Edible bulbs

totototo@telus.net totototo@telus.net
Thu, 01 Apr 2010 17:34:40 PDT
On 31 Mar 2010, at 13:39, Mary Sue Ittner wrote:

> On [the wiki page "edibles"] was listed Colocasia esculenta, a plant used in
> Hawaii for a food known as Taro. This man and his wife had made a stew using
> this plant instead of potatoes using a published recipe. It tasted strange
> so they spit it out, but she ended up in an emergency room. He gave me links
> to sources of information about this and how it could cause a severe
> itching, stinging, or burning sensation in the mouth and throat, followed by
> swelling and other effects, or a less severe irritation or itching sensation
> on external skin (on hands and arms for example). It took his wife 12 days
> to recover completely. 

Colocasia, according to one online reference coughed up by Google, must be 
cooked "properly" to remove its toxic properties. The toxin is calcium oxalate, 
which is destroyed by heat.


The issue, it appears to me, is that this couple simply did not investigate 
thoroughly enough before forging ahead with their taro-laced stew, and ended up 
not cooking it properly.

Another potentially dangerous edible root is that of manihot or cassava, the 
source of tapioca starch. The crude root contains cyanogenic glycosides, which 
release dangerously poisonous cyanide via hydrolysis. The Amazonian Indians 
developed quite sophisticated equipment for squeezing the toxic juice out of 
crude cassava, rendering it fit for consumption.

> By saying that a plant has been used as a food source, we fail to say 
> how it is processed to make it safe.

It's entirely one thing to say "this plant has been used as food" and another 
to infer that no special processing is required. There are many foods that must 
be processed just so if they are to be eaten, not just taro and cassava. The 
puffer fish can be eaten but the greatest care must be taken to remove the 
tissues containing teradotoxin, which is an extremely dangerous poison with no 
known antidote.

However, sometimes the novelty of finding out that a given plant has been used 
for food leads to intemperate discussion of it. An example is rue, which as far 
as I know is not palatable, and may be toxic, but which is described with 
little gasps of delight as having been used in salads. Phooey on that!

> Indians in our area used acorns from a tree as a food source, but there was
> a lengthy process that was needed to remove the toxicity. 

Another case in point.

> Do we know if all Alliums are equally edible? I'm sure that some taste
> better than others, but that is not my question. My question is whether they
> are all safe to eat. 

Mark McDonough, who may be a subscriber to this mailing list, once commented in 
a lecture that one of the virtues of growing alliums is that if you don't like 
them as garden plants, you can always slice them up, fry them, and eat them 
with steak. I infer that the entire genus is salubrious.

Be aware that ordinary culinary alliums are toxic to dogs and cats.

Rodger Whitlock
Victoria, British Columbia, Canada
Maritime Zone 8, a cool Mediterranean climate
on beautiful Vancouver Island


More information about the pbs mailing list