"Umami" Receptor Discovered.

[Darryl Shaw]

Scientists have been arguing over the whole umami thing for years but it looks like they've finally found specific taste receptors for savoury foods. One thing that concerns me about this story though is the research was conducted at the Institute of Life Sciences in Ajinomoto Japan and they don't make it clear whether or not this organisation has any links with Ajinomoto Inc which as I'm sure everyone knows is Japans largest manufacturer of msg.

Receptor Activated Exclusively By Glutamate Discovered On Tongue.

ScienceDaily (Oct. 10, 2009) — One hundred years ago, Kikunae Ikeda discovered the flavour-giving properties of glutamate, a non essential amino acid traditionally used to enhance the taste of many fermented or ripe foods, such as ripe tomatoes or cheese. New research now reveals that the tongue has a receptor that is exclusively activated by glutamate.

"Although other receptors have been found on the tongue that are also aroused by glutamate, they are not specific. That is, they need to be in contact with nucleotides and many other amino acids to be activated. Our study reveals the first receptor on the tongue exclusively for glutamate," Ana San Gabriel, the main author of the article and a scientist belonging to the Spanish Network of Researchers Abroad, based at the Institute of Life Sciences in Ajinomoto, Kawasaki (Japan), explained.

According to the study, which was published in the latest issue of the American Journal of Clinical Nutrition, glutamate is a non-essential amino acid that is used commercially as glutamate sodium salt, monosodium glutamate (MSG) E-621, because it is stable and easy to dissolve. This added glutamate, identical to the 'natural glutamate', is sometimes used to reduce cooking and meal preparation time and to provide more flavour.

MSG is also used to reduce the sodium in meals: table salt contains 40% sodium, whereas MSG contains 13%. Many fermented or ripe foods are rich in natural MSG, such as ripe tomatoes (250-300 mg/100g), parmesan cheese (1600 mg/100g), Roquefort cheese (1600 mg/100g) and Gouda cheese (580 mg/100g). Manchego cheese and Iberian cured ham have a similar taste.

http://www.sciencedaily.com/releases...1009092344.htm

[John Wood1]

An interesting read. We discussed umami receptors when I was taking Human A&P in college, and I wasn't aware that there was any controversy concerning their existence.

Our book identified umami as a receptor for savory (read, meat) flavors by responding to the presence of amino acids and did not mention any specific amino acid. I would have to assume that this meant that the receptor responded to nitrogen, but that's just a guess.

I'm curious about this statement that umami responds specifically and solely to glutamate, especially considering that it is a non-essential amino acid. My book is in my office at the gym, I'll look tomorrow and see if it gives any reference.