good life is Read more ». I was skeptical reading your write up. Because I thought, here we go again, another blog that will associate orange yolks to organic feeding.

But as I read through the blog, It is backed up by research. As an animal nutritionist, I loved the blog. It is true that whatever the chickens eat will affect the color of the yolk. Thank you for explaining it in a way that everyone can understand. We saw this colour change when we got our first hens — 3 Isa Brown hens — and they were free range in our back yard that had plenty of insects, grubs and lush green grass and weeds.

My son returned home from visiting his father and the first time he went to use the freshly laid eggs he called me over and asked if our 2 day old eggs were rotten because of their dark golden orange colour. There is an amazing difference in the colour of hens on a correct natural diet and those that are not. We live in Australia and are currently in a drought and the lack of growth of everything green is showing up in our paler coloured eggs.

Praying for rain to replenish the earth and put out the fires over here. My best to you in Australia! Doing a rain dance for you and hope for the return of greener pastures soon! When I went to Australia all the eggs I bought from stores or restaurants all had bright orange Yolk. I did not see yellow once. Our egg industry obviously cuts a lot of corners. Nice to know what goes into your free-range egg! Actually it has been scientifically proven that most darker egg yolk has much more nutritional benefits.

Including much more cholesterol which has been scientifically proven to be very necessary for the human brain and other health benefits! Please note that it has been scientifically proven that when humans eat food that is high in cholesterol it has no effect on blood cholesterol levels! Hydrogenated or partially hydrogenated oils are used in many food products as a preservative and it is killing people!

The best thing that came out of the Obama administration was to attempt to force the FDA to get that stuff out of our foods. Please get hydrogenated and partially-hydrogenated oils and other food products that contain them out of your diet! Most breads, cake mixes, and ready to eat products sold in a supermarket has it as an ingredient. It has been scientifically proven to cause hardening of the arteries which is the leading cause of high blood pressure.

Any hen can lay such an egg if fed nutritious food. Hens raised on a vegetarian diet lay eggs with light coloured yolks. Such hens are fed foods like corn, alfalfa, and beans, all of which are rich in a pigment called xanthophylls, which is responsible for giving plants and animals the colour yellow, hence influencing the colour of the yolk.

This is the most common yolk colour. Hens that are fed a diet that comprises of foods low in xanthophylls, such as wheat , white cornmeal, or barley lay eggs with pale yellow, or in some cases even white yolks.

Hens fed more nutritious food will not only lay eggs with a darker coloured yolk, but the eggs will also be bigger in size. When it comes to nutrition, eggs with a darker yolk have been shown to contain higher levels of vitamins A and C, and omega fatty acids. However, although the macronutrient composition is the same for eggs with different yolk colours, we have to also take into account the size of the egg.

A larger egg will certainly contain more nutrients because of the higher albumin and yolk concentration. Rather, the colour of the egg shell depends on the breed and colour of the hen. Hens with white feathers lay white-shelled eggs, and hens with red feathers lay brown-shelled eggs.

But why are brown-shelled eggs more expensive? The breeds that lay eggs with a brown shell are much larger, and are therefore fed food with more nutrition and in higher quantity. So the cost of raising these hens is pricier.

There are many diets that are given to chickens in order to raise them. What the hens eat is what they lay. More nutritious the diet, darker is the colour of the yolk. At the end of the day, the way you prepare the egg will make all the difference.

So making a delicious omelette with a pale yellow egg yolk might get lauded more than making a disastrous omelette with a dark orange yolk. A weekly guide to the biggest developments in health, medicine and wellbeing delivered to your inbox. Thank you for subscribing! Your subscription is confirmed for news related to biggest developments in health, medicine and wellbeing. Back to Top. Select a City Close. Your current city: Mumbai Mumbai search close.

All Bombay Times print stories are available on. We serve personalized stories based on the selected city OK. Go to TOI. The Times of India. Are darker egg yolks better? Some people think that eggs with darker yolks have a stronger flavour. Are orange yolks better than yellow? No yolk colour is better than any other and is no indication of nutritional content.

What colour are bad eggs? Yolk colour does not change as eggs age. Dark yolks are perfectly safe to eat. Whether raw or cooked, your nose will be able to tell you if your eggs are still good or not. What colour should fresh egg yolks be?