Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Receptor activated exclusively by glutamate discovered on tongue

13.10.2009
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 to SINC.

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.

One hundred years ago, Kikunae Ikeda, a lecturer at the Imperial University of Tokyo, discovered the flavouring properties of glutamate after extracting it from the seaweed Laminaria japonica, calling its taste 'umami' (savoury). Since then, MSG has been one of the condiments that has received the most attention from researchers, along with its effects. All the international food safety agencies consider it safe for human consumption.

Regarding whether glutamate is possibly toxic, the researcher is categorical. "If food safety is evaluated with scientific rigor, MSG is entirely safe for human consumption. If people talk about it being toxic and MSG continues to receive negative publicity, it is because results are extrapolated from administration routes and doses that do not correspond to reality. In fact, it is less toxic than salt".

Even in breast milk

We are exposed to free glutamate from childhood. The most abundant amino acid in breast milk has 0.02% of glutamate, so a 5kg baby who takes 800 ml of breast milk a day, consumes 0.16g of glutamate. "The amount of glutamate consumed by babies that only breastfeed is equivalent to the MSG of Korea or Taiwan," the researcher concludes.

Total consumption of glutamate (both free and joined to proteins) in an adult diet amounts to around 10 grams a day (100-150mg/kg/day assuming a weight of 70kg), whereas the consumption of glutamate as a condiment in the form of MSG varies from 0.4g in the US, 1.5g in Japan and Korea and 3g in Taiwan (from 6 to 43mg/kg/day). MSG consumption in Spain has not been estimated, but the United Kingdom is calculated to consume 0.6 g on average and 2g in a minority segment of the population (three times more than average).

References:
Ana San Gabriel, Takami Maekawa, Hisayuki Uneyama, y Kunio Torii. "Metabotropic glutamate receptor type 1 in taste tissue". American Journal of Clinical Nutrition, 90(3):743S-746S, septiembre de 2009.

SINC | EurekAlert!
Further information:
http://www.plataformasinc.es

More articles from Life Sciences:

nachricht Antimicrobial substances identified in Komodo dragon blood
23.02.2017 | American Chemical Society

nachricht New Mechanisms of Gene Inactivation may prevent Aging and Cancer
23.02.2017 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>