Cassava Poisoning

[David006]

Guys : Maybe I am Paranoid but just been google.. ing Cassava (yuka) and there are two types... one sweet one bitter. ( bitter being used for ethanol so they say)

The bitter one being a high cyonegenic i.e. it can produce cyanide in the ol bod if ingested without adequate/correct preparation and you die! (Seems sweet ones make great pancakes though).

Question is how can one tell the different plants.. no luck on google..anyone know which one they are planting.

rgds

david

[Maizefarmer]

All Cassava types have the potential to be toxic.

[bina]

the thai know which is which when they plant. frankly, mostly raise the nastier type for the cassava chemical factories. the sweet kind seems to be grown as a kitchen garden plant, and not so much as a money crop, at least in my husband's village in forat.; but all cassava of the stringent kind have to be treated before being eaten: rinsed, soaked, pre cooked... sorry cant remember. but there is tons of info on cassava.

bina

israel

[sinbin]

Please excuse my ignorance but I've just read the above and I'm somewhat perplexed. When 'cassava' is harvested the stems and leaves are then ploughed into the soil. If 'cassava' is poisonous, then that means that all 'cassava' grown land is then toxic ? So anyone building on, previous, 'cassava', planted land is building on contaminated land. If the toxin is only in the root then leaving any unharvested tubers in the soil still contaminates the land. Right or wrong ?

Edited October 17, 2009 by sinbin

[Maizefarmer]

Please excuse my ignorance but I've just read the above and I'm somewhat perplexed. When 'cassava' is harvested the stems and leaves are then ploughed into the soil. If 'cassava' is poisonous, then that means that all 'cassava' grown land is then toxic ? So anyone building on, previous, 'cassava', planted land is building on contaminated land. If the toxin is only in the root then leaving any unharvested tubers in the soil still contaminates the land. Right or wrong ?

Correct - there is a strong correlation between bitterness and toxicity - the more bitter, the more toxic. But that toxicity is not permanent - thats one reason why folk cut the tuber up and dry it out (the other is that is decomposses and looses all value if harvested and stored "wet"). As it breaks down and decomposses back into the soil - real world potential for poisoning is negliagable. Don't worry about - you'll be quite safe.

[sinbin]

Thanks for those reassuring words 'Maizefarmer' but let me just quote this statement from Junji Takano, a Japanese health reasearcher. "I feel that cassava poisoning may cause some brain damage related to the pituitry gland that causes other damage to various organs. No wonder the Japanese Ministry of Health prohibits the use of cassava for human consumption".

If the Japs don't eat the stuff then that's a good indication for me to stay well clear of it, as they seem to consume everything else, including poisonous Puffer fish.

Edited October 18, 2009 by sinbin

[Maizefarmer]

Well, I don;t know enough about the stuff to challenge that, except that it is eaten in many parts of the world with little or no apparent health effect, though I have to say it's not very tasty however prepeared. I think those folk in Africa (where it is popular) who do eat it, eat it not out of preference, but out of circumstance. Pesonaly on the few occassions I have been served a dish with some part of cassava in it, however spiced up or mixed up with whatever else is on the plate, I have never liked the stuff.

Its a useful additive to livestock feed - one of its big uses in Thailand, otherwise the market for it is dried out and crushed up to form a starch base in procssed products.

Yer- the Japanese do eat some odd stuff, but the tend to live to a ripe old age - down to their high fresh fish intake - they are ever so careful to cut out the bits from that puffer fish they eat, but despite all the effort and care they go to, every year in Japan there are several incidents in which the old puffer fish has the last laugh!!!

Edited October 18, 2009 by Maizefarmer

[Ijustwannateach]

Cassava does need some processing to be safe to eat, but it has been a staple in Africa for thousands of years so I doubt it could be too harmful.... one should also be aware that the Japanese government tends to be somewhat conservative, and many conservative Japanese have curiously racist notions about their food- for example, did you know that Japanese people have a special digestive system which can only process Japanese rice? (some Japanese people believe this so literally that when they travel abroad they bring their own rice). Also Japanese rice is the best and most tasty and nutritious in the world, etc., etc. I have met Japanese who got into fights when other Japanese challenged them on this.

[sinbin]

I agree that 'cassava' is eaten by millions of poor people around the world, but is it permisable to let them slowly poison themselves over a period of years than to let them starve in agony over a short period ? I personnally think that governments do. In Africa they do actually have problems with 'cyanide' poisoning after long exposure to people eating 'cassava' tubers.

I also agree that 'cassava' is used in "livestock feed", but the Thais give it uncooked, and that is not recommended, by all that I've read. Therefore the possibility of 'cyanide' being in the food chain ? As I've said before I'll "stay well clear of it".

Edited October 19, 2009 by sinbin