Subject: Re: Food Additives
From: Jay_Mann@equinox.gen.nz (Jay Mann)
Date: Jun 13 1995
Newsgroups: sci.bio.food-Science

Mike Montgomery (mlm@mindspring.com) wrote:
: I am working on some research and could use the help of those knowledgeable in 
: food science. I understand that the use of fibers in dietary foods and animal 
: foods may include materials such as cotton fibers. Does anyone know any 
: details on this. My understanding is that cotton is turned into cellulose 
: (how, I am uneducated to), and this acts as the filler in dietary breads, 
: cereals and baked products.

I think you have your facts a__-about.  Cellulose is a natural component of
the cell walls of plants, which includes potatoes, cereals (wheat: the main
ingredient in bread), etc.  Cotton is a plant product that has economic
value because of its long cellulose fibers.  Just because cellulose is a
component in, say, potatoes, does not mean that potatoes contain ground-up
cotton.

There are two broad classes of "dietary fiber": soluble and insoluble.  The
insoluble fiber, typically coming from wheat bran, helps to soften stools
(motions), forming something like papier mache in the gut.  Insoluble fiber
is, primarily, cellulose.  Then there are soluble fibers (pectin, pentosan,
and glucans), which come from such materials as fruits, barley, oats, etc.
(I'm only listing foods with notably high levels of these materials.) The
nomenclature "fiber" is IMHO an abomination that is too strongly entrenched
to change.  "Soluble fiber" tends to form gels in the gut, helping to delay
the absorption of other food components, which is good for overweight people
but bad for growing broiler chickens. There is evidence that soluble fiber
reduces cholesterol levels, perhaps by carrying bile salts (made in the body
from cholesterol, and functioning as detergents) out of the gut.  Some
people believe there are specific chemical bonds with the soluble fibers,
but I think it's primarily a viscosity affair.

When soluble fiber reaches the large intestine (colon), the bacteria there
usually can break it down, sometimes with production of gas.  

The usual recommendation is 2/3 insoluble fiber, 1/3 soluble fiber for human
nutrition.  But food labels don't distinguish between soluble and insoluble,
unfortunately.  Just remember, oat bran is better than wheat bran, in terms
of soluble fiber.   Also note that viscosity (thickness) of glucan and
pentosan solutions is exponentially related to concentration: half the
concentration can mean only 5% as much viscosity.  So if viscosity is the
key, don't crib on your fiber intake.

Jay D Mann  <jmann@equinox.gen.nz>
Christchurch, New Zealand

Subject: Re: Sources of cereal fiber sought
From: mannj@southern.co.nz (Jay Mann)
Date: Sep 11 1995
Newsgroups: sci.med.nutrition

The Toad (notpc@ix.netcom.com) wrote:
: My gastroenterologist says I must eat more fiber, and only CEREAL
: fiber will do.  (Fruit fiber won't "do," etc.)
: 
: I know about All-bran.  Awful stuff!  Raisin bran is better.  Bran
: muffins--ok.  Oatmeal--pretty good.

If we can get decent-tasting high-fibre cereals here in New Zealand, you
must be able to find a bigger variety in the States.  I mix the bran-type
cereals with more palatable cereals, rather than eat a whole bowl of them. 
Remember, check to see if your stools (feces) float.  If they don't, you
need more fibre. 

Be careful to get both oat fibre and wheat fibre.  Oat fibre is a
different kind, mostly "soluble fibre", that is, gel-forming polymers. 
Barley fibre is similar to wheat fibre.  But wheat bran fibre is less
soluble, and closer to eating ground-up newspaper pulp.  You need about
two parts wheat-type to one part of oat-type fibre. 

Jay D Mann  <mannj@southern.co.nz>
Christchurch, New Zealand