Umami
Umami (IPA: [uː mɑː mi]), popularly referred to as savoriness,[1][2][3][4][5] is one of the five basic tastes together with sweet, sour, bitter, and salty. Umami is a loanword from the Japanese umami (うま味) meaning "pleasent savory taste".[6] This particular writing was chosen by Professor Kikunae Ikeda from umai (うまい) "delicious" and mi (味) "taste". The Chinese characters 旨味 are used for a more general meaning, when a particular food is delicious.
Background
For a long time, scientists debated whether umami was indeed a basic taste; but in 1985 at the first Umami International Symposium in Hawaii, the term Umami was officially recognized as the scientific term to describe the taste of glutamates and nucleotides. [7] Now it is widely accepted as the fifth basic taste. Umami represents the taste of the amino acid L-glutamate and 5’-ribonucleotides such as guanosine monophosphate (GMP) and inosine monophosphate (IMP).[8] It is described as a pleasant "brothy" or "meaty" taste with a long lasting, mouthwatering and coating sensation over the tongue. This is due to the detection of the carboxylate anion of glutamate in specialized receptor cells present on the human and animal tongue.[9][10] Its fundamental effect is the ability to balance taste and round the total flavor of a dish. Umami clearly enhances the palatability of a wide variety of foods (for review Beauchamp, 2009).[11] Glutamate in acid form (Glutamic acid) imparts little umami taste; whereas the salts of glutamic acid, known as glutamates, can easily ionize and give the characteristic umami taste. GMP and IMP amplify the taste intensity of glutamate.[10][12]
Discovery of umami taste
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/fb/Kikunae_Ikeda.jpg/220px-Kikunae_Ikeda.jpg)
Glutamate has a long history in cooking.[13] Fermented fish sauces (garum), rich in glutamate, were already used in ancient Rome.[14] In the late 1800s, chef Auguste Escoffier, who opened what was the most glamorous, expensive, and revolutionary restaurant in Paris, created meals that tasted like no combination of salty, sour, sweet and bitter.[15] He had not, however, known the chemical source for this unique quality. Umami was not properly identified until 1908 by the scientist Kikunae Ikeda,[16] a Professor of the Tokyo Imperial University. He found that glutamate was responsible for the palatability of the broth from kombu seaweed. He noticed that the taste of kombu dashi was distinct from sweet, sour, bitter and salty and named it umami. Later, a disciple of professor Ikeda, Shintaro Kodama, discovered in 1913 that dried bonito flakes contained another umami substance [17]. This was the ribonucleotide IMP. In 1957, Akira Kuninaka realized that the ribonucleotide GMP present in shiitake mushrooms also conferred the umami taste. [18] One of Kuninaka's most important discoveries was the synergistic effect between ribonucleotides and glutamate. When foods rich in glutamate are combined with ingredients that have ribonucleotides, the resulting taste intensity is higher than the sum of both ingredients. This is why Japanese make dashi with kombu seaweed and dried bonito flakes, Chinese add Chinese leek and cabbage with chiken soup or Italians combine Parmesan cheese on tomato sauce with mushrooms. The umami taste sensation of those ingredients mixed together surpasses the taste of each one alone.
Properties of umami taste
Umami has a mild but lasting after taste difficult to describe. It induces salivation and a furriness sensation on the tongue, stimulating the throat, the roof and the back of the mouth (for review Yamaguchi, 1998). [19] [20] By itself, umami is not palatable, but it makes a great variety of foods pleasant especially in the presence of a matching aroma. [21] But like other basic tastes, with the exception of sucrose, umami is pleasant only when used within in a relatively narrow concentration range. [19]
Moreover, the optimum umami taste depends on the amount of salt and, at the same time, low-salt foods can maintain a satisfactory taste with the appropriate amount of umami. [22] In fact, Roinien et al. showed that ratings on pleasantness, taste intensity and ideal saltiness of low salt soups were greater when the soup contained umami, whereas low-salt soups without umami were less pleasant. [23]
Some population groups, such as the elderly, may benefit from umami taste because their taste and smell sensitivity is impaired by age and multiple medications. The loss of taste and smell can contribute to a poor nutritional status increasing their risk of disease.[24]
Experience umami taste by yourself
Bite a tomato and chew slowly 30 times, enjoying all tastes. What do you feel? Sweet? Sour? Do you percieve the flavors of tomato? With time, all the sweet, sour, or juices of tomato will dissapear. The remaining coating sensation on the tongue is umami.
Foods rich in umami
Many foods that we consume daily are rich in umami. Naturally occurring glutamate can be found in meats and vegetables; whereas inosinate comes primarily from meats and guanylate from vegetables. Thus, umami taste is common to foods that contain high levels of L-glutamate, IMP and GMP, most notably in fish, shellfish cured meats, vegetables (e.g. mushrooms, ripe tomatoes, Chinese cabbage, spinach, etc.) or green tea, and fermented and aged products (e.g. cheeses, shrimp pastes, soy sauce, etc.). Cite error: The <ref>
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We first encounter umami in breast milk.[25] It contains roughly the same amount of umami as broths.
There are some distinctions among stocks from different countries. Japanese dashi gives a very pure umami taste sensation because it is not based on meats. Dashi L-glutamate comes from sea kombu (Laminaria japonica) and inosinate from dried bonito flakes (katsuobushi) or small dried sardines (niboshi). In contrast, Western or Chinese broths have a more complex taste because of a wider mixture of amino acids from bones, meats and vegetables. For detail information on the specific content of umami substances in foods visit the The Umami Information Center.
Taste receptors
Biochemical studies have identified the taste receptors responsible for the sense of umami, a modified form of mGluR4, mGluR1 and taste receptor type 1 (T1R1 + T1R3).[26][27][28] The New York Academy of Sciences corroborated their acceptance stating that "Recent molecular biological studies have now identified strong candidates for umami receptors, including the heterodimer T1R1/T1R3, and truncated tye 1 and 4 metabotropic glutamate receptors missing most of the N-terminal extracellular domain (taste-mGluR4 and truncated-mGluR1) and brain-mGluR4 …The finding that human T1R1/T1R3 heterologously expressed in human embryonic kidney cells preferentially responds to glutamate, provides strong molecular evidence for specific umami detection in humans. However, these other receptors remain candidates and the role of each type of receptor in taste bud cells remains unclear."[9]
Umami tastes are initiated by these specialized receptors, with subsequent steps involving secretion of neurotransmitters including serotonin.[29] Other evidence indicates guanosine derivatives may interact with and boost the initial umami signal.[30]
Cells responding to umami taste stimuli do not possess typical synapses, but instead secrete the neurotransmitter ATP in a mechanism exciting sensory fibers that convey taste signals to the brain.
In monkey studies, most umami signals from taste buds excite neurons in the orbitofrontal cortex of the brain, showing spatially specific characteristics:[31]
- Single neurons having vigorous responses to sodium glutamate also respond to glutamic acid
- Some neurons display a mechanism of satiety.
The stomach can "taste" sodium glutamate using glumate receptors[32] and this information is passed to the lateral hypothalamus and limbic system in the brain as a palatability signal through the vagus nerve.[33]
Notes
- ^ "What exactly is umami?". The Umami Information Center.
- ^ "You say savory, I say umami".
- ^ Issie Lapowsky (9 February 2010). "Umami, savory 'fifth taste,' now available in a tube in grocery stores". NY Daily News. Retrieved 1 January 2011.
- ^ "Cambridge Advanced Learner's Dictionary". Cambridge University Press. Retrieved 1 January 2011.
- ^ "Merriam-Webster English Dictionary". Merriam-Webster, Incorporated. Retrieved 1 January 2011.
- ^ Jim Breen. "[[EDICT]]'s entry for umami". Retrieved 31 December 2010.
{{cite web}}
: URL–wikilink conflict (help) - ^ Y. Kawamura and M.R. Kare, ed. (1987). Umami: A basic taste,. New York,NJ: Marcel Dekker.
- ^ Yamaguchi S, Kumiko N (2000). "Umami and Food Palatability". Journal of Nutrition. 130 (4): 921S–26S. PMID 10736353.
{{cite journal}}
: Unknown parameter|month=
ignored (help) - ^ a b Thomas E. Finger, ed. (2009). International Symposium on Olfaction and Taste, Volume 1170. Hoboken,NJ: The Annals of the New York Academy of Sciences.
- ^ a b Chandrashekar J, Hoon MA, Ryba NJ, Zuker CS (2006). "The receptors and cells for mammalian taste". Nature. 444 (7117): 288–94. doi:10.1038/nature05401. PMID 17108952.
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ignored (help)CS1 maint: multiple names: authors list (link) - ^ Beauchamp G (2009). "Sensory and receptor responses to umami: an overview of pioneering work". Am J Clin Nutr. 90 (3): 723S–7S. PMID 19571221.
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ignored (help) - ^ Yasuo T, Kusuhara Y, Yasumatsu K, Ninomiya Y (2008). "Multiple receptor systems for glutamate detection in the taste organ". Biological & Pharmaceutical Bulletin. 31 (10): 1833–7. doi:10.1248/bpb.31.1833. PMID 18827337.
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ignored (help)CS1 maint: multiple names: authors list (link) - ^ Lehrer, Jonah (2007). Proust was a Neuroscientist. Mariner Books. doi:0908/1043570. ISBN 9780547085906.
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value (help) - ^ Smriga M, Mizukoshi T, Iwata D, Sachise E, Miyano H, Kimura T, Curtis R (2010). "Amino acids and minerals in ancient remnants of fish sauce (garum) sampled in the "Garum Shop" of Pompeii, Italy". Journal of Food Composition and Analysis. 23 (5): 442–446. doi:10.1016/j.jfca.2010.03.005.
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ignored (help)CS1 maint: multiple names: authors list (link) - ^ Sweet, Sour, Salty, Bitter ... and Umami, NPR
- ^ Ikeda K (2002). "New seasonings". Chemical Senses. 27 (9): 847–9. doi:10.1093/chemse/27.9.847. PMID 12438213.
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ignored (help) (partial translation of Ikeda, Kikunae (1909). "New Seasonings[japan.]". Journal of the Chemical Society of Tokyo. 30: 820–836.) - ^ Kodama S (1913). Journal of the Chemical Society of Japan. 34: 751.
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(help) - ^ Kuninaka A (1960). Journal of the Agricultural Chemical Society of Japan. 34: 487–492.
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(help) - ^ a b Yamaguchi S (1998). "Basic properties of umami and its effects on food flavor". Food Reviews International. 14 (2&3): 139–176.
- ^ Uneyama H, Kawai M, Sekine-Hayakawa Y, Torii K (2009). "Contribution of umami taste substances in human salivation during meal". Journal of Medical Investigation. 56 (supplement): 197–204. doi:10.2152/jmi.56.197. PMID 20224181.
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ignored (help)CS1 maint: multiple names: authors list (link) - ^ Edmund Rolls (2009). "Functional neuroimaging of umami taste: what makes umami pleasant?". The American Journal of Clinical Nutrition. 90 (supplement): 804S–813S. PMID 19571217.
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ignored (help) - ^ Yamaguchi S, Takahashi (1984). "Interactions of monosodium glutamate and sodium chloride on saltiness and palatability of a clear soup". Journal of Food Science. 49: 82–85.
- ^ Roininen K, Lahteenmaki K, Tuorila H (1996). "Effect of umami taste on pleasentness of low salt soups during repeated testing". Physiology & Behavior. 60 (3): 953–958. PMID 8873274.
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ignored (help)CS1 maint: multiple names: authors list (link) - ^ Yamamoto S, Tomoe M, Toyama K, Kawai M, Uneyama H (2009). "Can dietary supplementation of monosodium glutamate improve the health of the elderly?". Am J Clin Nutr. 90 (3): 844S–849S. doi:10.3945/ ajcn.2009.27462X. PMID 19571225.
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ignored (help)CS1 maint: multiple names: authors list (link) - ^ Agostini C, Carratu B, Riva E, Sanzini E (2000). "Free amino acid content in standard infant formulas: comparison with human milk". Journal of American College of Nutrition. 19 (4): 434–438. PMID 10963461.
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ignored (help)CS1 maint: multiple names: authors list (link) - ^ Chaudhari N, Landin AM, Roper SD (2000). "A metabotropic glutamate receptor variant functions as a taste receptor". Nature Neuroscience. 3 (2): 113–119. doi:10.1038/72053. PMID 10649565.
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: CS1 maint: multiple names: authors list (link) - ^ Nelson G, Chandrashekar J, Hoon MA; et al. (2002). "An amino-acid taste receptor". Nature. 416 (6877): 199–202. doi:10.1038/nature726. PMID 11894099.
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(help)CS1 maint: multiple names: authors list (link) - ^ San Gabriel A, Uneyama H, Yoshie S, Torii K (2005). "Cloning and characterization of a novel mGluR1 variant from vallate papillae that functions as a receptor for L-glutamate stimuli". Chem Senses. 30 (Suppl): i25–i26. doi:10.1093/chemse/bjh095. PMID 15738140.
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: CS1 maint: multiple names: authors list (link) - ^ Roper SD (2007). "Signal transduction and information processing in mammalian taste buds". Pflügers Archiv. 454 (5): 759–76. doi:10.1007/s00424-007-0247-x. PMID 17468883.
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ignored (help) - ^ Daniels, S (February 18, 2008). "Scientists develop new umami taste enhancers". FoodNavigator.com-Europe.
- ^ Rolls ET (2000). "The representation of umami taste in the taste cortex". The Journal of Nutrition. 130 (4S Suppl): 960S–5S. PMID 10736361.
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ignored (help) - ^ Uematsu, A; Tsurugizawa, T; Kondoh, T; Torii, K (2009). "Conditioned flavor preference learning by intragastric administration of L-glutamate in rats". Neuroscience letters. 451 (3): 190–3. doi:10.1016/j.neulet.2008.12.054. PMID 19146916.
- ^ Uematsu, A; Tsurugizawa, T; Uneyama, H; Torii, K. (2010). "Brain-gut communication via vagus nerve modulates conditioned flavor preference". Eur J Neurosci. 31 (6): 1136–43. doi:10.1111/j.1460-9568.2010.07136.x. PMID 20377626.
References
- Flavor Chemistry: Thirty Years of Progress By Roy Teranishi, Emily L. Wick, Irwin Hornstein; Article: Umami and Food Palatability, by Shizuko Yamaguchi and Kumiko Ninomiya. ISBN 0-306-46199-4
- Barbot, Pascal; Matsuhisa, Nobu; and Mikuni, Kiyomi. Foreword by Heston Blumenthal. Dashi and Umami: The Heart of Japanese Cuisine. London: Eat-Japan / Cross Media, 2009
External links
- Umami Information Centre (NPO)
- International Glutamate Information Service
- Italian umami research
- Discovery of Umami
- Discovery of Umami Receptors
- Society for Research on Umami Taste
- "Who's umami? Human taste now comes in five flavours", CBC News, June 1, 2007
- "Sweet, Sour, Salty, Bitter… and Umami" NPR, November 1, 2007
- A New Taste Sensation, by Katy McLaughlin, Wall Street Journal, 12/8/07.
- Mouthfuls : huitlacoche is another beispiel, 24/7/08.