Hi Jeff said:If I dissolve calcium from eggshells using vinegar, how
much calcium can I get from one eggshell, how much 5%
vinegar do I need andhow usable for my body is it?
That's one of the best questions I have ever seen in this
news group. It comes in three parts and deserves an
answer. I'll try to answer part of it now and will do some
research and hopefully find a complete solution to your
worthy request.
It is a shame that the weak responses in this thread so far
have left such a good inquiry unanswered.
Many postings in this group are by persons trying to push
their own ideas about nutrition and health. Many are looking
for a place where they can sound clever. They cite
questionable scientific studies right along with peer-
reviewed papers published in reputable, well-known journals
as a method to promote themselves. It didn't used to be this
way. At one time this was one of the finest forums on the
Internet with some of the keenest minds offering generous
and well-organized material.
Jeff, sorry about my rant. Let me get to the specifics of
your eggshell-calcium chemistry question. First, it might be
helpful to know where you got the idea to dissolve eggshell
with vinegar. (I remember an experiment in grade school that
enabled an unpeeled hard-boiled egg to pass through the neck
of a milk bottle by first softening the shell by treatment
with vinegar.) Perhaps the source(s) that initiated your
inquiry might offer clues for further investigation.
Just a note for caution: Are eggshells safe to consume?
Mom's recipe offered by Ora gives us some "folk-wise" and
perhaps scientificaly valid advice:
Quoted message said:Eggshells should be crushed thoroughly, baked (stirring
occasionally) on a cookie sheet until brown and then mixed
with sugar. That kills the salmonella.
If microbes such as salmonella were the only danger to
consider when planning to ingest eggshells then Ora's recipe
would probably render the product safe. On my bookshelf from
the textbook _Microbiology: Principles & Applications_ JC
Creager (1990) p324~
Quoted message said:Objects are sterilized by dry heat when subjected to
171=B0C (340=B0F) for 1 hour, 160=B0C (320=B0F) for 2 hours
or longer or 121=B0C (250=B0F) for 16 hours or longer
depending on the volume.
This type of heat treatment will kill all microbes including
the resilient spore-forming bacteria. Eggshell salmonella
would die long before any of these rigoroulsy controlled
conditions for complete sterilizations were reached.
The "browning" that Ora describes in her mother's recipe
comes from organic compounds breaking down and releasing the
basic carbon (dark color) atoms that bind together the very
chemicals that carry out the processes of life. The browning
indicates the destruction of the potential for any microbes
to live. I should mention also that the brown is mostly
coming from the proteins and other organics naturally found
in eggshell, not from a plethora of dangerous salmonella.
I believe that Ora's heat treatment (from now on to be
called "Orafication" `o-rah-fi-`c=E5-shun) would make
eggshells safe to use if salmonella was a potential danger.
But would Orafication alter the chemistry of eggshells in a
way that would effect the calcium product obtained with
vinegar? It is possible, but I don't know enough chemistry
to say for sure.
As you mentioned, Jeff, eggshells contain calcium carbonate
CaCO=B3... Calcium carbonate is also found as the major
constituent of Limestone. This common yet valuable mineral
is ground and heated in kilns to make "lime" in the form of
"quicklime" and also treated further to make "slaked lime".
The chemistry of the process isn't too complicated and could
be related to Orafication. I think the major difference in
outcome of the two processes would arise from the two
different heating procedures.
In heating the Calcium carbonate of limestone the carbonate
liberates carbon dioxide to leave calcium oxide (quicklime):
heat + CaCO=B3 ---> CO=B2 gas + CaO
The quicklime absorbs water from the air and from liquids
that contain water. Industrially water is added to quicklime
to form the "slaked lime" (calcium hydroxide) that is used
in cement:
CaO + H=B2O ---> Ca(OH)=B2 + heat
I don't think that any such reactions would matter or occur
during Orafication because the household ovens are not
generating the type of heat used in the industrial
processing of limestone. I think that Calcium carbonate
releases its Carbon dioxide at about 890=B0C which is about
1634=B0F and far above the temperature in the oven that
Ora's mother used.
To wrap up the question as to whether or not pre-heating
eggshell would effect chemical combining of CaCO=B3 with
vinegar: probably not much in an inorganic/organic acid
chemical reaction pathway, but the breakdown from oven heat
of large protein molecules might render the eggshell more
permeable and available to react with the acetic acid.
To continue with the safety issue I quote the comment made
PizzaGurl:
Quoted message said:Salmonella live in 5% acetic acid?
Salmonella would probably not survive long periods in 5%
acetic acid (vinegar). This acid is produced by bacteria as
a waste product and is, as it accumulates, eventually toxic
even to the bacteria of origin. Furthermore, vinegar is used
as a preservative against microbes in the form of a pickling
solution. Hot vinegar would, I assume, most assuredly kill
salmonella.
Acetic acid is considered chemically to be a weak acid. But
on the other hand it finds use as a powerful solvent in
organic chemistry. This may be the reason why vinegar is so
good of a preservative.
One more note about the safety of eating eggshells before I
comment about the chemistry. Years ago, before the expansion
of the Internet, I asked about the safety of eating
eggshells as a source of Calcium. I was informed by Dr. G.
Ho, PhD, Professor of Nutrition Studies, UCLA through
personal correspondence that CLEAN eggshells were indeed
safe to consume.
I used to ingest eggshells in order to increase my daily
Calcium intake. First I boiled the eggs, then cooled them,
peeled them and set the shell out to dry. After a day or so
I placed the dried shells on a shallow cookie pan into a
medium hot oven (gas operated). I removed the shells after
about 30 minutes or just when they started to brown. Very
similar to orafication.
I set the oven-browned shells on the counter to cool to
room temperature. I then placed as many as I could into a
small coffee bean grinder and powdered them. This took
about 45 to 60 seconds. I ran the powder through a fine
sieve to winnow out any larger bits of shell or extraneous
membrane. To use, I measured a small amount of powder by
spoon, placed the powder into my mouth and then swallowed
it with a glass of water.
I never suffered any ill effects from my eggshell
concoction. In fact there were a few times that I had used
the eggshell powder to successfully alleviate an upset
stomach. The powdered eggshells were mostly Calcium
carbonate, the same active ingredient found in antacids such
as Tums=AE.
And now Jeff, what about eggshells treated with vinegar? The
calcium carbonate and the acetic acid probably react to form
calcium acetate. But like I said before I don't know enough
chemistry to give a worthy opinion about this.
A textbook I have claims that Calcium acetate also has two
other forms that occur as hydrates. All three compounds are
colorless solids that when heated decompose before they can
melt and are all soluble in hot or cold water.
I have never seen calcium acetate being used as a
nutritional supplement. I don't know why it would be
excluded. There are other calcium salts made from organic
acids that are used as sources for increasing calcium
intake. For instance I have seen being used calcium
gluconate, lactate, citrate, maleate... being made from the
organic acids respectively gluconic, lactic, citric, maleic.
Calcium acetate might have a storage problem or have an off
odor or flavor. It might not be as stable of a molecule as
the other acid compounds. It may be too reactive and
combines too easily with other common ingredients. Or
perhaps when making calcium acetate the heat might destroy
the compound before a useful product can be obtained.
I will do some reading and will comment later if I find
anything useful. I wish I had better grades in my chemistry
class in school. I hope some knowledgable person comes along
to answer this question. I would certainly like to know. I'm
not much of an "egghead". ha ha
It may end up that the only way to completely answer this
question is by experimentation.
Sub C=F8dex
