Friday, March 13, 2009

The Taste of Gouda

 
Dutch Gouda cheese has a unique taste (pronounced HOW-dah in the Netherlands but Goo-dah everywhere else). Most of the chemicals that make up this unique taste have been identified. The bitter taste is due to CaCl2 and MgCl2 plus various peptides derived from incomplete digestion of milk protein. The sour taste is due to lactic acid and phosphates. The salty taste comes from sodium chloride, sodium phosphate and the amino acid L-arginine. Monosodium l-glutamate and sodium lactate contribute the umami taste. (The five tastes are sweet, salty, sour, bitter and umami.)

Combinations of all these compounds at the appropriate concentrations mimicked the taste of Gouda cheese but something was missing. The "mouthfulness," and the complexity of the mature cheese was not present in the artificial concoctions. The missing taste is called the kokumi sensation.

Theme
A Sense of Smell
Toelstede et al. (2009) have found the missing chemicals. They mostly consist of various γ-L-glutamyl dipetides such as γ-Glu-Glu, γ-Glu-Gly, γ-Glu-Gln, γ-Glu-Met, γ-Glu-Leu, and γ-Glu-His. The structure of γ-Glu-Glu is shown below.

Most people don't realize that peptides and amino acids can impart very powerful tastes. Monosodiun glutamate (MSG) is an obvious example. So is aspartame, a powerful sweetener that's a modified tripeptide (Asp-Phe-Ala methyl ester).

Isn't biochemistry wonderful?


Here's a tough question. Let's say you could identify, with absolute certainty, all the chemicals that make up the taste of Gouda cheese. Let's say you make them in a lab and mix them with tofu and get something that tastes exactly like Gouda cheese. Would there be some people who want to ban that artificial Gouda cheese because it has chemicals? Would those same people be happy to eat the "natural" cheese because it doesn't have chemicals?


Toelstede, S., Dunkel, A., and Hofmann. T. (2009) A Series of Kokumi Peptides Impart the Long-Lasting Mouthfulness of Matured Gouda Cheese. J. Agric. Food Chem., 2009, 57 (4), pp 1440–1448. [DOI: 10.1021/jf803376d]

11 comments :

  1. The synthetic gouda is going to be VERY expensive!

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  2. I'd never eat cheese because of all the chemicals in it - especially the high levels of hydrogen oxide.

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  3. Is kokumi different from the mouthfeel provided by tannins in red wine?

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  4. Well actually it's not so much what chemicals make up the Gouda, but in what proportions those chemicals are present. I'll assume you knew this and forgot to include it in the post. In this case, my skeptic frontal lobe would kick in and question the validity of the claim. Unless there would be similar reports in different laboratories and it is approved by Health Canada, I would not touch the synthetic stuff.

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  5. Why wouldn't one touch synthetic stuff? It's chemically indistinct from the normal stuff and they're just dipeptides. It's just ignorance of chemistry and a little protectionism, I think, that drives these objections-- it reminds me of food purity laws that prevent chemically-synthesized acetic acid from being used in food. The odd thing about objecting to simple dipeptides is that pretty much all our processed food has weird synthetic dyes or preservatives that one could be more legitimately concerned about.

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  6. Yeah. Biochemistry is indeed wonderful!
    Now a tough question:
    Is it possible to predict the taste based on the primary structure of an AA?

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  7. Living 10 minutes from Gouda, I wouldn't say that the Dutch pronounce it as 'HOW-dah', because there's no H, but a hard, throaty 'G', so maybe closer to 'GOW-dah'. Interesting article though.

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  8. If the actual texture was identical (tofu would not suffice), then I would have no problem eating the "artificial" Gouda. Assuming of course that there was price parity and variety (not all Goudas taste identical)

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  9. The germans and scottish have a sound similar to the dutch "G", but it is not found in the english language. It certainly doesn't sound like "H". Unless you don't mind a sore throat, I wouldn't try to pronounce it though :-)

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  10. Basically, what you're proposing is a sort of "cheese surimi". I think it might work...

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