Solanine Quest

[postman]

There MUST be a way to effectively lower the glycoalkaloid content in potatoes to the point where it's not even noticable. Potato is such a perfect food except for the glycoalkaloids, there must be a way to solve this problem. Peeling potatoes decreases solanine by about 30-70% but that is not nearly enough if you're sensitive to this poison.

The current leads I'm going to look at:
1. Deep frying at high heat, at least 190 degrees celcius
2. Canned potatoes
3. Extracting solanine with acid solutions

If you have any thoughts or experiences about effectively killing the solanine content in these precious tubers please share it in this thread.

 

[dwide]

Anecdotally, I've always preferred roasted/fried potatoes over mashed -- even when the amounts of fat in each are equal. I've always attributed it to a texture thing, but it could very well be a solanine thing. I actually find boiled then mashed potatoes kinda gross.

Re: canned potatoes, I don't think they're cooked well enough. And then there's the whole resistant starch thing. I do poorly on canned potatoes.

 

[postman]

According to this study, all of the solanine should be destroyed by deep frying potatoes at 200 degrees celcius for 30 minutes. I've never deep fried anything before. Is it possible to deep fry potatoes for 30 minutes or would they burn? I guess it is possible that it works faster than that and that the researches just didn't measure it until 30 minutes of frying. See attached image.

https://www.tandfonline.com/doi/full/10.1080/10942912.2018.1509346

Anecdotally, I've always preferred roasted/fried potatoes over mashed -- even when the amounts of fat in each are equal. I've always attributed it to a texture thing, but it could very well be a solanine thing. I actually find boiled then mashed potatoes kinda gross.

Re: canned potatoes, I don't think they're cooked well enough. And then there's the whole resistant starch thing. I do poorly on canned potatoes.

That is interesting. From what I have seen so far it seems like regular frying will reduce the solanine content by about 50%. Although some studies say it destroys up to even 97%, and in a short amount of time too, just a minute. However according the study I cited in this post it seems like you need a very high frying temperature to really annihilate the solanine content. McDonalds fries their fries at about 170 degrees if I remember correctly, so solanine content it would still be about 50% lower than in a regular peeled boiled potato. Assuming they switch out their frying oil with some regularity, some people think the oil gets saturated with solanine and that some of it can then get reabsorbed into the next batch of fries.

About the canned potatoes, even if they're not cooked enough you could just cook them more yourself. What I'm curious about is if the process of canning and storing the potatoes like that breaks down the solanine somehow, which some studies have alluded to. I haven't looked to much into it yet though, it might just be some kind of analytical error, comparing dried canned food to food with moisture etc.

 

[dwide]

How do you know you need to destroy all the solanine though? Wouldn't peeling then frying be enough? If peeling reduces say 50%, then frying 50% more, that's a 75% total reduction.

I'd think that pan frying with just a small amount of oil, vs deep frying, would get the temperatures pretty hot. Less oil to buffer the heat between the pan and the flame. It can get pretty messy though. (Which is why I prefer roasting.)

Another thought: Air fryer?

For reference, I made roasted potatoes tonight. Cut into french fry shapes, took about 45 minutes at 400F to get to my preferred doneness. Actually overcooked them a bit, some smaller pieces were pretty burned. I would guess that those smaller were probably pretty close to 400F in temp. If I remember I'll stick an instant read thermometer in one next time I cook them.

I think my main issue with canned potatoes is resistant starch, and I don't think extra cooking removes it.

 

[InChristAlone]

I do best with very processed potatoes freshly cooked. No cooling and reheating.

 

[dwide]

I do best with very processed potatoes freshly cooked. No cooling and reheating.

Same. Kind of a pain in the **** but oh well.

 

[dwide]

I made potatoes again tonight. Roasted at 400F for 50 minutes. An instant read thermometer measured the insides at about 205F (96C). I tested a few pieces and it was consistent. I thought it would've been higher. (The outer crust was probably a lot hotter but I didn't measure it.)

 

[postman]

How do you know you need to destroy all the solanine though? Wouldn't peeling then frying be enough? If peeling reduces say 50%, then frying 50% more, that's a 75% total reduction.

I'd think that pan frying with just a small amount of oil, vs deep frying, would get the temperatures pretty hot. Less oil to buffer the heat between the pan and the flame. It can get pretty messy though. (Which is why I prefer roasting.)

Another thought: Air fryer?

For reference, I made roasted potatoes tonight. Cut into french fry shapes, took about 45 minutes at 400F to get to my preferred doneness. Actually overcooked them a bit, some smaller pieces were pretty burned. I would guess that those smaller were probably pretty close to 400F in temp. If I remember I'll stick an instant read thermometer in one next time I cook them.

I think my main issue with canned potatoes is resistant starch, and I don't think extra cooking removes it.

 

[postman]

So this is the study from which the claim that deep-frying potatoes only reduces the solanine content by about 30-40% stems from. It's an old Japenese study from 1989.

Effect of Cooking on the Contents of α-Chaconine and α-Solanine in Potatoes
Sci-Hub | Effect of Cooking on the Contents of α-Chaconine and α-Solanine in Potatoes. Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi), 31(1), 67–73_1 | 10.3358/shokueishi.31.67

I don't understand what's going on in this study. It doesn't seem to be properly translated. I would appreciate if someone who is experienced with reading studies took a look at this, or someone who can read Japanese.

They did four different tests for solanine content. Raw potato, boiled potato. microwaved potato, and deep-fried potato. And there are 4 different tables, and then there are three different figures, one for the solanine content of the boiled potato over time, microwaved potato over time, and for some reason, oven-baked potato over time? Where is this oven baked chart coming from? It's not mentioned anywhere else in the article. This supposedly oven-baked potato was also heated to the same temperatures that their deep-fried potato were. Is this a misprint, mistranslation, or is it maybe described only in the Japanese section of the paper? That chart, Fig. 3, looks very much like the deep-frying charts from other studies, and very much unlike oven-baked potato charts from other studies. Taken at face value this study says the opposite of every other study, it says that oven baking will remove all the solanine, and deep-frying is useless in comparison.

How do you know you need to destroy all the solanine though? Wouldn't peeling then frying be enough? If peeling reduces say 50%, then frying 50% more, that's a 75% total reduction.

I'd think that pan frying with just a small amount of oil, vs deep frying, would get the temperatures pretty hot. Less oil to buffer the heat between the pan and the flame. It can get pretty messy though. (Which is why I prefer roasting.)

Another thought: Air fryer?

For reference, I made roasted potatoes tonight. Cut into french fry shapes, took about 45 minutes at 400F to get to my preferred doneness. Actually overcooked them a bit, some smaller pieces were pretty burned. I would guess that those smaller were probably pretty close to 400F in temp. If I remember I'll stick an instant read thermometer in one next time I cook them.

I think my main issue with canned potatoes is resistant starch, and I don't think extra cooking removes it.

I made potatoes again tonight. Roasted at 400F for 50 minutes. An instant read thermometer measured the insides at about 205F (96C). I tested a few pieces and it was consistent. I thought it would've been higher. (The outer crust was probably a lot hotter but I didn't measure it.)

I'm very sensitive to the solanine so I need to reduce it to almost nothing. It's not just about the temperature, when you deep fry the potato much of the solanine actually seeps out into the oil. I don't think roasting it in the oven will do much, most of the studies say it barely does anything to reduce the solanine.

I do best with very processed potatoes freshly cooked. No cooling and reheating.

That's probably a fiber and resistant starch issue rather than something related to the alkaloids.

 

[dwide]

Ever tried japanese sweet potatoes? They have a whitish-yellow flesh. Super tasty too. Unsure of the carotenoid content, might still be too high.

 

[postman]

Ever tried japanese sweet potatoes? They have a whitish-yellow flesh. Super tasty too. Unsure of the carotenoid content, might still be too high.

That's a good idea. Never tried one, never seen one iny life in fact. They are very rare here. I'll see if I can find one.

 

[postman]

Ever tried japanese sweet potatoes? They have a whitish-yellow flesh. Super tasty too. Unsure of the carotenoid content, might still be too high.

Unfortunately it looks like they are still quite high in carotenoids: https://www.researchgate.net/public...cal_sweet_potato_ipomoea_batatas_flesh_tubers

 

[pauljacob]

How about microwaving. I nuke my potatoes as a fast cooking method. According to Wikipedia, microwaving reduces Solanine by 15%.

Solanine - Wikipedia

 

[Literally]

According to an article at the Weston A. Price foundation and also Paul Jaminet's book, the great quantity of glycoalkaloids in potatoes are near the skin. This is because bugs must eat through the outer parts first. So by leaving, say 1/2" or more of potato near the skin you are probably avoiding most of them. Also, keep the out of the light in storage and avoid bruising them, as I believe both factors massively increase the level of toxin. Unfortunately many grocery stores really screw this up before you get to them.

The WAPF source also recommends just discarding any potato that shows visible green near the skin when cut, as well as any potato that has sprouted.

 

[pauljacob]

According to an article at the Weston A. Price foundation and also Paul Jaminet's book, the great quantity of glycoalkaloids in potatoes are near the skin. This is because bugs must eat through the outer parts first. So by leaving, say 1/2" or more of potato near the skin you are probably avoiding most of them. Also, keep the out of the light in storage and avoid bruising them, as I believe both factors massively increase the level of toxin. Unfortunately many grocery stores really screw this up before you get to them.

The WAPF source also recommends just discarding any potato that shows visible green near the skin when cut, as well as any potato that has sprouted.

@Literally, thank you. I usually liberally peal off the outer layer, so I was doing it right. I will start storing potatoes out of direct light from now on.

 

[Cirion]

I seem to do fine with potatoes by peeling them and boiling for a long time - until they're very soft. Slow cooking is probably another pretty valid option.

 

[Literally]

@Cirion I agree, and it seems like our ancestors would have been more likely to cook all kinds of things for a long time, in hot water.

 

[dwide]

When I buy potatoes, I usually dig through to get a bag underneath the top bags. The top bags have a tendency to have more green potatoes, because it develops as a response to light exposure.

It's dumb that grocery stores keep their potatoes out in light, but I guess they don't really have another option.

 

[InChristAlone]

Yeah I try to dig down and grab the bag that's not on top otherwise they start sprouting within a week.

 

[postman]

KR20010037020A - The method for removing solanine in potato and method for processing potato using it - Google Patents

Groundbreaking: How to Easily Remove Nightshade Toxins From Potato Starch