PHILADELPHIA (July 8, 2009) -- 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 qual
|Contact: Leslie Stein|
Monell Chemical Senses Center