Ever heard of kokumi? If not, you have certainly experienced it! Think of that full round taste that you get from some delicious piece of meat or cheese, or even onions and garlic—that’s kokumi!
As you may have gathered from the name, kokumi is a Japanese taste concept that has proven—like umami—to be very real. The kokumi sensation is accomplished by short protein-like compounds that have a γ-glutamyl group on the end of their amino acid chain. It’s not surprising, then, that these compounds are found in foods with protein, and that they enhance the savory umami taste of proteins.
By themselves, these compounds have little if any taste. But if you add a compound that confers kokumi to a sugar solution, it will taste sweeter, and to a salt solution, it will taste saltier!
Some foods with kokumi, from http://media.eurekalert.org/multimedia_prod/pub/web/19439_web.jpg
How do kokumi compounds do this magic?
As Kuroda and Miyamura have discovered,* these compounds increase calcium entry into taste cells (and trigeminal cells, too) by activating a calcium-sensing receptor. Normally, calcium enters these cells when their taste or trigeminal receptors are activated, leading to a taste signal. What the kokumi substances appear to do is to increase the amount of calcium that enters the cell, thus increasing the intensity of the signal, and prolonging the signal’s time of action, which means prolonged after-taste as well.
==>> And guess what…tea’s theanine, in chemistry parlance, is γ-glutamyl-L-ethylamide!
How delicious!
*Motonaka Kuroda and Naohiro Miyamura. Mechanism of the perception of “kokumi” substances and the sensory characteristics of the “kokumi” peptide, γ-Glu-Val-Gly. Flavour, 2015, 4:11
DOI: 10.1186/2044-7248-4-11.
Here’s a graph from this paper, showing the effects of the “kokumi” peptide on a low-fat custard:
No comments:
Post a Comment