Sciencemadness Discussion Board - how to make "low pH but no sour" solutions

how to make "low pH but no sour" solutions

mobiusxx - 27-4-2014 at 00:04

Its related with my post before,
"https://www.sciencemadness.org/whisper/viewthread.php?tid=29917#pid325793"

after i used calcium hydroxide to reduce citric acid in my solutions,,,and its worked,,,the solutions has inrease the pH and the sournes become lower than the solusions that not added by Ca(OH)2,,,

the equation is
3Ca(OH)2 + 2C6H8O7 => Ca3(C6H5O7)2.4H20 + 2H20

if i use Ca(OH)2 like the equation above,,,the ph solutions is near normal solutions,,its about 5-6,,,so i only use 70 percent of the supposed,,,

with the 70% Ca(OH)2, the pH of solutions become 3,6,,,

and because my aim is to make isotonic drink,,,and the pH of isotonic drink is should not be more than 4,,,so 3,6 its okay,,

but the problem still remains,,, because with pH 3,6,,the taste is still sour,,,although the sour taste is very much reduced than before,,

i 've been formulate the drinks,,,if the concumption of my drink is only 100 or 150 ml,,,with a exist sour taste in my drinks, I think my formulation is still acceptable,,

but for adequate anthocyanin intake, its need to drink as much as 500 ml drinks,,,and to consume as much as it is, plus with the sour taste,,,it will not acceptable,,,

and my question is,
is there any way to reduce the sour taste without/not too much increase pH of the solutions???
because if the pH is too high,,its not isotonic drink,,and the anthocyanin is not stable in pH above 4,,,,

I hope you understand what I mean,,,sorry if my english is bad,,,

Thank You,,,

[Edited on 27-4-2014 by mobiusxx]

how to make "low pH but no sour" solutions

deltaH - 27-4-2014 at 00:12

Add sugar? Lemonade tastes terribly sour without sugar

Aside from that, is one other thing that might help, having more potassium in there... I quote from Wikipedia section 'Sour' from it's english article on 'Taste':

Quote:

According to this mechanism, intracellular hydrogen ions inhibit potassium channels, which normally function to hyperpolarize the cell. By a combination of direct intake of hydrogen ions (which itself depolarizes the cell) and the inhibition of the hyperpolarizing channel, sourness causes the taste cell to fire action potentials and release neurotransmitter. The mechanism by which animals detect sour is still not completely understood.

So I would recommend adding a little potassium hyroxide, as much as what does not raise the pH above the maximum you need for your anthrocyanins (3.8 is probably a good target). That may help to reduce the perceived sourness a lot.

Incidently, I have experienced this effect myself with potassium bitartrate (cream of tartar). A saturated solution of cream of tartar has a pH of around 3.6 (it is a buffer), which is quiet low, but tastes only mildly sour with sugar added.

Check that the amount of potassium you use is acceptable in terms of a persons nutrional requirements. Don't forget to use food grade potassium hydroxide.

[Edited on 27-4-2014 by deltaH]

blogfast25 - 27-4-2014 at 01:39

Simply duplicating posts won't get you anywhere on this forum.

unionised - 27-4-2014 at 04:56

http://en.wikipedia.org/wiki/Synsepalum_dulcificum

Etaoin Shrdlu - 27-4-2014 at 06:36

Mobius, I can't think of any food-grade acids which aren't sour. Have you considered something like this? Or perhaps concentrating your anthocyanin solution, removing enough citric acid to hit pH 4 again, then adding that to carbonated water? That has a low pH but isn't overly sour.

I've never heard the term isotonic used to describe pH before. I thought it referred to those drinks that have a similar solute concentration to the human body.

EDIT: You might find this interesting. It looks like other people are curious about the same issue.

[Edited on 4-27-2014 by Etaoin Shrdlu]

nezza - 27-4-2014 at 10:00

If you want to change the taste try using miraculin or miracle berry fruit. You eat that and swill it around on your tongue and it changes the perception of sour and bitter. That is the stuff in the post above.

jwpa17 - 27-4-2014 at 14:20

One of the oldest definitions of an acid is something that turns blue litmus pink, reacts with active metals to give hydrogen, reacts with bases to make salt and water, and TASTES SOUR. It's inherent in the nature of aqueous acidic solutions to taste sour.
You can add sugars to add sweetness and make the sour less unappealing. You can add strong flavors (I suppose) and complement (or is that compliment) the sourness. But if it's acidic, it will taste sour. At least, as far as I know.
Seems to me you ought to bring the pH to 4 - which seems to be your magic number, for reasons I don't understand b/c the stomach is way more acidic, and neutral is less, even carbonated water is less, and isotonic has nothing to do with acidity insofar as I know - and acquire a taste for it. After all, you've added nutritional value with the calcium ions...
This isn't meant to be harsh. It's simply that "sour" and "acid" are tied together, as most elementary chemistry texts explain.

Etaoin Shrdlu - 27-4-2014 at 15:29

Apparently the hydronium ion is supposed to be what causes a "sour" taste. I did not know this. Good luck getting around that without tricking the taste buds.

pH 4 using citric acid is too tart for you, though? On reflection that doesn't sound bad to me. I think lemonade tends to be around 3. It is possible that this is more a function of the citric acid adding an objectionable flavor rather than a problem with acidity. Do you have other acids you could try at a similar pH and see if they are better?