Talk:Citric acid/Archive 1

HCA and Citric acid?
As Mr Mohamed Lotfy said in Nutrition I have heard that citric acid has some effect on lactose (or something) and therefore helps people feel rejuvenated after a long day....such as by squeezing and drinking the juice of 6 lemons, as one nutritionist recently mentioned here in Japan.

Is there a resource to find out about such claims.

Also, many commercial products marketed for obesity contain something called Hydroxy Citric Acid (HCA) which, as far as I can tell, is NOT the same as citric acid. The reason I ask is that soources such as Nutrition Action Healthleter say there is some fear of toxidity in animals, though not shown in people. Can someone comment on the relationship, if any, between HCA and Citric acid.

Thanks

Paul ARENSON

paul@arenson.org (not sure if I can find my way back here.....)


 * You may want to pose your question on Reference desk. Dysprosia 11:46, 3 Nov 2003 (UTC)

If you add a tag to the end of the properties table where is should be, it gets rendered in the HTML as & lt;/table& gt; so it displays " " when you visit the page if it's there. It is probably related to the odd placement of the following text paragraph in some browsers (like IE). HTML problem, or MediaWiki bug? Niteowlneils 05:43, 10 Mar 2004 (UTC)


 * I added the table, and so it was my markup that created the bug, and although I looked at things that might be wrong for an hour or so, I didn't find the source of the problem. I created the table from a copy-and-paste job from another page acetic acid, I think, where it worked fine, but I did some heavy customization on the table, and I may have messed something up in the process.  Ideally, I'd have a spreadsheet macro to generate the html from spreadsheet contents. Shimmin 10 Mar 2004


 * Yeah, I saw that. I also looked at the HTML for a while, including putting it thru the w3.org validator.  It found 3 errors, but correcting the seemingly most pertinent one didn't solve the problem.  The version of the table at boric acid also renders correctly.  It isn't really a big deal for this particular article, but since it may be evidence of a MediaWiki bug, I have enlisted the help of user_talk:bcorr, since I am not an HTML expert, and have only been a Wikipedian for a week or so.

Citric Acid is also a chelate in plants
Maybe that needs a sentence or two...

Addiction
An anonymous user (220.237.100.224) claimed that citric acid can be addictive. I removed that claim because I could find no evidence to support the claim on Google Scholar or on the web. It is, however, used to solubilize heroin before use, and is supplied in sachets to drug users in some enlightened countries. --Slashme 06:58, 16 November 2005 (UTC)

Info boxes
Is there any reason there are two infoboxes? It doesn't help that half of the information is duplicated (e.g. pKa values). IMacWin95 03:24, 29 May 2006 (UTC)

Systematic Name
The name in the info box doesn't seem to represent the molecule's structure adequately. The longest carbon chain is 5 atoms, so should the IUPAC name have pentane as the parent?

Two carboxylic acid groups on the ends of a single parent chain are normally included in the length of the chain, and the name should possess the suffix -dioic acid. For example, succinic acid is systematically named butanedioic acid, not ethane-1,2-dicarboxylic acid. But the third CO2H on citric acid is not on the parent chain, and -trioic acid is not acceptable, because an alkyl chain has only two ends. 82.13.150.91 23:32, 30 May 2006 (UTC)

The name in the box may not be the most correct IUPAC name, although it may be a possible name for citric acid. The suffix -carboxylic acid means there is a CO2H attached to the parent chain, and is not part of it. For example, the systematic name for benzoic acid is benzene carboxylic acid. Using this rule, citric acid could be 3-hydroxypentanedioic acid 3-carboxylic acid. —Keenan Pepper 15:28, 31 May 2006 (UTC)

Spectral Data Box
Is there really much point having the spectral data box, when UV/Vis, IR, NMR etc link to the wiki page for each of those types of spectra? Presumably it is only really of use if the links linked to the corresponding spectrum for the compound. Of course, I am not aware of a wikispectra site (what a good idea though), but NIST has spectra online for many compounds. tomohawk 10:51, 6 June 2006 (UTC)

Does Citric Acid cause Cancer???
As a kid in Spain, my father appeared one day with a list of additives by a "reputable" french hospital specializing in cancer research, that said that E330, citric acid, was the most cancerigenous of all!!!

As a kid this was a total pain as for a while everything that was bought in our house had their additives checked against this list. Today I have researched the matter through internet and to my surprise, it appears the list was false and that citric acid is indeed one of the safest additives.

The list I refer to has been referred as "The VILLEJUIF Hospital list" and it seems to be a clear example of bad press against citric acid. So far I have found 2 pages that expose this list, though they are in Spanish.

Please note that if my father 2500km away from the place managed to get his hands on it and torment my life, it shows that it has had wide social repercusion, atleast in Europe. This was further exacerbated when gradually some product labelling started to call additives by their chemical names instead of their corresponding code, i.e. they would say Citric Acid, instead of E330, and this was taken as definite proof by my parents that the list was right.

I would appreciate if we could find suitable references that definitely disprove the claims of said list and post it on the article so that young impresionable children in the future can drink their soft drinks and eat sweets in peace.Cgonzalezdelhoyo 10:20, 14 June 2006 (UTC)

It seems that the hospital made repeated claims that the list was not published by them. However even nowadays there are publications that make reference to such a list, though not as published by the Hospital, but rather as anecdotal reference of its presence in popular culture.


 * Cgonzalezdelhoyo, it's a good thing I've passed by the talk page before editing the article, since this is exactly what I was about to add. You'd be surprised to know that I had the same list hanging on our kitchen cupboard door here in Israel (and yes, it was in Hebrew!).


 * The site that I found then with a decent explanation still exists (www.ukfoodguide.net) and it seems there isn't any copyright limitation, so I'll go ahead and quote that into the article. Guycarmeli 00:20, 8 November 2006 (UTC)


 * I wrote an article on the leaflet of Villejuif. NerdyNSK (talk) 04:23, 4 September 2008 (UTC)


 * Citric Acid is normally produced by our body, and is present NATURALLY in food we eat. (gets its name from the fact that it's present in lemons). IT IS NOT CARCINOGENIC. The fact you're referring to, pheraphs, is that other compounds may be modified by the low pH of citric acid (eg. (eg. sodium benzoate to benzene, which is carcinogenic). But that's true for any acid. If a doctor tells you citric acid is carcinogenic, my advice would be to immediately get out of that hospital and not to get cured there, as they seem not to know basic biochemistry.

Are there any differences between natural and industrial citric acid???
Some people have told me that industrial processes produce 2 "flavours" of citric acid, one of which is the natural ocurring compound but not the second.Cgonzalezdelhoyo 10:48, 14 June 2006 (UTC)


 * No, citric acid is not enantiomeric. Shimmin 11:40, 14 June 2006 (UTC)


 * Citric acid is achiral. Maybe you were thinking of lactic acid or tartaric acid? —Keenan Pepper 00:37, 15 June 2006 (UTC)

Why is it important to inform the religion of the discoverer of the Citric acid in the Citric acid article?
Maybe there's some reason, and I don't know about it. Anyway, if there is indeed a good reason, it must be better explained in the article. If no one points out the reason, this information must be deleted because the religion of scientists has nothing to do with their scientific achievements A.Z. 09:07, 27 July 2006 (UTC)
 * I think it's important because it distinguishes the Islamic scientific tradition from that of the west. Looks like it's Iranian now though, which is probably just as good. cojoco (talk) 05:31, 15 March 2009 (UTC)

Toxic?
I ate the Acid (crystalised), is it dangerous?


 * Wikipedia is probably not the best place to ask for medical advice, for so many reasons! A quick look at an Oxford MSDS for citric acid revealed the following:


 * Toxicology
 * Severe eye irritant. Skin and respiratory irritant. Prolonged or repeated exposure may cause allergic reaction in some individuals.


 * If you ate some citric acid in crystalline form from a laboratory, it may have been contaminated with other, more poisonous compounds. The best thing to do would be to seek medical advice immediately, for example by phoning your doctor or going to the nearest hospital Emergency Department.


 * Hopefully you'll be OK.


 * Ben 16:11, 1 August 2006 (UTC).

On it's own it's quite harmless, in small amounts, at least. Infact, it's quite tasty. 88.110.193.60 (talk) 21:00, 18 December 2007 (UTC)

Softener regenerator vs cleaner
Saying that citric acid is used to regenerate the resin in water softeners is somewhat misleading, since regeneration usually means converting the resin back to the sodium form. Perhaps it's more appropriate to say that citric acid is used for cleaning.

Citric acid plus Metal
Just a quik question does anyone know what would happen were magnesium to react with citric acid?

<>

Similar thing that happen with any other acid plus metal I imagine. Magnesium + Citric Acid → Magnesium Citrate + Hydrogen   82.10.65.30 22:28, 2 October 2006 (UTC) 2HOOC—H2C—C(OH)(COOH)—CH2—COOH + Mg → Mg(OOC—H2C—C(OH)(COOH)—CH2—COOH)2 + H2↑...
 * I'm afraid magnesium is not a "metal I". Actually, it's a "metal II", and the equation goes would have gone
 * ...had solid magnesium and anhydrous acid powder been able to react, haha. And since the reaction takes place in solution, the magnesium needs to be in a soluble salt form, say nitrate in vitro and oxalate in vivo. Magnesium citrate is of course soluble as well because it is known to be present in milk: it serves as a source of highly assimilable magnesium therefrom. 92.101.8.2 (talk) 18:43, 10 October 2009 (UTC)

Citric acid on skin?
I know that Citric Acid allows the sun to penetrate hair because Citric Acid opens the cuticle; However, in looking at the effects when putting it on skin, it seems to be damaging. I was wondering if anyone could tell me what the cause is. An explaination for dummies would be better than a diagram, I'm only a Cosmotology student after all! :D

molecular formula vs empirical formula
C6H8O7 is the empirical formula for 2-hydroxy-1,2,3-carboxylpropane It would be better to use CH4OH(COOH)3 or CH5O(CO2H)3 Andreyvul 16:44, 7 December 2006 (UTC)

simple answer, no more complicated one, the molecular formulas you have proposed are chemically incorrect CH4 implies that there is a molecule of methane within the citric acid molecule which is impossible as for CH5 that its self is physically and chemically impossible in this dimension as carbon can only have a maximum of 4 covalent bonds plus there is only 4 carbons in the whole molecule which is a nice molecule but its not citric acid if you wanted the correct formula it would be  C3H4OH(CO2H)3 however this is not empirical formula as empirical formula just indicates the number of atoms of each element in the molecule enabling chemists to find the mass of the molecule using the atomic masses on the periodic table.

Hot
Anyone know if citric acid, when consumed as fruits or fruit juice, is never served hot? Does anyone have any info about that property that can be added to the page? CoolGuy 05:14, 29 January 2007 (UTC)

it becomes more acidic when heated because it is a week acid and is not fully dissosiated in water, therefore its probably more likley to be more sour. —Preceding unsigned comment added by 144.82.218.235 (talk) 22:04, 15 January 2008 (UTC)

effcect of citric acid 0n stainless steel 304 and 316
pls. advise effect of citric hot citric acid on stainless steel 304,316 and 316L —The preceding unsigned comment was added by 196.205.190.12 (talk) 10:19, 30 January 2007 (UTC).

pKa 3
The third pKa of citric acid is given by most reference sources as 6.40 not 5.40, there's probably a typo here! (check consensus by googling citric acid pK!) 86.7.26.71 10:48, 22 February 2007 (UTC) terry-s —Preceding unsigned comment added by 86.7.26.71 (talk) 22 Feb 2007 18:48


 * Seems right: citric+acid+pka3. I've made the change. --Rifleman 82 22:11, 22 February 2007 (UTC)
 * A lot of my pharmacy students titrate citric acid with a glass electrode to see titration curve and last pKa is always above 6.3 (and below 6.5)... —Preceding unsigned comment added by 131.220.136.22 (talk) 12:19, 30 June 2009 (UTC)

Citric Acid for use in Mold Remediation
There is currently a product available from Organic Products International that is marketed as a mold remediation product. It's active ingredient is listed as citric acid (5.1% concentration). The Wikipedia article indicates that Citric Acid has been used to grow Penicillium and Aspergillus Niger. A little contradiction here. Does anyone have any insight? Should this product be used to eliminate mold?? Tgibbs2000 15:02, 22 August 2007 (UTC)

the citric acid is produced by the Aspergillus Niger mold not the other way round. as for the question (mainly because i dont know) id like to second the query. does any one know if citric acid has anti fungal and anti bactireal properties? —Preceding unsigned comment added by 144.82.218.235 (talk) 22:45, 15 January 2008 (UTC)
 * It might, because, as you mentioned, both Penicillium and A. niger produce citric acid and therefore high concentrations of the acid in the medium suppress further metabolic activity, forcing the fungi to "hibernate" if not killing them. Likewise, yeasts are forced to stop fermentation by adding alcohol to the wort (in demi-sec etc. wine production). 91.122.102.124 (talk) 20:37, 10 October 2009 (UTC)

WikiProject class rating
This article was automatically assessed because at least one WikiProject had rated the article as start, and the rating on other projects was brought up to start class. BetacommandBot 07:52, 10 November 2007 (UTC)

WikiProject Food and drink Tagging
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Water softening
I removed the following parenthetical comment from the "water softening" section, as it contradicted the text already there. I agree that the existing description is not quite correct, but this is also not quite correct: the citric doesn't "clean" the resin, but I would have to read up on the exact mechanism to see whether the discussion of the valence number is correct, or whether it's a pH effect. Doesn't changing valence numbers imply oxidation or reduction? --Slashme (talk) 07:42, 1 August 2008 (UTC) (It does not regenerate the resin. It simply cleans it by changing the valence number of the metals attached to the resin, so that the sodium or potassium ions can effectively remove the metals, opening up more ion exchange sites on the resin bead. Also, phosphoric acid is more commonly used to accomplish this.)

Daily requirements?
As citric acid is such an important part of so many biological cycles, I would expect to see an average daily allowance, as there is with Vitamin C, or, if there is none, a statement about why this is so. cojoco (talk) 05:34, 15 March 2009 (UTC)

LOL, AFAIK it is routinely used as an "inert" material but see my comments below. The body makes it, citrate synthase, as needed. Nerdseeksblonde (talk) 20:58, 16 October 2009 (UTC)

Citric acid
Citric acid is sour —Preceding unsigned comment added by 208.101.147.6 (talk) 19:53, 18 April 2009 (UTC)

My experience with citric acid
My father used to own an ice cream parlour, and when making lemon sorbet would add citric acid to the mix, never understood why, as he used real lemon juice anyway. Well, being curious and a teenager I smelled the little tub of powder and noted that it smelled exactly like smegma. I later found myself in the back of the shop with a friend and gave him the tub, saying "what does this smell like to you?" and his response was: "By Jove, it smells of penis!", though not quite in the same words. Having read the article I'm now wondering if the analogy is due to the presence of an acid producing fungus on human skin. Maybe a note on the smell of citric acid could be added, though not mentioning my experience. Brutaldeluxe (talk) 17:21, 23 July 2009 (UTC)
 * Citric acid has no smell at all. Cacycle (talk) 01:43, 24 July 2009 (UTC)
 * Really? I guess it must have been some other compound then, it was in powder form so it must have been something that releases/turns to citric acid when in contact with water.Brutaldeluxe (talk) 01:52, 24 July 2009 (UTC)

medical uses
see my comments on vitamin-C page. It turns out that ( this is the OR part ) many medical effects thought to be due to ascorbate could be due to citrate. First, citrate is commonly used as a calcium chelating anti-coagulant and this itself may be counteract cancer related hypercalcemia ( my OR) but it has also been shown, putatively via Warburg effect, to be anti-cancer. See pubmed and also notice PFE's recent counterproductive drug trial that created hyperglycemia and possible killed more people than it helped ( which you could argue could have been fixed with more citrate consumption, again pure speculation not even qualified as OR but it an interested editor goes to pubmed you can find sources). Nerdseeksblonde (talk) 20:56, 16 October 2009 (UTC)

citric acid and diets.
How is citric acid important in our diets? —Preceding unsigned comment added by 69.255.91.218 (talk) 18:49, 2 March 2010 (UTC)

"Can be used for cherry packing."
This (non)sentence is the last in the "Food additive" section. What is it doing there? Please can it be turned into a more informative true sentence, or removed if it is vandalism? B0bGeezer (talk) 08:45, 15 June 2010 (UTC)
 * Without context it has no meaning, so I have removed it. -- Ed (Edgar181) 11:44, 15 June 2010 (UTC)

for merging...
...with Citrate? Vinne2 (talk) 19:23, 6 June 2010 (UTC)

I agree. —Preceding unsigned comment added by DforDave (talk • contribs) 02:48, 18 June 2010 (UTC)


 * No, I do not agree. The citrate anion is different from citric acid. The citrate anion is the conjugate base of many compounds, but not citric acid. Although it is related to citric acid, I think that they should not be merged. YOSF0113 (talk - contributions) 03:04, 2 October 2010 (UTC)

Precedent would suggest not merging. Look at oxalate or carbonate. These are articles separate from oxalic acid and carbonic acid. Oxalate is a good comparison because, like citrate, it can act as a chelator and form numerous compounds that way. There are also many ionic compounds of both oxalate and citrate. 142.103.207.10 (talk) 01:08, 19 November 2010 (UTC)

Illustration: major problem[s]
Sorry, but something is badly wrong with the biochemical cycle illustration. In the latest Opera browser, only a portion shows; tehrest is clipped. Clicking on the filename yields a tiny icon with minimal content.

Properties - deadly
Can someone explain the part about "Citric acid is the only acid to be deadly. a slightly stronger acid than other carboxylic acids..."? It makes no sense either chemically (as counterexamples, let me just mention prussic acid and cyanic acid) or grammatically and give the strong appearance of being vandalism. — Preceding unsigned comment added by Ptorquemada (talk • contribs) 22:09, 21 January 2011 (UTC)


 * Never mind, it was fortunately a recent vandalism, and I've fixed it. Ptorquemada (talk) 22:11, 21 January 2011 (UTC)

Citric Acid is also an exfoliant
JamesBowlin (talk) 22:31, 17 July 2011 (UTC)I believe that citric acid is also considered to be an alpha-hydroxy acid and is used in "gentle" chemical skin peels (in the form of lemon juice), much as is glycolic acid and lactic acid (sour milk). I'll cite the Wikipedia as a reference: http://en.wikipedia.org/wiki/Alpha_hydroxy_acid

Which one is correct? On the pka of citric acid
The main page says the pka of citric acid is 3.09. This page (http://en.wikipedia.org/wiki/Acid_dissociation_constant) says it is 3.18. Which one is correct? 無聲 (talk) 05:39, 24 August 2011 (UTC)

Untitled
pKa3 is listed as having values of 5.4, 6.39, and 6.4. The 5.4 reference is from Data for Biochemical Research, 1958 and is almost certainly wrong. In fact the 6.39 pKa apparently comes from Data for Biochemical Research, 1986. Sigma and other reputable sources typically report 6.4. If no one objects I'll change it to simply 6.4. Scouras (talk) 02:54, 31 January 2012 (UTC)

129.237.6.61 (talk) 13:37, 20 April 2012 (UTC)Laird The correct pKa is 5.4. Citric acid's pKa was misprinted as 6.4 in the CRC handbook some years ago, and the mistake has propagated throughout literature.

= Citric acid burns ===

I realise that 1st hand experience is rarely credited, but upon contact with my arms (for less than 10 minutes) citric acid in lime juice gave me minor acid burns - resulting in blistering, redness, pain etc. worse than 1st degree sunburn. This has also resulted in consequent photosensitivity due to pigmentation damage. I think that there should be some inclusion of the potential for such chemical burns upon contact with 'sensitive skin'. —Preceding unsigned comment added by 202.172.103.110 (talk) 11:48, 8 February 2011 (UTC)

Citric acid can certainly cause burns. A 1M solution is around pH 1.5. Scouras (talk) 02:54, 31 January 2012 (UTC)

Whoever maintains this article - please look into adding this info from National Institute of Health: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2259267/ Apparently, citric acid causes cancer! — Preceding unsigned comment added by Aleksandrc (talk • contribs) 03:59, 2 March 2011 (UTC)

= Citric acid in manufacturing explosives ===

This is clearly stupid. I dont think someone can really make much of a so unstable material and also citric acid is everywhere and you cant raise suspicion about it...furthermore sulfuric acid is better in production of the explosive — Preceding unsigned comment added by 88.218.192.235 (talk) 17:34, 21 August 2011 (UTC)

= Ascorbic acid? ===

Why does the Other Methods section talk about ascorbic acid? — Preceding unsigned comment added by 174.127.161.10 (talk) 21:00, 23 January 2012 (UTC)

Typo in Occurance -section?
"The concentrations of citric acid in citrus fruits range from 0.005 mol/L for oranges and grapefruits to 0.30 mol/L in lemons and limes"

The 0.005 mol/L seems too low to me, could that be an error? (could be 0.05 mol/L =0.30/6 if that number is also pulled from citation 10 (the conclusions section)).

See also http://web.archive.org/web/20060826064558/http://www.britishsoftdrinks.com/htm/qa/AdditivesIngredients/acids/acids.htm (referenced from orange juice article) - acid content is around 1% (10 g/L ~ 0.05 mol/L). also http://www.plantphysiol.org/content/20/1/3.full.pdf (just googled "orange juice citric acid content") indicates that citric acid content is around 8-25 g/L (see summary at the end)

Sorry, I rather don't edit the article myself, as I'm not really familiar with the etiquette.

Citric Acid Passivation
Can someone please tell me how to test the concentration of citric acid ,& at what is the best strength for passivation? — Preceding unsigned comment added by 176.24.164.62 (talk) 14:57, 16 November 2013 (UTC)

citric acid Extracellular/Intracellular?
citric acid is a extracellular product or intracellular? thanks --84.108.213.48 (talk) 19:02, 23 February 2014 (UTC)

Citric Acid pKa
Citric (lemons),Malic(apples),Tartaric(grapes),Lactic(yogurt),Acetic(vinegar). — Preceding unsigned comment added by 59.88.40.84 (talk) 09:36, 28 October 2013 (UTC)

Gerber
"The discovery of citric acid has been credited to the 8th century alchemist Jābir ibn Hayyān (Geber)."

I have removed the above, as unreliably sourced. The article cited is about tartaric acid, and the reference to citric acid is a throw away line "Aside from tartaric acid, he discovered citric acid and acetic acid, as well as hydrochloric acid and nitric acid which he mixed to obtain aqua regia, king's water." However we know that at least "hydrochloric acid and nitric acid which he mixed to obtain aqua regia" are attributed to pseudo-Gerber, so we cannot trust this source to distinguish between Gerber and pseudo-Gerber, we need a new source, therefore.

All the best, Rich Farmbrough, 23:06, 7 April 2014 (UTC).

pH levels in table
I think the table of pH levels at different molarities was wrong. It showed 0.1M-->	pH=2.57

0.5M-->	pH=1.72

1-->pH=1.57

I wanted to use these values to check some calculations I did for a homebrew project and couldn't get the correct value at 0.1M. I then used an online calculator at http://www.endmemo.com/chem/phcal.php, and it got the same values I got across the spectrum.

I'm gonna assume that the calculator and my own calculations are correct, and change the pH value at 0.1M to 2.08.

(I do not know what assumptions the calculator is based on; my own calculations are done using all three pKa values and a numerical spreadsheet solution.)

Dr bab (talk) 05:55, 8 July 2015 (UTC)

Does lemon OIL have Citric Acid and if yes, what is the pH of Lemon OIL?
ee1518 (talk) 18:03, 2 September 2015 (UTC)

Solubility in water
The listed values 117.43 g/100 mL (10 °C), 147.76 g/100 mL (20 °C), 180.89 g/100 mL (30 °C), 220.19 g/100 mL (40 °C), 382.48 g/100 mL (80 °C), 547.79 g/100 mL (100 °C) are not in the cited article.

The PubChem article lists the mass fraction for the solubility Solubility in water: 54.0% w/w at 10 deg C; 59.2% at 20 deg C; 64.3% at 30 deg C; 68.6% at 40 deg C; 70.9% at 50 deg C; 73.5% at 60 deg C; 76.2% at 70 deg C; 78.8% at 80 deg C; 81.4% at 90 deg C; 84.0% at 100 deg C O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 416

If you converte the mass fractions back to soluble mass per 100 ml solvant you get different results, that differ more than 5%.

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Solubility in water
The listed values 117.43 g/100 mL (10 °C), 147.76 g/100 mL (20 °C), 180.89 g/100 mL (30 °C), 220.19 g/100 mL (40 °C), 382.48 g/100 mL (80 °C), 547.79 g/100 mL (100 °C) are not in the cited article.

The PubChem article lists the mass fraction for the solubility Solubility in water: 54.0% w/w at 10 deg C; 59.2% at 20 deg C; 64.3% at 30 deg C; 68.6% at 40 deg C; 70.9% at 50 deg C; 73.5% at 60 deg C; 76.2% at 70 deg C; 78.8% at 80 deg C; 81.4% at 90 deg C; 84.0% at 100 deg C O'Neil, M.J. (ed.). The Merck Index - An Encyclopedia of Chemicals, Drugs, and Biologicals. Cambridge, UK: Royal Society of Chemistry, 2013., p. 416

If you converte the mass fractions back to soluble mass per 100 ml solvant you get different results, that differ more than 5%.

Uses of citrate groups
Since citrate redirects here perhaps we could say why many mineral supplements and some drugs are available in citrate form; presumably to improve solubility and gut absorption and bioavailability ? Could compare with gluconate ? - Rod57 (talk) 13:25, 20 December 2017 (UTC)

Word(s) missing -- "cycles of"?
"After tens of thousand[s] of [???] evolution in a minimal glucose medium that also contains citrate ..." — Preceding unsigned comment added by 188.103.167.3 (talk) 14:10, 22 January 2018 (UTC)

pKa values?
There are two different and inconsistent sets of pKa values for citric acid - one set in the sidebar, the other in text. Could someone resolve the discrepancy?

Categories listed for citric acid
Why is citric acid included in Category:Aldols but not in Category:Beta hydroxy acids? According to the article on aldols, only aldehydes and ketones should be considered as such and citric acid does not contain either of those functional groups. On the other hand, it is clearly a beta hydroxy acid. If no-one objects, I'll make these changes to the main article Michael D. Turnbull (talk) 14:59, 7 April 2020 (UTC) ✅ Made these changes Michael D. Turnbull (talk) 13:20, 9 April 2020 (UTC)

Relocate or reduce paragraph about "MCA" and inflammation from the lead section?
I have some concerns about the paragraph in the lead section which talks about "manufacturated citric acid" and a supposed link to various inflammatory conditions. It takes up about half of the lead section explaining and justifying the conclusions of an article which turns out to have been based on only four case studies. It also seems to misrepresent the reported clinical prevalence, even as presented in the cited article. I cannot speak to the support this hypothesis may have from the scientific and clinical communities, but it is undoubtedly far enough from scientific consensus that the lead section is likely not the best place for it.

While I am not comfortable removing it in its entirety on account of my own lack of expertise on the matter, I propose that it be reduced to something along the lines of:

"An article published in 2018 presented four case reports of patients experiencing various inflammatory symptoms, which the authors believe may have been caused by ingestion of Aspergillus-derived citric acid used as a food additive."

and placed under a different section, at least until someone more knowledgable on the topic than myself can weigh in. As I am very green when it comes to this kind of edit, I welcome hearing from others before I go ahead with such a change. PiersR97 (talk) 12:38, 21 May 2023 (UTC)


 * @PiersR97 The citation being quoted does not pass our stringent requirements for medical claims, summarised at WP:MEDRS, since it is a single primary report based on just four individuals. Also, it is not appropriate to cover in the WP:LEAD of an article something that is not mentioned elsewhere in the body, since the lead should be a simple summary of the whole article. I'm therefore going to revert that addition and await anyone else's comment here as to why it should be included somewhere, as in the policy at WP:ONUS. Mike Turnbull (talk) 13:05, 21 May 2023 (UTC)
 * Thanks, I had a feeling that it ought to be removed but wasn't confident in reverting it myself since I've never done anything but spelling corrections and obvious vandalism reversions before. I see now that my proposed changes would've just moved the problem around, if not made it worse. Sorry, I'll try to read up on the relevant guidelines if I come across something like this again. PiersR97 (talk) 13:37, 21 May 2023 (UTC)