Talk:Malic acid/Archive 1

Problems with molecular diagram
Hi JeLuf,

I saw your image for Malic acid, it is great except you have 3 bonds that are wrong, going from left to right on the structure, the second carbon has two vertical lines (one above, one below), there should be an 'H' on the end of these lines to denote hydrogen. A line without a symbol is implicitly stating it connects a Carbon atom- which is incorrect. Also the vertical bond on the 3rd backbone carbon also needs an 'H'. I hope this message is clear, it would be really easy on a white board :)

Thanks


 * I just checked with several of my chemistry books, and all of them use a line without a symbol for 'H', not for 'CH3'. Those are German books. Is this convention different between countries? -- JeLuF 17:34 11 Jun 2003 (UTC)


 * JeLuF - 2 things: 1) at least here in the US, the convention in a drawn chemical strucure is that a line with no symbol denotes a bond to Hydrogen atom - you had it right. 2) Does anybody out there have a Ka value for Malic Acid? You can e-mail it to tristanj@morebeer.com, I'd be much appreciative.    Tristan


 * Certainly in the UK, and I am pretty sure internationally, a line terminus on its own is considered to be a carbon atom in skeleton structures, NOT a hydrogen. See for example: http://www.chemguide.co.uk/basicorg/conventions/draw.html, a UK site (three quarters of way down page, "Skeletal formulae")

and here, this is an American page: http://pirate.shu.edu/~sowajohn/shortcourse/part1/part1.html see one third of the way down, "Drawing Organic Structures", '''each intersection and endpoint is a C. Carbon-carbon and carbon-heteroatom bonds are shown. The remaining valences on C are assumed to be H's.'''

and here, another US site: http://homepage.smc.edu/kline_peggy/Organic/Organic_Structures.html '''Line structures are used for both linear and cyclic structures. In these structures it is understood that there is a carbon atom at each "bend" and that each carbon atom is attached to as many hydrogen atoms as are needed to complete its valence of four.'''

and from Wikipedia itself: http://en.wikipedia.org/wiki/Structural_formula 143.252.80.110 18:10, 9 March 2006 (UTC)

Merging Malic Acid and Malate
I think this page should definitely be merged with Malate.Derekawesome 06:29, 21 September 2007 (UTC)


 * I agree, because to a biochemist, malate means malic acid. I would not recommend merging sodium malate and the parent acid.--Smokefoot 18:01, 21 September 2007 (UTC)

Requested addition
This page would be greatly enhanced with a list of other fruits and vegetables that are high in malic acid, apart from apples. OliAtlason (talk) 18:24, 2 March 2008 (UTC)

WikiProject Food and drink tagging
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Chemical burn?
The article currently states the following:

"These sweets are sometimes labeled with a warning that excessive consumption can cause irritation of the mouth."

Does anyone have any more information on this phenomenon? Furthermore, I would call it more than “irritation”. The last time I ate a sour candy (years ago; it was a lollipop of some sort, tasted like a piece of Warheads candy), I got a burn on the entire top of my tongue. It felt just like I had eaten or drunk something too hot. It took just as long as a burn from heat to heal, too. I'm assuming it was malic acid that did this. Can anyone relate or provide an explanation? Some good sources would provide for nice additions to the article. CTR -- Christopher C. Parker t c 15:24, 18 July 2008 (UTC)

Malic acid and mood
Malic acid would have a depressive effect if it increases the level of CO in the blood current thus decreasing blood pressure, which would add to the moody effect of some wines. I find no place to confirm this hypothesis. —Preceding unsigned comment added by 64.134.68.4 (talk) 01:47, 19 March 2010 (UTC)

Structure depiction and "Other names"
The chemical structure in the image has no stereochemistry, but the ball and stick representation indicates a particular enantiomer. Furthermore, the "Other names" section reflect contradictory stereochemical identifiers - these are not other names for compound without any indicated stereochemistry. -- The chemistds (talk) 16:36, 4 December 2010 (38S)

Effects of consumption of Malic acid
Can someone comment on the effects of consuming malic acid on human physiology. Kwgagel (talk) 18:38, 21 April 2011 (UTC)


 * Can't exactly comment but you might be able to witness the effects of the consumption by this video:

http://www.youtube.com/watch?v=MntJlNqufxM 82.44.87.78 (talk) 17:57, 30 August 2011 (UTC)

Malic acid "Teeth whitening"
I removed this section due to a disreputable source.


 * Malic acid can whiten teeth with baking soda but only when used sparingly (a few minutes every 3-4 months).

I am an expert in this field and was unable to find any supporting primary evidence for this claim.

Alpha hydroxy acid
Malic acid seems to be an Alpha hydroxy acid, is this true?--Mongreilf (talk) 15:22, 12 June 2012 (UTC)

Derivation and uses
A 2012 August 16 article in Food Business News on flavor enhancers implies that currently most commercially produced malic acid is derived from (petroleum) oil. The article also states "it also may be converted into other chemical derivatives used for a variety of plastic, polymer and resin products". Another use of malic acid (typically in the form of apples, apple cider, or lemon juice) is to soften gallstones (enabling the gall bladder to expel the softened gallstones through the bile ducts from whence they are excreted in feces).

This article would be greatly enhanced by more authoritative content on these points. Pegordon (talk) 17:04, 17 August 2012 (UTC)


 * Reading the article, I don't think they've commercialized the process yet. WP is not really a trade journal, let's wait for them to start selling this stuff before we talk about a fungal route to this compound. --Rifleman 82 (talk) 17:17, 17 August 2012 (UTC)

Isomers
This article uses all 3 conventions for isomers, L/D, R/S, +/- and doesn't indicate which corresponds to which. Someone needs to look at this. --Frank Lofaro Jr. (talk) 21:36, 27 November 2013 (UTC)

Natural occurence?
The article states that only L-malate occurs naturally. Whilst this is true for many L-sugars, I'm not sure this is the case for malate. E. coli has genes specifically for breaking down D-malate, and there's literature indicating that D-malate is produced naturally: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC202246/ I'm not an expert on the chemistry, only the microbiology, but I think a correction is needed. — Preceding unsigned comment added by 131.152.96.20 (talk) 09:49, 6 December 2013 (UTC)

Solubility in water
in the table on the left it is stated 558g/l - but on the linked reference i can not find these number. Taking chemspider (also linked in the table) - and there in properties - a solubility of 0,5 M is stated - which would be 67g/l if i did not calculate wrong. That would be a huge difference — Preceding unsigned comment added by 82.82.150.49 (talk) 15:24, 16 December 2013 (UTC)

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