I received a message today from Malcolm Klein, whom requested that I
post
the following message for him. He mentioned he was unable to post this
to the list.

Anyway, here's some more great information regarding raw vs. cooked
starch.
Enjoy!

--
Actually there is a lot of recent research on the advantages of slowly
digested starches.  There are a number of physical/chemical factors
involved.  First, there is the physical structure of the starch itself,
which is stored in plant cells in bacterial sized sacs called starch
granules.  If you look at a potato cell under a microscope you will see
20-50 balloon like sacs inside each cell.  THe starch in these granules
has been concentrated there by the plant cell to such a degree that it
is nearly in a CRYSTALLINE state and thus only the outer layer is
accessible to your digestive amylase enzyme, so digestion takes place
very slowly as each layer of the granule becomes gradually exposed, like
layers of an onion!  Any degree of cooking, however, will totally
disrupt this dehydrated structure and the granule swells up and becomes
totally permeable to the amylase enzyme so that the entire granule
becomes accessible to the enzyme simultaneously!  The starch chains are
quickly broken down into maltose and then glucose and rapidly absorbed
in the first few feet of the upper intestine.  Amazingly enough many
cooked starches like potatoes and rice have very high glycemic indexes (
a measure of how rapidly glucose enters the bloodstream) higher even
than pure table sugar/sucrose! (Because sucrose is only 50% glucose- 50%
is fructose which doesn't affect blood glucose- while starch digests to
100% glucose)

Second, in the case of legumes, their starch granules remain trapped
within very tough cell walls even after cooking, so that again the
amylase enzyme is denied easy access to the starch.  This accounts for
their slow rates of digestion and moderate effect on blood glucose.  (
in fact if you pulverize the beans BEFORE cooking, you can break up the
cell walls and then after cooking they will digest just as rapidly as
potatoes or rice!!)

"The Effect of cooking upon the Blood Glucose Response to Ingested
Carrots and Potatoes" DIABETES CARE  V 7:p221 1984

"Slowly digested and absorbed carbohydrate in traditional bushfoods:a
protective factor against diabetes?"AM J CLIN NUTR V45:p98 1987

"Effects of cooking on serum glucose and insulin responses to starch" BR
MED J V282:p1032 1981

"Cell structure and starch nature as key determinants of the digestion
rate of starch in legume" AM J CLIN NUTR V43:p25 1986
--

Malcolm L. Klein
[log in to unmask]