Author Topic: Methyl anthranilate (Grape Ester)  (Read 4950 times)

Offline ynotbrusum

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Re: Methyl anthranilate (Grape Ester)
« Reply #30 on: April 13, 2016, 01:52:32 AM »
I judged a recent Vienna and Marzen category with another judge and in two beers we both noticed the grape issue and I suspected Munich malt as the culprit.
Hodge Garage Brewing: "Brew with a glad heart!"

Offline Saccharomyces

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Re: Methyl anthranilate (Grape Ester)
« Reply #31 on: April 14, 2016, 04:11:47 AM »
As I explained to Martin yesterday, the conversion of heptanal to ethyl heptonoate requires multiple reactions.   The first reaction involves the conversion of the alkyl aldehyde heptanal to the higher alcohol heptanol (CH3(CH2)5CH2OH or C7H16O).  The conversion of heptanal to heptanol results in the production of the carboxylic acids heptanoic acid and 2-hydroxyheptanoic acid. Anyone who has read "Have You Seen Ester?" knows that a carboxylic acid is an acid whose formula ends in COOH, which is also known as a carboxyl group.



As one can clearly see, the formulas for heptanoic acid and 2-hydroxyheptanoic acid both end in COOH.


Ethyl heptanoate is the condensation reaction between ethanol and heptanoic acid.

C2H6O + CH3(CH2)5COOH → C9H18O2 + H2O

The above reaction reads one molecule of ethanol plus one molecule of heptanoic acid yields one molecule of ethyl heptanoate plus one molecule of water.

I have the links to the publications that I provided to Martin if anyone is interested.


Offline hopfenundmalz

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Re: Methyl anthranilate (Grape Ester)
« Reply #32 on: April 14, 2016, 04:53:20 AM »
As I explained to Martin yesterday, the conversion of heptanal to ethyl heptonoate requires multiple reactions.   The first reaction involves the conversion of the alkyl aldehyde heptanal to the higher alcohol heptanol (CH3(CH2)5CH2OH or C7H16O).  The conversion of heptanal to heptanol results in the production of the carboxylic acids heptanoic acid and 2-hydroxyheptanoic acid. Anyone who has read "Have You Seen Ester?" knows that a carboxylic acid is an acid whose formula ends in COOH, which is also known as a carboxyl group.



As one can clearly see, the formulas for heptanoic acid and 2-hydroxyheptanoic acid both end in COOH.


Ethyl heptanoate is the condensation reaction between ethanol and heptanoic acid.

C2H6O + CH3(CH2)5COOH → C9H18O2 + H2O

The above reaction reads one molecule of ethanol plus one molecule of heptanoic acid yields one molecule of ethyl heptanoate plus one molecule of water.

I have the links to the publications that I provided to Martin if anyone is interested.

Good to have some advanced knowledge laid on us!
Jeff Rankert
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BJCP National
Ann Arbor Brewers Guild
Home-brewing, not just a hobby, it is a lifestyle!

Offline narcout

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Re: Methyl anthranilate (Grape Ester)
« Reply #33 on: April 14, 2016, 04:58:38 AM »
I have the links to the publications that I provided to Martin if anyone is interested.

Cool. Please post.
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Offline klickitat jim

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Re: Methyl anthranilate (Grape Ester)
« Reply #34 on: April 14, 2016, 06:30:18 AM »
As I explained to Martin yesterday, the conversion of heptanal to ethyl heptonoate requires multiple reactions.   The first reaction involves the conversion of the alkyl aldehyde heptanal to the higher alcohol heptanol (CH3(CH2)5CH2OH or C7H16O).  The conversion of heptanal to heptanol results in the production of the carboxylic acids heptanoic acid and 2-hydroxyheptanoic acid. Anyone who has read "Have You Seen Ester?" knows that a carboxylic acid is an acid whose formula ends in COOH, which is also known as a carboxyl group.



As one can clearly see, the formulas for heptanoic acid and 2-hydroxyheptanoic acid both end in COOH.


Ethyl heptanoate is the condensation reaction between ethanol and heptanoic acid.

C2H6O + CH3(CH2)5COOH → C9H18O2 + H2O

The above reaction reads one molecule of ethanol plus one molecule of heptanoic acid yields one molecule of ethyl heptanoate plus one molecule of water.

I have the links to the publications that I provided to Martin if anyone is interested.
Howdy sir!

Offline jeffy

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Re: Methyl anthranilate (Grape Ester)
« Reply #35 on: April 14, 2016, 11:28:19 AM »
As I explained to Martin yesterday, the conversion of heptanal to ethyl heptonoate requires multiple reactions.   The first reaction involves the conversion of the alkyl aldehyde heptanal to the higher alcohol heptanol (CH3(CH2)5CH2OH or C7H16O).  The conversion of heptanal to heptanol results in the production of the carboxylic acids heptanoic acid and 2-hydroxyheptanoic acid. Anyone who has read "Have You Seen Ester?" knows that a carboxylic acid is an acid whose formula ends in COOH, which is also known as a carboxyl group.



As one can clearly see, the formulas for heptanoic acid and 2-hydroxyheptanoic acid both end in COOH.


Ethyl heptanoate is the condensation reaction between ethanol and heptanoic acid.

C2H6O + CH3(CH2)5COOH → C9H18O2 + H2O

The above reaction reads one molecule of ethanol plus one molecule of heptanoic acid yields one molecule of ethyl heptanoate plus one molecule of water.

I have the links to the publications that I provided to Martin if anyone is interested.
Howdy sir!
We missed you.
Jeff Gladish, Tampa (989.3, 175.1 Apparent Rennarian)
Homebrewing since 1990
AHA member since 1991, now a lifetime member
BJCP judge since 1995

Offline HoosierBrew

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Re: Methyl anthranilate (Grape Ester)
« Reply #36 on: April 14, 2016, 12:06:49 PM »
Welcome back!
Jon H.

Offline beersk

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Re: Methyl anthranilate (Grape Ester)
« Reply #37 on: April 14, 2016, 01:18:28 PM »
That's some crazy science-y sh*t! Welcome back!

Offline AmandaK

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Re: Methyl anthranilate (Grape Ester)
« Reply #38 on: April 14, 2016, 02:24:19 PM »
This has been fun and educational to read. I have experienced that flavor described as grape before, but had never associated it with actual grape flavor in my pallet.  I kind of think of the flavor as an under-fermented Pilsner malt flavor - kind of sour, but not really.  Nice to put a name and origin on it.

Totally agree. Thanks guys!
Amanda Burkemper
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Offline Saccharomyces

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Re: Methyl anthranilate (Grape Ester)
« Reply #39 on: April 16, 2016, 01:57:39 PM »
I have the links to the publications that I provided to Martin if anyone is interested.

Cool. Please post.


Bioconversion of heptanal to heptanol by Saccharomyces cerevisiae, http://onlinelibrary.wiley.com/doi/10.1002/yea.1750/pdf


Characterization of volatile aroma compounds in different brewing barley cultivars,
https://www.researchgate.net/publication/273755180_Characterization_of_volatile_aroma_compounds_in_different_brewing_barley_cultivars

Offline 69franx

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Re: Methyl anthranilate (Grape Ester)
« Reply #40 on: April 16, 2016, 02:46:32 PM »
All great info. Thanks saccharomyces
Frank L.
Fermenting: Ringler Pilsner (thanx Ron)
Conditioning: BVIP (thanx Denny)
In keg: Traquair House Clone (Skotrat style)
In the works:  Czech Dark Lager, American Pale Ale

RPIScotty

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Re: Methyl anthranilate (Grape Ester)
« Reply #41 on: April 16, 2016, 02:59:57 PM »
As I explained to Martin yesterday, the conversion of heptanal to ethyl heptonoate requires multiple reactions.   The first reaction involves the conversion of the alkyl aldehyde heptanal to the higher alcohol heptanol (CH3(CH2)5CH2OH or C7H16O).  The conversion of heptanal to heptanol results in the production of the carboxylic acids heptanoic acid and 2-hydroxyheptanoic acid. Anyone who has read "Have You Seen Ester?" knows that a carboxylic acid is an acid whose formula ends in COOH, which is also known as a carboxyl group.



As one can clearly see, the formulas for heptanoic acid and 2-hydroxyheptanoic acid both end in COOH.


Ethyl heptanoate is the condensation reaction between ethanol and heptanoic acid.

C2H6O + CH3(CH2)5COOH → C9H18O2 + H2O

The above reaction reads one molecule of ethanol plus one molecule of heptanoic acid yields one molecule of ethyl heptanoate plus one molecule of water.

I have the links to the publications that I provided to Martin if anyone is interested.

Glad to have you back.
« Last Edit: April 16, 2016, 03:01:52 PM by RPIScotty »

Offline ynotbrusum

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Re: Methyl anthranilate (Grape Ester)
« Reply #42 on: April 18, 2016, 10:15:48 PM »
It's so nice when knowledgeable people share information relating to a topic here.  Thanks, Mark!
Hodge Garage Brewing: "Brew with a glad heart!"

Offline brewinhard

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Re: Methyl anthranilate (Grape Ester)
« Reply #43 on: April 18, 2016, 10:40:50 PM »
It's so nice when knowledgeable people share information relating to a topic here.  Thanks, Mark!

And when it is freely offered without any smug replies.  Welcome back Mark!

Offline bucketbiochemist

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Re: Methyl anthranilate (Grape Ester)
« Reply #44 on: May 11, 2016, 04:06:24 AM »
I've had a "grape" flavor noted at the AHA comp. for Kolsch made with WLP029.  Do people think this is the same flavor?  Is WLP029 (or other Kolsch strains) known for this compound?