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Carotenoids in potatoes (white, yellow, or purple flesh)
Hello all, I was craving potatoes lately but I was unable to find any white flesh potatoes where I live. All of the potatoes grown and sold here are yellow flesh (I live in the Netherlands). Yellow flesh potatoes are high in carotenoids such as lutein, so I avoid those. I did found a webshop that offers purple-flesh potatoes. The purple color seems to be caused by Anthocyanin which is not a carotenoid but does have anti-oxidant effects. So it seems eating purple flesh potatoes are OK to eat, since their overall carotenoid content is low. The main carotenoid found in purple/red flesh potatoes is neoxanthin which is broken down during boiling/cooking. Most carotenoids are in fact destroyed/broken down during the boiling process, except lutein and beta carotene. See the study below. This means we can potentially eat foods containing carotenoids as long as they are cooked, and are not high in the carotenoids lutein and beta-carotene.
The study below says the yellow potatoes they tested where high in antheraxanthin, but other sources on the internet say lutein is a major carotenoid found in yellow flesh potatoes.
In summary:
White flesh potatoes: low in carotenoids, low in anthocyanins. OK to eat.
Purple/blue/red flesh potatoes: low in carotenoids, high in anthocyanins. Neoxanthin is the main carotenoid found but is broken down during boiling. OK to eat.
Yellow flesh potatoes: high in carotenoids, high in lutein which doesn't break down during boiling. AVOID.
Orange flesh potatoes: high in carotenoids, high beta-carotene which doesn't completely break down during boiling. AVOID.
Carotenoid profile and retention in yellow-, purple-, and red fleshed potatoes after thermal processing.
This research aimed to investigate the effect of thermal processing on carotenoid profile, quantity and stability in 22 colour-fleshed potato cultivars grown in the Czech Republic. The total of nine carotenoids was analysed by HPLC using a C30 column and PDA detection. The total carotenoid content for all cultivars ranged from 1.44 to 40.13 μg/g DM. Yellow cultivars showed a much higher average total carotenoid content (26.22 μg/g DM) when compared to red/purple-fleshed potatoes (5.69 μg/g DM). Yellow cultivars were dominated by antheraxanthin, whereas neoxanthin was the main carotenoid in red/purple cultivars. Thermal processing significantly impacted all potato cultivars. Boiling decreased the total carotenoids by 92% compared to baking (88%). Lutein was the most stable carotenoid against thermal processing (decreased by 24-43%) followed by β-carotene (decreased by 78-83%); other carotenoids were degraded nearly completely. Increased formation of (Z)-isomers by thermal processing has not been confirmed.
"The level of carotenoids determines whether the tuber flesh is white, yellow, or
orange, whereas the anthocyanin levels lead to red, purple or blue flesh color (Morris et al.
2008)"
"Lu et al. (2001) found evidence suggesting that selecting for greater yellow flesh
intensity will result in higher levels of carotenoids."
"Purple and red potatoes contain
the greatest amount of anthocyanins while carotenoids are largely found in yellow and red
potatoes, with small amounts present in white potatoes (Brown et al. 2004)."
"The color of fresh potato flesh is determined by varying contents of blue or red anthocyanin pigments or results from the accumulation of yellow and orange carotenoids (Brown et al. 2005)."
"Lutein, zeaxanthin, violaxanthin and neoxanthin are the major carotenoids present in potatoes whereas β-carotene is present in trace amounts (Haynes et al. 2011)"
Microsoft Word - 267485_supp_undefined_5DAA49CC-B669-11E3-A405-111C2E1BA5B1.docx (colostate.edu)
This spring I was buying potatoes to plant and they were marked wrong, I had purchased bags that said white potatoes, but found that some were actually white inside, while some were more yellow inside. It's not obvious until you cut them and compare side-by-side.
As an aside, we received two boxes of apples as a gift, two normal, everyday types. When cut and compared there is a major difference in flesh color. The outside is very much the same. I find it interesting that the whiter flesh apple is more delicate for winter keeping.
I have also found that COLORED potatoes are somewhat easier to grow than white. There are also potatoes that are only colored on the outside, with white interior. They often get served unpeeled to show off their color (oops). Perhaps this is a good mix of trying to keep the pests away without harming the humans (as long as they are served PEELED! which BTW is traditional).
Asian pears come in a thick brown wrapper, and have white interior. No one really eats those peels, and they are tough for bugs too! These are the most carefree of the fruits to grow (for me).
asian pear and red (peel) potato
The big, colorful seed catalogs are arriving, and it's fun to look through them with a notion of VA reduction in your mind.
This discussion makes me think of "the Potato Eaters" and how it was known that this diet led to tooth loss. (gum disease being a VA problem)
Quote from Arena on January 1, 2021, 10:55 amthanks for this!
@orion what is your opinion on this? I eat a lotta potatoes, and so do you
Hi @are, I only eat white potatoes, they are always available here, but maybe only 2 or 3 meals per week, rice with beans are still the top staple. I think the fiber in potatoes should help as a binder, but I would worry about the high beta-carotene varieties, as I doubt that boiling affects the VA content, probably makes it worse. Makes me think the beta carotene could cleave in boiling(not sure if heat does this though), then you have two retinals ready to oxidize to retinoic acid. Maybe this is why pasteurized carrot juice is very problematic. Always good to completely peel the potatoes too, hopefully the flesh contains less then skin and flesh close to the skin.
so all this time when I thought I was eating low vit-A I have actually been on high vit-A because my diet contains a lot of potatoes.
2021 has dissappointed me already.
I don't even know what white potatoes are supposed to look like. They're all yellow where I live.
Here in the UK Lady Balfour potatoes are a good variety. They are pale skined and white flesh. 
Due to gut issues potatoes are my main source of carbs. Most of the organic potatoes sold in the supermarket are Lady Balfour. When they are unavailable, other varieties sold are:
Valor: white flesh, not quite as white as Lady Balfour but the next best.
Electa: Light Yellow. for me these are acceptable but not ideal
Triplo: Light Yellow. Again for me acceptable but not ideal
Marfona: Yellow
Melody: Yellow
I try to avaid Marfona and Melody and start thinking about substituting oats temporarily if these are all I can get.
For the most part Lady B's are available. Some years there is a gap between stocks from the last season and the new crop being ready and the others are used to fill the gap.
These are the varieties I've come across. I made a list for my own use so I would know which to avoid. I haven't tried red skinned varieties since they tend not to be so popular here, especially organic grown.