Why are carrots orange? For political reasons.

Earlier this week I wondered what makes carrots orange. Grass is green because it contains a light absorbing pigment called Chlorophyll, and certain leaves are dark red because they contain a different light absorbing pigment to absorb a different colour of light (wavelength) to chlorophyll. All pigments are present in chloroplasts, which is the site of photosynthesis, and this reaction converts light energy to sugars, which the plant will use as a source of energy.

There are also orange pigments, called carotenoids, which also absorb light energy. Why then, I wondered, do carrots need light absorbing pigments if they grow underground? When I googled this, I half expected the sort of answer that explains the origin of the colour orange, as does this article:

Why are Carrots Orange?What makes carrots orange? The plant pigment that gives carrots and other vegetables their vivid orange colour is beta-carotene. Fruits and Vegetables that are yellow/orange in colour contain beta-carotene and carrots are one of the vegetables richest in Beta-Carotene. Our bodies convert beta-carotene into Vitamin One carrot supplies enough beta-carotene to meet our daily requirement for Vitamin A.

Carrots are orange because they absorb certain wavelengths of light more efficiently than others. Beta-carotene is the main pigment and is mainly absorbs in the 400-500nm region of the visible spectrum with a peak absorption at about 450nm. Carotenoids are one of the most important groups of natural pigments. They cause the yellow/orange colours of many fruit and vegetables. Though beta-carotene is most abundant in carrots it is also found in pumpkins, apricots and nectarines. Dark green vegetables such as spinach and broccoli are another good source. In these the orange colour is masked by the green colour of chlorophyll. This can be seen in leaves; in autumn, when the leaves die, the chlorophyll breaks down, and the yellow/red colours of the more stable carotenoids can be seen.

http://www.carrotmuseum.co.uk/qna.html#a1

However, initially I did not get this answer at all. In fact, this is the first result that popped up on google:

Why Are Carrots Orange? It’s Political.

No, the image above does not show some collection of freshly genetically designed hypercarrots in various colors of the rainbow. This is the spectrum of colors carrots used to have – and in some regions of the world you can still find white, yellow, red and purple carrots. In most countries however, carrots tend to be orange nowadays. Why is that?

Allegedly they are orange for entirely political reasons: in the 17th century, Dutch growers are thought to have cultivated orange carrots as a tribute to William of Orange – who led the the struggle for Dutch independence – and the color stuck. A thousand years of yellow, white and purple carrot history, was wiped out in a generation.

Although some scholars doubt if orange carrots even existed prior to the 16th century, they now form the basis of most commercial cultivators around the world. Presumably crosses between Eastern (purple), Western (white, red) and perhaps wild carrots led to the formation of the orange rooted carrot sub species. Turkey is often cited as the original birthplace of the hybrids (or mutations) of the two groups.

Whatever the origins, the Long Orange Dutch carrot, first described in writing in 1721, is the forebear of the orange Horn carrot varieties so abundant nowadays. The Horn Carrot derives from the Netherlands town of Hoorn in the neighborhood of which it was presumably bred. All our modern, western carrots ultimately descend from these varieties. Hypernature avant la lettre.

https://www.nextnature.net/2009/08/why-are-carrots-orange-it-is-political

So that explains why carrots are orange, but neither of those answers explain why root vegetables need light absorbing pigments. The answer in fact is that they don’t need the pigments. As explained on Quora, carrots never used to have many pigments. However, many years ago humans decided to cultivate carrots and we selected those which were most orange. Thus, we selectively bred the orange trait into these vegetables, resulting in the oranges which we see today. Carrots are orange because of humans!

Scott Strough, former worked on land and at sea

Excellent question. In the case of carrots what happened is we took a trait that had a purpose of storing these biochemicals for use later and selected for even stronger use of this trait. Wild carrots (queen anne’s lace, Daucus carota ) does not have such strong storage of Beta-carotene as our crop cultivars of carrots. But it does store some for regrowth of the above ground plant. We are the reason for the increase. Here is a very good source to learn about the history of the carrot and why it looks like it does today.

A brief summary and timeline of the carrot.

The history of every vegetable is different. But the common thread is we selected and bred the cultivars to supply our needs.

https://www.quora.com/Why-do-some-vegetables-for-example-carrots-contain-light-absorbing-pigments-if-they-grow-underground

And for a more scientific answer:

Hal Dace, Plant Stress Biologist in Wageningen, The Netherlands

Did you know that carrots were not originally orange? They were purple, white, green, yellow, all sorts of colors – but not orange. You can see some of those heritage varieties in grocery stores again these days. The orange color we know is the product of selective breeding.

But back to your question: the question of why structures that are never normally seenmight have pigments is much more interesting than you might think at first glance.

I’ll start with a strange and unrelated-sounding question: Why is visible light visible? That is to say, why, given a whole electromagnetic spectrum from ultra-long-wave, low energy radio waves to super-high-energy cosmic rays, did we evolve to only see a narrow band from about 390 to 700nm? Why don’t we see x-rays, or microwaves? Even other creatures that can see other wavelengths only really stretch into the near parts of the ultraviolet and infrared ranges.

The answer relates to organic chemistry: That range of electromagnetic energy is the range of energy that can excite pi electrons: That is to say, in an organic molecule with alternating double- and single-bonds, the electrons that form those bonds can be moved to a higher energy state by visible light without ionizing and potentially creating harmful oxidation reactions. At lower energies, radiation (like radio waves) cannot excite the electrons in organic molecules. At higher energies, radiation strips electrons off molecules and causes biochemical havoc — which is how sunburn can result in cancer or at least premature aging.

What does this have to do with carrots? Well it happens that those same systems that organic chemists call conjugated double-bond systems can also form a kind of buffer in the cell against oxidative damage caused by, among other things, high light intensities. They allow a plant to balance the oxidative and reductive potentials in the cell, and so deal with lots of high-energy sunlight coming in without suffering fatal damage to cells. So if you are a plant, and you want to synthesize a compound to soak up damaging free radicals etc., then a compound with conjugated double bonds — and so a lot of pi electrons — will probably be very useful for you. And those compounds are often visible as pigments, because the same properties that make them visible also make them useful as antioxidants. And even in roots, a reservoir of antioxidants can serve to help protect the whole plant. (Also remember carrots were bred to overproduce beta-carotene because it looked nice. But you also find it in leaves, although you don’t notice it with all the chlorophyll present)

This is why we are advised to eat a diet rich in different-colored vegetables, because those colors correlate well with the presence of antioxidants that we should be consuming in our diet.

 https://www.quora.com/Why-do-some-vegetables-for-example-carrots-contain-light-absorbing-pigments-if-they-grow-underground/answer/Hal-Dace
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3 thoughts on “Why are carrots orange? For political reasons.

  1. The title of your piece is a little misleading when you go to quote that” Allegedly they are orange for entirely political reasons” – allegedly is not fact. There is no documentary evidence for this assertion. Some astute historian managed to install the myth that Dutch arboriculturist’s work on an unexpected mutation was developed especially to give thanks to King William I as a tribute to him leading the Dutch revolt against the Spanish to gain independence from Spain. There is no documentary evidence for this story!

    And then you quote “A thousand years of yellow, white and purple carrot history, was wiped out in a generation.” under a modern photo showing ALL the colours of carrots which are currently available. I think your readers should visit the World Carrot Museum for the definitive history of the carrot, in all its colours.

    Liked by 1 person

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