I am thinking of making tofu.
Regular coagulants for the soy protein to make tofu are Calcium
Sulphate (gypsum), Magnesium Chloride (nigari), or Magnesium Sulphate
(epsom).
My chemistry is really bad, so I need help. I am thinking of
substituting the Calcium or Magnesium in the coagulant process with
Potassium.
My question is, can I use Potassium Chloride or Potassium Sulphate
(potash) to be the coagulant for tofu ?
Would it be possible?
Would it be poisonous?
I wouldn't bet on much coagulation, but I'm not a chemist.
Keep in mind that Ca and Mg are both column II; K is
column I.
> Would it be poisonous?
Not in reasonable amounts, and you'd have to use a LOT
of K to be dangerous -- enough that it would taste nasty.
--
| Shit happens. Sometimes it happens to you. |
+--- D. C. Sessions <d...@lumbercartel.com> ---+
KCl is highly poisonous. Don't use it.
Exactly, it can kill you and it can be very painful.
I am not a professional chemist but I think that I can help some.
The purpose of the salt is to discharge any residual charge on the
colloidal particles. This removes the repulsive forces and allows the
particles coalesce into larger particles (coagulation). Almost any
electrolyte solution should do that.
Potassium ion is not highly toxic, but it can interfere with the
functioning of nerves including those keeping the heart beating
properly. At the least, I would want to know how much potassium is left
in the tofu and how big a dose you get. Also run it by your doctor or
pharmacist to find out how much trouble you can get into. Certainly,
large amounts of the other substances you mention can get you into
trouble. It just depends on the dose.
Gypsum is not highly soluble. That would indicate to me that you do not
need high concentrations to coagulate. Certainly, epsom salts is not a
problem in lw doses. Larger doses will keep you visiting the bathroom. I
presume really large doses are harmful.
I believe that potash is potassium carbonate, not the sulfate.
Bill
From Wikipedia --- http://en.wikipedia.org/wiki/Poison
"Intravenous injection of an unnaturally high concentration of
potassium chloride, such as in the execution of prisoners in parts of
the United States, quickly stops the heart by eliminating the cell
potential necessary for muscle contraction."
Keywords above are "Intravenous Injection" & "Unnaturally High
Concentration"
Unless all the potassium chloride got into the blood, and that guy
eats a truck load of tofu, I don't think his heart is going to stop
contracting.
:)
Bob M
www.molab.co.nz
Potash ash is crude potassium carbonate as I recall.
I suppose potassium sulfate might work though the
working end of the deal if it works would be the sulfate
anion given it minus two charge. It likely would work.
I'd rinse the curd. The remain dose of potassium should
be pretty low, likely doing no more than replacing some
of the K+ which is lost in the processing of the beans.
The other issue would be the issue of the purity of
the various proposed salts here and what else they
might contain.
Sample carefully in case I missed something and it
is going to kill in larger doses ;-) Before you take
your next breath ask your Doctor whether it is safe
and whether it is good to continue. Hold that breath, now.
> I'd avoid the potassium chemicals. I've tried the potassium based
> baking powders in the past and it alters the taste and not in
> a favorable way. Though this does indicate the nervous
> Nellies concerned that a trace of potassium will kill is
> overblown and reflects a lack of understanding of
> what is going to be eaten here that is the solid not the
> liquid. If one drinks pickle brine don't be surprised
> if one gets a trip to the ER for congestive heart failure
> due to the excess NaCl. Don't drink brine whether it
> contains Na+ or K+.
Let's keep things in perspective here. The RDA for
potassium is 3000 mg. You can eat a potato without
danger of dropping over from the potassium content.
Morton "Lite Salt" is something like 40% potassium
chloride. I use the stuff all the time as a supplement.
No.
Dangerous Bill
Most people are okay, but certain people, or people taking certain
blood pressure medicines can develop heart irregularities.
But for the tofu thing, potassium is probably the last choice anyway.
Buy some calcium capsules and empty them (or crush up some drywall if
you want) and some epsom salts (magnesium sulfate).
Dangerous Bill
There are sites that state the RDA was increased to 4700 mg. The max
daily amount is somewhere in the neighborhood of 21,000 mg and paleo man
is estimated to have consumed daily 11,500 mg of potassium.
Clearly, the RDA is not the "optimum" daily amount, it's the minimum.
--
Pramesh Rutaji
p297ton...@newsguy.com - remove tongue to reply
Don't be silly.....crush drywall. Do you realize makers add
anti-mold additives to the stuff. I won't even put the
remainders from my dry wall work in hole in the garden, rather, I send
it to the land fill in the next state.
I'd go for it if I knew how to make tofu. The worst that could
happen is that it would taste bad. Can you make it from soy milk?
--
Marshall Price of Miami
Known to Yahoo as d021317c
Do you know which soft drinks contain significant amounts of
phosphoric acid?
All food is liquified by the time it reaches the duodenum. However,
the duodenum is the location where the gastric juices are flooded with
large amounts of potassium secretion from the pancreas. The
intestinal bioavailability of potassium is actively controlled by ion
pumps at the cellular level, and that is the reason why the GI route
has a certain safety margin over the intravenous route. However, even
the gastric route can be overwhelmed. Most especially in people with
any level of kidney impairment or blood flow to the kidneys such as in
any type of heart failure or prolonged severe hypertension as the
kidney is the only route of egress from the body for potassium (except
for bilious vomiting). Hyperkalemia is a life-threatening emergency
precisely because it is so difficult to remove from the body, and
because the concentrations for optimal function are so low (two orders
of magnitude lower than sodium) that it does not take much to exceed
safety margins.
Be aware, also, that the amount of potassium chloride required to
cause conduction abnormalities in the heart is nowhere close to the
dose used in Lethal Injection which is unnecessarily high in order to
never be in the margin of error when executing a prisoner (what a
bloody disaster that would be). Potassium chloride is never used as a
direct injection in the ICU as being far too dangerous. Patients who
required potassium supplementation always received it very slowly and
gradually over a period of time, massively diluted in the IV.
The upshot of all that is that using it to make tofu is likely safe
for a totally healthy individual, but not exactly a first choice if
one plans to eat a daily diet dominated by it, and not if the
individual has any reason to be concerned about cardiac or renal
function. Moderation is the key.
--tension
The brine is drained off and not eaten. Hence a share of
the potassium would do down the drain, if it is even
effective.
Tofu isn't on my food list of late. Too many isoflavones
for my taste :-(
>
> --tension
By the way, Bob M has a discussion about phosphoric acid on his
website which confuses me:
http://www.molab.co.nz/pages/cola-osteoporosis.php . Any comments on
how he gets "50%" -- and what he means by it?
What do you put in your miso soup?
> By the way, Bob M has a discussion about phosphoric acid on his
> website which confuses me:
> http://www.molab.co.nz/pages/cola-osteoporosis.php . Any comments on
> how he gets "50%" -- and what he means by it?
You mean 50% like in 50% neutralization? It means nothing. To get pH 5.5
you have to neutralize a little bit more than first proton, say 0.1M acid
plus 0.105M NaOH. If the 50% refers to real 50% - you end with perfect
pH=pKa2 buffer, that gives pH close to neutral (pKa2=7.2).
Borek
--
http://www.chembuddy.com/?left=BATE&right=pH-calculator
http://www.chembuddy.com/?left=Buffer-Maker&right=buffer-calculator
This is still way over my head. Could you elaborate a little more?
>>> By the way, Bob M has a discussion about phosphoric acid on his
>>> website which confuses me:
>>> http://www.molab.co.nz/pages/cola-osteoporosis.php . Any comments on
>>> how he gets "50%" -- and what he means by it?
>> You mean 50% like in 50% neutralization? It means nothing. To get pH
>> 5.5 you have to neutralize a little bit more than first proton, say
>> 0.1M acid plus 0.105M NaOH. If the 50% refers to real 50% - you end
>> with perfect pH=pKa2 buffer, that gives pH close to neutral (pKa2=7.2).
> This is still way over my head. Could you elaborate a little more?
Very generally speaking, phosphoric acid neutralization goes like that:
H3PO4 + 3NaOH -> Na3PO4 + H2O
50% means that you add half the amount of NaOH required. This in turn
means that you:
1. Proceed completely with first step of neutralization, ie
H3PO4 + NaOH -> NaH2PO4 + H2O
2. Proceed 50% into the second step of neutralization:
NaH2PO4 + NaOH = Na2HPO4 + H2O
So, after 50% neutralization your solution is 50/50 H2PO4- and HPO4-2.
This is a classic buffer solution, with pH described by so called
Henderson-Hasselbalch equation, which in this particluar case takes form:
pH = 7.2 + log([HPO4-2]/[H2PO4-])
but we already know that [HPO4-2] = [H2PO4-] (remember, solution is
50/50). That leaves us with
pH = 7.2
There are fine details omitted and hidden assumptions done so nitpickers
can bash almost every phrase in this post, but no matter how the'll try,
their final pH will be around 7 as well.
To get solution with pH around 5.5 you have to neutralize first proton and
add very small excess of base. I would call it 35% neutralization
(assuming 100% is when the amount of base is three times that of acid, to
account for the phosphoric acid "triprocity").
Now, you can define 100% neutralization in terms of single proton - ie
100% is when the reaction
H3PO4 + NaOH -> NaH2PO4 + H2O
is finished. That means full neutralization is 300%. This approach
sometimes simplifies calculations. Still, 50% in this case is when you
have 50/50 mixture af H3PO4 and H2PO4- - this is another buffer, with pH
around 2.2. No matter how you try it is NOT 5.5.
Browse pH calculation lectures at
http://www.chembuddy.com/?left=pH-calculation&right=toc
if you need more. Or play with pH calculator from
http://www.chembuddy.com/?left=BATE&right=pH-calculator
to see for yourself how the pH changes for different solutions. There is a
30 day free trial so you can do it for free.
Borek
--
http://www.chembuddy.com/?left=Buffer-Maker&right=buffer-calculator
Wow. Thank you very much. (No wonder I didn't get it!)
When you say "full neutralization is 300%," is that because you need
three times as many molecules of NaOH (sodium hydroxide) as you have of
H3PO4 (phosphoric acid)? Why did you use NaOH in the example?
(Since I see phosphate groups so often in metabolic reactions, I was
surprised to read that the phosphoric acid in soft drinks might cause
problems.)
Molony says:
-----
Foods contain ... two groups [of acids];
[M]etabolisable acids ... which can be broken down and completely
destroyed For example citric acid, acetic acid, lactic acid etc.
And
[N]on metabolisable or fixed acids which are not destroyed by the body.
For example hydrochloric acid, sulphuric acid, phosphoric acid etc.
-----
Are these two categories simply (1) organic and (2) inorganic acids,
or is that too simple?
> When you say "full neutralization is 300%," is that because you need
> three times as many molecules of NaOH (sodium hydroxide) as you have of
> H3PO4 (phosphoric acid)?
Yes, that's neutralization stoichiometry.
> Why did you use NaOH in the example?
Why not? :) Neutralization reactions are easiest to analyze when you use
strong acids/bases in calculations. NaOH or KOH are commonly used for that
purpose when speaking acid neutralization, HCl - when speaking about base
neutralization.
> -----
> Foods contain ... two groups [of acids];
>
> [M]etabolisable acids ... which can be broken down and completely
> destroyed For example citric acid, acetic acid, lactic acid etc.
>
> And
>
> [N]on metabolisable or fixed acids which are not destroyed by the body.
> For example hydrochloric acid, sulphuric acid, phosphoric acid etc.
> -----
>
> Are these two categories simply (1) organic and (2) inorganic acids,
> or is that too simple?
It can work as a first approximation, but it is very likely there are
organic acids that'll will be not metabolised.
That's what I thought. (I'm trying to catch up on the chemistry I
missed when I dropped out.)
They'd be organic, but not carboxylic acids?