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Offline neilep

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Do some vegetable HAVE to be cooked ?
« on: 19/04/2007 02:26:40 »
Potato(e), Parsnip, Turnip, Yam, Pumpkin.....can these be eaten safely without cooking? albeit yucky ?

Are there any veg which MUST be cooked for human consumption ?

If so...why so ?








 

another_someone

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Do some vegetable HAVE to be cooked ?
« Reply #1 on: 19/04/2007 02:36:21 »
Uncooked potatoes can be toxic (they are the same family as deadly nightshade - although so too are tomatoes, and they can be eaten raw).
 

Offline neilep

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Do some vegetable HAVE to be cooked ?
« Reply #2 on: 19/04/2007 14:39:33 »
Thank you George.

Amazing that tomatoes and potatoes are from the same family !

The reason I asked the question was because I was wondering what the premise of a vegetable would be. Presumably to successfully aid in procreation of it's species. Now I gather veggies were eaten by animals with far hardier digestive tracts than us before we came along so somewhere someone must have decided to see what potatoes were like cooked and therefore more palatable for human consumption.

Clearly , the first potatoes (and potoato related veggies) evolved to be consumed by something else...or is the premise of some vegetable to be in fact not be eaten ?.....hmmmm...the potatoes themselves spring the shoots of new plants !!...hmm..I think I've just answered my own question or can a potato(e) plant be cultivated via a different mechanism ?
 

Offline WylieE

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Do some vegetable HAVE to be cooked ?
« Reply #3 on: 19/04/2007 15:08:00 »
There are many vegetables that it is highly advised to cook:

Most of these are not due to the problems of the vegetables themselves, but what grows on them.  For example, peanuts should only be eaten cooked due to the presence of Aflatoxin.  Aflatoxin is a compound produced by fungi that live on the peanuts (and corn, and wheat, and soybeans, and others).  It can lead to liver cancer. Cooking also helps with the removal of E.coli (a serious problem here recently).


Raw kidney beans (and some other beans) and Soybeans (although to a lesser extent) contain hemagglutinins which cause problems with red blood cells.  These enzymes are destroyed by heat treatment.  Red kidney beans have the highest concentration of these enzymes and eating just a few can cause a severe symptoms (vomiting, diarrhea).  Occasional eating of plants that contain lower levels of these (soybeans) is probably OK, but eating a lot can be a problem (this can be seen in cattle fed raw, untreated soybeans).

And then there are those that require cooking just for taste - brussel sprouts would be a great example of this (although some contend that they are toxic uncooked if you eat enough).  Of course, I don't know how people can stand to eat them even after they've been cooked.

The most toxic thing (plant-wise) that I know of that humans eat regularly as a staple food crop is cassava.  It is used as a major food crop in many countries because it is highly drought tolerant.  However, it contains high levels of cyanide and if not cooked properly can (and does) cause a lot of problems.

Of course there are many toxic plants, but we don't eat these because of that reason, so they are not technically vegetables- however, some of the plants we eat now have some very toxic wild relatives so it is amazing that we ever domesticated them- I mean who was the first person to eat a raw eggplant- gross!

Spell check does not seem to be working- so my apologies for misspellings.
Colleen
 

Offline neilep

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Do some vegetable HAVE to be cooked ?
« Reply #4 on: 19/04/2007 15:20:13 »
WOW !!..THANK YOU COLLEEN !!

Ewe know stuff !!..

Do you think the same applies to all nuts ?..or is Aflatoxin predominant across the wide variety of nuts. I notice you mention corn and soybeans so I expect the answer to be yes..yes ?

THANK YOU again for your wonderful post.

Hugs the Colleen !

LOL...Brussel Sprouts......huurrlllllllll !!...aren't they just dwarf cabbages ?

By the way...your spelling is perfick !!
 

Offline Karen W.

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Do some vegetable HAVE to be cooked ?
« Reply #5 on: 19/04/2007 15:57:15 »
Uncooked potatoes can be toxic (they are the same family as deadly nightshade - although so too are tomatoes, and they can be eaten raw).

I have spent my whole life eating sliced raw potatoes from the garden. You have to be careful and not eat the ones that were exposed to too much light as they get this greenish tint just under the peel. One should digard a potato like that as it can make you sick! I am not sure why, My parents were good gardeners and had massive gardens every year. We always dug the potatos and sorted any green ones and tossed them. The green ones were always the surface potatoes and had been more or less exposed to too much light. We stored 100 Lb bags of potatos in the dark under the shelves in the back barn for the whole year. They lasted us all year as we stored many many bags a year in the barn . We had a large family of seven to deed so it was routine.

 I love raw potaos peeled sliced and eaten.. they have the consistancy of raw turnips that I also love to eat raw..washed sliced and set into iccy cold water and served fresh like that. I hate cooked turnips..LOL Potatos I like both ways.. you also lay your potatoes in water too before serving. Most people do not like them raw as they have a very earthy flavor and are starchy also.. I like them as they are crunchy..LOL I have never been sick from them.. although my brother had a run in with raw green potatos and that was way different got pretty sick but avoided the green after that and was fine.. LOL
 

another_someone

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Do some vegetable HAVE to be cooked ?
« Reply #6 on: 19/04/2007 15:58:01 »
A tomato is a fruit, and so was intended to be eaten.

A potato is a root vegetable, and was never designed for eating.

How someone worked out that a cooked potato was more edible than a raw one, I don't know - maybe they found some potatoes after a forest fire, and thought these are quite nice, lets see if we can have our own mini forest fire with potatoes?
 

Offline Karen W.

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Do some vegetable HAVE to be cooked ?
« Reply #7 on: 19/04/2007 16:01:10 »
LOL.. I like them both ways.. LOL
 

another_someone

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Do some vegetable HAVE to be cooked ?
« Reply #8 on: 19/04/2007 16:30:32 »
http://www.answers.com/topic/solanine
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Solanine poisoning

Symptoms

Solanine poisoning is primarily displayed by gastrointestinal and neurological disorders. Symptoms include nausea, diarrhea, vomiting, stomach cramps, burning of the throat, heart arrhythmia, headache and dizziness. Hallucinations, loss of sensation, and paralysis, fever, jaundice, dilated pupils and hypothermia have been reported in more severe cases.

In large quantities, solanine poisoning can cause death. One study suggests that doses of 2 to 5 mg per kilogram of body weight can cause toxic symptoms, and doses of 3 to 6 mg per kilogram of body weight can be fatal.

Symptoms usually occur 8 to 12 hours after ingestion, but may occur as rapidly as 30 minutes after eating high-solanine foods.

Correlation with birth defects

Some studies show a correlation between the consumption of potatoes suffering from late-blight (which increases solanine and other glycoalkaloid levels) and the incidence of congenital spina bifida in humans. However other studies have shown no correlation between potato consumption and the incidence of birth defects. [1]

Solanine in potatoes
Solanine occurs naturally in all nightshades, including tomatoes, capsicum, tobacco and eggplant, as well as plants from other species. However the most ingested solanine is from the consumption of potatoes.

Potatoes naturally produce solanine and chaconine, a related glycoalkaloid, as a defense mechanism against insects, disease, and predators. Potato leaves and stems are naturally high in glycoalkaloids.

When potato tubers are exposed to light, they turn green and increase glycoalkaloid production. This is a natural defense to help prevent the uncovered tuber from being eaten. The green colour is from chlorophyll, and is itself harmless. However, it is an indication that increased level of solanine and chaconine may be present.

Some diseases, such as potato blight, can dramatically increase the levels of glycoalkaloids present in potatoes. This is believed to be a natural reaction of the plant in response to disease and damage.

Commercial varieties of potatoes are screened for solanine levels, and most have a solanine content of less than 0.2mg/g. However potatoes that have been exposed to light and started to green can show concentrations of 1mg/g or more. In these situations a single unpeeled potato can result in a dangerous dose.

Avoidance

Solanine and chaconine are present in potato shoots. In potato tubers 3080% of the solanine develops in and under the skin and thus may be removed by peeling and removing the eyes. This is advisable if the tubers show green, but is not a guarantee of safety. Potato greening strongly suggests solanine build-up although each process can occur without the other. A bitter taste in a potato may be a more reliable indicator of toxicity.

Deep-frying potatoes at 170 C (306 F) will effectively lower glycoalkaloid levels, but microwaving is only somewhat effective and boiling is not.

http://en.wikipedia.org/wiki/Potato
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Potatoes contain glycoalkaloids, toxic compounds, of which the most prevalent are solanine and chaconine. Cooking at high temperatures (over 170 C or 340 F) partly destroys these. The concentration of glycoalkaloid in wild potatoes suffices to produce toxic effects in humans. Glycoalkaloids occur in the greatest concentrations just underneath the skin of the tuber, and they increase with age and exposure to light. Glycoalkaloids may cause headaches, diarrhea, cramps and in severe cases coma and death; however, poisoning from potatoes occurs very rarely. Light exposure also causes greening, thus giving a visual clue as to areas of the tuber that may have become more toxic; however, this does not provide a definitive guide, as greening and glycoalkaloid accumulation can occur independently of each other. Some varieties of potato contain greater glycoalkaloid concentrations than others; breeders developing new varieties test for this, and sometimes have to discard an otherwise promising cultivar.

Breeders try to keep solanine levels below 0.2 mg/g (200 ppmw). However, when even these commercial varieties turn green, they can approach concentrations of solanine of 1 mg/g (1000 ppmw). Some studies suggest that 200 mg of solanine can constitute a dangerous dose. This dose would require eating 1 average-sized spoiled potato or 4 to 9 good potatoes (over 3 pounds or 1.4 kg) at one time. The National Toxicology Program suggests that the average American consumes at most 12.5 mg/person/day of solanine from potatoes. Dr. Douglas L. Holt, the State Extension Specialist for Food Safety at the University of Missouri - Columbia, notes that no reported cases of potato-source solanine poisoning have occurred in the U.S. in the last 50 years and most cases involved eating green potatoes or drinking potato-leaf tea.

Solanine is also found in other plants, in particular the deadly nightshade. This poison affects the nervous system causing weakness and confusion.
 

Offline Karen W.

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Do some vegetable HAVE to be cooked ?
« Reply #9 on: 19/04/2007 17:35:13 »
OOOH Georgie That scares me some.. Maybe it has not been a problem because I have avoided the green ones >>>> Yikes... Makes me worry.. Not like I eat them every day, but sometimes when cutting them or cleaning them fo a dinner , I slice some for myself to eat before they cook! ..I think I am relatively safe, but that information answers why not to eat green potatos in a very big way!! No wonder me brother got so sick!!!  YIKES!!!
 

Offline WylieE

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Do some vegetable HAVE to be cooked ?
« Reply #10 on: 19/04/2007 18:02:36 »
The good thing about MOST toxic compounds is that they taste bitter and awful to most people (yet another reason to avoid brussel sprouts).  This is the case for glycoalkaloids, so even if a potato doesn't look green, but tastes bitter (even after cooking) don't eat it.  However, you can't rely on this completely, some people can't taste the bitter compounds so well (and thus can stand to eat brussel sprouts).
So I agree with George, as much as you love it, don't eat raw potatoes- Also, the issues of bacteria and fungi that live on them add another reason to cook them first.
Still no spell check, sorry.
Colleen
 

Offline Karen W.

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Do some vegetable HAVE to be cooked ?
« Reply #11 on: 19/04/2007 18:15:42 »
That is weirdo thing about spell check are you sure, mine is working
« Last Edit: 19/04/2007 18:17:42 by Karen W. »
 

Offline Bored chemist

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Do some vegetable HAVE to be cooked ?
« Reply #12 on: 19/04/2007 19:52:54 »
I'm pretty sure that solanine and such like in spuds (and come to that, the completely different alkaloids in deadly nightshade) will survive cooking. You might get rid of some of them in the water if you boil them but that's not the reason for cooking them.
Even healthy "un green" potatoes contain these toxins (someone once calculated that a coffin full of potatoes would have enough to kill you) If they were broughtto the market now they would be banned as toxic.
 

Offline WylieE

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Do some vegetable HAVE to be cooked ?
« Reply #13 on: 19/04/2007 20:38:29 »
Right BC,

 It is mostly in peeling the potatoes that you get rid of the glycoalkaloids.  There are some studies that if you cook at high temperatures you can break these down.  There is a really old study showing that cooked potatoes, boiled or steamed have slightly lower levels  than raw potatoes(but they didn't show if this was statistically significant). But I would never eat a green potato- cooked or uncooked- you just can't get rid of them that well by cooking- I avoid eating potato chips with green on them, even a little bit.

Some glycoalkaloids are desirable, they add to the flavor (what little there is) of potatoes- it is just a matter of dose.  One potato with high levels (green) can be very bad news.  However, most potatoes just don't have that much.  Potato breeders work hard to keep the levels fairly low in "healthy" (aka "un-green") potatoes.  I think this is the same argument I have heard (although I can't find any papers now) for brussel sprouts- that if you eat enough of them. . . I don't even think it takes a coffin full. 

Funny, I think a lot of the things we eat / drink - cassava, coffee, potatoes, brussel sprouts, eggplant, fugu, sushi, would probably have a hard time passing the restrictions it takes for pharmaceuticals to get on the market.  Certainly this would be true for peanuts- with as many people as have allergies to them (and how severe the allergies can be). 
 

another_someone

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Do some vegetable HAVE to be cooked ?
« Reply #14 on: 19/04/2007 21:10:11 »
http://extoxnet.orst.edu/faqs/natural/goi.htm
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Food plants species in the Cruciferae (Brassicaceae) family contain substances called glucosinolates, which probably play a role in the plant's defenses against predators and fungal attack. When eaten by animals or humans, glucosinolates can inhibit thyroid gland functioning, causing enlargement and atrophy of the thyroid, or goiter.

Brassica species containing goitrogens include cabbage, broccoli, cauliflower, rutabaga, kohlrabi, and the oilseeds, rapeseed and canola. The enzymes required for production of goitrogens in the plant are destroyed by cooking. Goitrogens are also lost through leaching into cooking water.

Effects in Animals

Feeding rapeseed meal with high glucosinolate levels to animals and poultry induces enlarged thyroids, reduced circulating thyroid hormones, liver, kidney, and adrenal abnormalities, and poor growth and reproductive performance.

Effects in Humans

One study showed no ill effects when volunteers ingested 40 mg goitrin/day in Brussels sprouts over a 4-week period. Another study showed inhibition of iodine uptake after administration of 50-200 mg of goitrin. Studies in Great Britain estimated an average intake of 76 mg glucosinolate per person per day, with a range of up to 200 mg per day.  Whether or how much the consumption of Brassica vegetables contributes to ill health in humans is unknown. The cause of endemic goiter in certain geographic regions may be the result of the interaction between iodine deficiency and certain food components, such as glucosinolates.

Many nutritional studies have shown that dietary fruits and vegetables, including those in the Brassica group, have a protective effect against certain cancers. In animal studies, glucosinolates and their breakdown products have inhibited tumor formation, although this anti-carcinogenic effect depends on the study design, the type of cancer being studied, whether other dietary components are present, and the timing of the administration of the glucosinolate compound.

In summary, glucosinolates are known to be goitrogenic in animals, but their role in inducing goiter in humans is less clear. They can be anti-carcinogenic and cancer-promoting, depending on the species and circumstances of administration. In general, dietary vegetables, including Brassica vegetables, are beneficial in cancer prevention.
 

another_someone

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Do some vegetable HAVE to be cooked ?
« Reply #15 on: 19/04/2007 21:11:42 »
http://extoxnet.orst.edu/faqs/natural/pro.htm
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Protease inhibitors interfere with the action of trypsin and chymostrypsin, enzymes produced by the pancreas to break down ingested proteins. They are found to some extent in cereal grains (oats, barley, and maize), Brussels sprouts, onion, beetroot, wheat, finger millet, and peanuts. They have caused pancreatic hypertrophy in chicks and rats, but no ill effects have been observed in calves, pigs and dogs.

Raw soybeans have high levels of trypsin inhibitors. Soybean fractions high in trypsin inhibitors depressed the growth of rats, chicks, and mice. Cooking heat largely destroys the trypsin inhibitors in soybeans, but 5 to 20% of the original trypsin inhibitor activity may be retained in commercially available soybean food products. For example, while raw soy flour contains 52.1 TI (trypsin inhibitor activity) per gram of sample, toasted soy flour contains 3.2-7.9 TI per g.
 

Offline DrDick

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Do some vegetable HAVE to be cooked ?
« Reply #16 on: 20/04/2007 00:47:53 »
I've always loved raw potatoes, as long as they're salted.  I always have a bit or two when making mashed potatoes.  I never knew that the green ones were poisonous, but I did know that they tasted awful, so I stay away from them for that reason.

I also hope that baking gets rid of the poisons, since the potato skins are my favorite part.  I like to scoop out the white of the potato, slap some butter inside and eat them separately.

Dick
 

Offline WylieE

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Do some vegetable HAVE to be cooked ?
« Reply #17 on: 20/04/2007 14:11:14 »
Potato skins. . .
  Healthy potatoes (non-green, non-sprouting) have low levels of glycoalkaloids, even in the skin, they have been bred to reduce the levels, so eating them is probably not a problem.  Besides, most of the nutritional benefit of potatoes is in the skin (fiber, vitamins).  Like everything else, moderation is a good thing.  However, don't eat green skins or ones that taste bitter- cooking won't safely remove the glycoalkaloids.
Yay, spell check is back!  THANKS!
Colleen
 

Offline neilep

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Do some vegetable HAVE to be cooked ?
« Reply #18 on: 20/04/2007 14:23:05 »
THANK YOU all for your continued posts here.


RAW POTATOES !! ??...........YUKKKKKKKKK !!!!
 

Offline Karen W.

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Do some vegetable HAVE to be cooked ?
« Reply #19 on: 20/04/2007 15:38:57 »
HAve you tried one!! sliced washed etc. Has a nice earthy flavor.. They are nice.. LOL Maybe I like dirt too! LOL
 

Offline neilep

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Do some vegetable HAVE to be cooked ?
« Reply #20 on: 20/04/2007 16:28:06 »
HAve you tried one!! sliced washed etc. Has a nice earthy flavor.. They are nice.. LOL Maybe I like dirt too! LOL

I have to say I have indeed tried one !..YUK !!...too starchy with white starchy stuff !..eurrgrgrhh !!!
 

Offline Karen W.

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Do some vegetable HAVE to be cooked ?
« Reply #21 on: 20/04/2007 16:31:35 »
HEE HEE HEE!! Well AT least you tried it!! LOL Most people say Yuck without trying it! LOL I don't eat a ton  of them just a few slices when I am cutting etc. Not often but I do like them, it brings back good memories of me moms Garden!
 

Offline DrDick

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Do some vegetable HAVE to be cooked ?
« Reply #22 on: 20/04/2007 18:40:52 »
hold your nose and you can't tell the difference between apples and potatoes (well, maybe some).  Why do you think the French term for potato is "apple of the earth"?  Both are crunchy and white.  :)
 

Offline Batroost

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Do some vegetable HAVE to be cooked ?
« Reply #23 on: 20/04/2007 19:12:58 »
Ah yes, but in old english "apple" simply meant "fruit" - any fruit. So I'm guessing the French should probably be translated as "fruit of the earth"; which kind of makes more sense?
 

Offline _Stefan_

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Do some vegetable HAVE to be cooked ?
« Reply #24 on: 21/04/2007 09:33:50 »
My dad told me when I was little that in Greek potato is called 'geomillo' which translates to 'earth apple'. The modern Greek word for potato is 'patata' (hehe).
 

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Do some vegetable HAVE to be cooked ?
« Reply #24 on: 21/04/2007 09:33:50 »

 

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