On Thu, 30 May 2002 17:14:55 -0400, Todd Moody <[log in to unmask]>
wrote:


>I'd be interested in learning more about this claim: "Surveying
>the literature, Dr. Wrangham and his colleagues determined that
>of the 48 types of roots, tubers and other potatolike plant foods
>eaten by humanity's foraging African forebears, 21 require
>cooking to be comestible."
>

You can look in the Wrangham paper:

From C u r r e n t A n t h ro p o l o g y Volume 40, Number 5, December 1999

The Raw and the Stolen
Cooking and the Ecology of Human Origins
by Richard W. Wrangham,
James Holland Jones, Greg Laden,
David Pilbeam, and
NancyLou Conklin-Brittain

"The combined importance of these mechanisms can
be categorized broadly as enlarging the diet and improving
its quality. Both of these bene.ts are relevant for the
use of underground storage organs. First, these organs are
often chemically protected, apparently as a result of coevolution
with mammalian herbivores (Lovegrove and
Jarvis 1986). In our survey of underground storage organs
eaten by African foragers, 21 (43.8%) of the 48 edible
species identi.ed required cooking to become palatable.
This suggests that cooking can substantially broaden the
range of edible species. Furthermore, underground storage
organs are frequently considered to be improved by
roasting (e.g., Silberbauer 1981). This may be partly a
matter of macronutrient availability. For instance, Ayankunbi,
Keshinro, and Egele (1991) found that three
modes of preparing cooked cassava led to a mean increase
in gross energy available of 76.1% over the value for raw
cassava (306 kcal/g compared with 174.0 kcal/g). Potato
starch, the principal source of digestible energy in potatoes,
is highly resistant to amylase (the enzyme primarily
responsible for converting complex carbohydrates
into usable energy) when raw but rapidly digestible when
cooked (Kingman and Englyst 1994). ......."