Featured Research

from universities, journals, and other organizations

Sweet, Salty, Sour, Bitter And Umami: Variants Of 'Umami' Taste Receptor Contribute To Our Individualized Flavor Worlds

Date:
July 20, 2009
Source:
Monell Chemical Senses Center
Summary:
Using a combination of sensory, genetic, and in vitro approaches, researchers confirm that the T1R1-T1R3 taste receptor plays a role in human umami (amino acid) taste. They further report that variations in a gene that codes for this receptor correspond to individual differences in sensitivity to and perceived intensity of umami taste.

Umami is the taste quality associated with several amino acids, especially the amino acid L-glutamate. High levels of glutamate are present in many protein-rich foods, including meats and cheeses, in vegetables such as mushrooms, peas, and tomatoes, and in human breast milk.
Credit: iStockphoto/Liudmila Sundikova

Using a combination of sensory, genetic, and in vitro approaches, researchers from the Monell Center confirm that the T1R1-T1R3 taste receptor plays a role in human umami (amino acid) taste.

They further report that variations in the genes that code for this receptor correspond to individual variation in sensitivity to and perceived intensity of umami taste.

"These findings bolster our understanding of human taste variation and individual differences in tastes for essential nutrients," says senior author Paul A.S. Breslin PhD, a sensory geneticist at Monell.

Umami is the taste quality associated with several amino acids, especially the amino acid L-glutamate. High levels of glutamate are present in many protein-rich foods, including meats and cheeses, in vegetables such as mushrooms, peas, and tomatoes, and in human breast milk. Amino acids are the building blocks of protein, an essential macronutrient.

Commenting on clinical implications of the work, Breslin says, "Protein-energy malnutrition is one of the leading causes of death in children worldwide. Increased understanding of amino acid taste receptors may help nutritionists target the appetites of protein-malnourished children to provide good-tasting dietary supplements that kids will readily accept."

The findings, published online in the American Journal of Clinical Nutrition, strengthen the claim that umami is a fundamental human taste quality -- similar to sweet, salty, bitter and sour -- that indicates the presence of amino acids, peptides and related structures.

In the study, Breslin and his team first conducted sensory tests on 242 individuals, who were asked to discriminate the taste of weak L-glutamate from salt. Approximately 5% were unable to tell the two tastes apart, indicating that certain people are highly insensitive to umami and thus have difficulty detecting low levels of this taste quality.

An additional 87 individuals were asked to assess the intensity of glutamate's umami taste. The subjects tasted five concentrations of glutamate and rated the umami intensity of each on a scale that ranged from 'no sensation' to 'the strongest imaginable.'

The researchers next examined DNA from these 87 individuals to look for variations in the genes that code for T1R1 and T1R3, two protein subunits that combine to form the G-protein coupled receptor T1R1-T1R3. Comparing DNA structure to the glutamate taste responses of each individual, they found that variations (known as SNPs; single nucleotide polymorphisms) at three sites on the T1R3 gene were associated with increased sensitivity to glutamate taste.

A fourth set of studies used in vitro cell biology techniques to provide additional evidence that T1R1-T1R3 is a human amino acid taste receptor. When human T1R1-T1R3 receptors were expressed in a host cell line, these cells were able to respond specifically to L-glutamate.

Together, the findings demonstrate that the T1R1-T1R3 receptor significantly affects human sensitivity to umami taste from glutamate, and that individual differences in umami perception are due, at least in part, to coding variations in the T1R3 gene.

"We want to further understand the degree to which these genes account for umami taste perception," said Breslin. "This will in turn help in the discovery of other taste receptors that may play a role in umami taste and aid in our understanding of protein appetites."

He also speculates that because these same receptors are also found in the gastrointestinal tract, liver and pancreas, coding variation in the T1R3 gene may also influence how proteins and amino acids are processed metabolically.

Qing-Ying Chen, a postdoctoral fellow in Breslin's laboratory, is the paper's first author. Also contributing were Suzanne Alarcon, Anilet Tharp, Osama Ahmed, Nelsa Estrella, Tiffani Greene and Joseph Rucker. In addition to his faculty appointment at Monell, Breslin is Professor of Nutritional Sciences in the School of Environmental and Biological Sciences at Rutgers University. The research was funded by the National Institute on Deafness and Other Communication Disorders.


Story Source:

The above story is based on materials provided by Monell Chemical Senses Center. Note: Materials may be edited for content and length.


Cite This Page:

Monell Chemical Senses Center. "Sweet, Salty, Sour, Bitter And Umami: Variants Of 'Umami' Taste Receptor Contribute To Our Individualized Flavor Worlds." ScienceDaily. ScienceDaily, 20 July 2009. <www.sciencedaily.com/releases/2009/07/090708114754.htm>.
Monell Chemical Senses Center. (2009, July 20). Sweet, Salty, Sour, Bitter And Umami: Variants Of 'Umami' Taste Receptor Contribute To Our Individualized Flavor Worlds. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2009/07/090708114754.htm
Monell Chemical Senses Center. "Sweet, Salty, Sour, Bitter And Umami: Variants Of 'Umami' Taste Receptor Contribute To Our Individualized Flavor Worlds." ScienceDaily. www.sciencedaily.com/releases/2009/07/090708114754.htm (accessed August 22, 2014).

Share This




More Plants & Animals News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Farm Resurgence Grows With Younger Crowd

Farm Resurgence Grows With Younger Crowd

AP (Aug. 22, 2014) New England farms are seeing a surge in younger farm hands as the 'buy local' food movement grows across the country. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Drug Used To Treat 'Ebola's Cousin' Shows Promise

Drug Used To Treat 'Ebola's Cousin' Shows Promise

Newsy (Aug. 21, 2014) An experimental drug used to treat Marburg virus in rhesus monkeys could give new insight into a similar treatment for Ebola. Video provided by Newsy
Powered by NewsLook.com
Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Terrifying City-Dwelling Spiders Are Bigger And More Fertile

Newsy (Aug. 21, 2014) According to a new study, spiders that live in cities are bigger, fatter and multiply faster. Video provided by Newsy
Powered by NewsLook.com
Did Russia Really Find Plankton On The ISS? NASA Not So Sure

Did Russia Really Find Plankton On The ISS? NASA Not So Sure

Newsy (Aug. 21, 2014) Russian cosmonauts say they've found evidence of sea plankton on the International Space Station's windows. NASA is a little more skeptical. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins