Re: [RC] catching up re beet pulp, pt. 2 - Sisu West Ranch
The comments on the removal of nutrients by the
oxalate in beet pulp sent me to my book shelf. I looked up the solubility
products of oxalates. For non-scientests in the group I should define
scientific notation and solubility product. Please bear with
me.
In scientific notation 10^-2 = 0.01 the "^"
is a way to indicate exponents when good typesetting is not around. the
larger the negative exponent the smaller the number. 10^-9 is 0.000000001
or one in a billion.
Cations are derived from metals, and carry a
positive charge (Sodium, Potassium, Magnesium, and Calcium are examples of
metals that are usually found as cations)
Anions are the negatively charged part of inorganic
compounds. They are derived from non metals and organic compounds.
Most are also found in acids of the same name. Acetic acid reacts with Na
to form sodium acetate etc. Some important nutrients are actually found as
anions. Phosphorous is really in the body as phosphate.
The concentration of inorganic compounds (those
with cations like Na (sodium) or Ca (calcium) and anions like Cl (chloride) and
phosphate (PO4)) dissolved in water can be expressed by the product of the
concentration of the cation and the anion.
The smaller the product, the smaller the solubility
product.
Ca oxalate has a solubility product of 2 x
10^-9
Mg oxalate has a solubility producto fo 8.6 x
10^-5.
This means that very little Ca oxalate dissolves in
water. It also means that oxalate will remove Ca from
availability 10,000 times as well as it will Mg. Note that since food
normally has more Ca than Mg, most of the oxalate will be tied up by the Ca with
little left over to react with Mg. This would cause me to predict that
effects would be seen first on Ca availability.
I couldn't find my old inorganic text to check, but
Se is in the Sulfer family of elements. That means that while it can be
found as a cation, (SeBr2 is known, but decomposes in water) like Sulfer it
should usually be found as salts of Selenic or selenious acid. This means
it is part of a negatively charged anion. Oxalate will not react or
precipitate another anion. Note that since Se is so poisonous, it is not
usually encountered in the chemistry lab, that is why I tried to find my old
inorganic text. Be aware that I may be wrong here, but I doubt
it.
Ed
Refs:
"Qualitative Analysis and Electolytic Solutions"
Edward J King, 1959
"Handbook of Chemistry and Physics", Chemical
Rubber Publishing Co. , about 1959 (the cover is gone)
Ed & Wendy Hauser 2994 Mittower
Road Victor, MT 59875
