Jana Eagle wrote:
>
> I would be interested in knowing more about why meat is supposed to be
> more digestible when cooked, because I have never heard this.

From Harold McGee, "On Food and Cooking", page 596:
"Finally, because they are extended, denatured proteins are more
vulnerable to attack by protein-breaking enzymes, which depend on access
to the backbone chain. For this reason, cooked meats are more digestible
than raw."

This was after a couple of pages of discussion of protein coagulation,
disulfide bonds, and denaturation via acid, salt, or heat. In this next
quote I've continued on a bit beyond the first sentence which mentions
meat digestibility, because there's more that is pertinent to "cooked
vs. raw".

From page 105:
"We cook meat for four basic reasons: to make it safe to eat, easier to
chew and to digest (denatured proteins are more vulnerable to our
enzymes), and to make it more flavorful. Fortunately, the issue of
safety is a minor one today. We all know to cook pork to at least a
medium doneness (an internal temperature of 150F gives a 13 deg. safety
margin) to kill any trichinae present. Aside from this, all that is
called for is sensible hygienic care in handling the food. In the rest
of this chapter we will concentrate on the physical and chemical
transformations of meat during cooking, and their effects on our
impressions of texture and taste. A few words, though, about meat
cookery and nutrition. One of the inevitable consequences of cooking
meat is the loss of some juice, whether to the roasting pan or the stew
liquid. Generally, the longer or hotter meat is cooked, the more juice
will be squeezed out of it. These fluids are made up primarily of water,
fat, and soluble vitamins and minerals. The B vitamins, one of meat's
nutritional specialties, are carried off in the watery juices. The loss
of fats results in a reduction in the meat's calorie content and removes
some vitamin A, which is fat-soluble and responsible for the yellowish
color of fat in older meats. High temperatures will destroy some
thiamine, but cooking doesn't really hurt the meat's nutritional value
unless it is grossly overdone. If you recoup the fluid losses by making
gravy from the drippings or a sauce from the braising liquid, the
nutritional decline will be slight".