Thaum xyoo pua 20th, Kikunae Ikeda xav ntau heev txog kua zaub. Ib tug Japanese chemist kawm ib tug seaweed thiab qhuav ntses flake broth hu ua dashi. Dashi muaj qhov tshwj xeeb saj. Ikeda sim cais cov molecules tom qab nws cov saj txawv. Nws paub tseeb tias muaj qee qhov kev sib txuas ntawm cov duab ntawm lub molecule thiab kev xaav ntawm saj uas nws tsim nyob rau hauv tib neeg. Nws thiaj li, Ikeda muaj peev xwm cais ib qho tseem ceeb saj molecule los ntawm seaweed nyob rau hauv dashi, glutamic acid. Hauv xyoo 1909, Ikeda tau hais tias qhov kev xav zoo siab uas tau tshwm sim los ntawm glutamate yuav tsum yog ib qho ntawm cov nyiam nyiam. Nws hu ua "umami", uas txhais tau tias "qab" hauv Japanese.
Tab sis ntev dhau los, nws qhov kev tshawb pom tsis tau lees paub. Ua ntej, Ikeda txoj haujlwm tseem nyob hauv Nyij Pooj mus txog thaum kawg tau muab txhais ua lus Askiv hauv xyoo 2002. Qhov thib ob, qhov saj ntawm umami yog qhov nyuaj rau cais tawm ntawm lwm tus. Nws tsis tau ntau dua thiab meej dua los ntawm kev ntxiv glutamate, ib yam li cov khoom qab zib, qhov twg koj tuaj yeem ntxiv qab zib thiab saj qhov qab zib. “Cov no yog txawv kiag li saj. Yog tias cov khoom qab zib no tuaj yeem muab piv rau xim, ces umami yuav daj thiab qab zib yuav liab, "Ikeda sau tseg hauv nws tsab xov xwm. Umami muaj ib qho me me tab sis lingering aftertaste txuam nrog salivation. Umami nws tus kheej tsis saj zoo, tab sis nws ua rau ntau yam tais diav txaus nyiam.
Ntau tshaj li ib puas xyoo tau dhau mus. Cov kws tshawb fawb thoob plaws ntiaj teb tam sim no lees paub tias umami yog qhov tseeb thiab tsuas yog cov tsw qab zoo li lwm tus. Qee cov neeg tau hais tias tej zaum umami tsuas yog hom salinity xwb. Tab sis yog tias koj saib ze ntawm cov hlab ntsha uas xa cov lus los ntawm koj lub qhov ncauj mus rau koj lub hlwb, koj tuaj yeem pom tias umami thiab qab ntsev ua haujlwm los ntawm ntau txoj kev.
Ntau qhov kev lees paub ntawm Ikeda cov tswv yim tuaj txog 20 xyoo dhau los. Tom qab tshwj xeeb receptors tau pom nyob rau hauv lub saj buds uas nqus cov amino acids. Ntau pawg tshawb fawb tau tshaj tawm cov receptors tshwj xeeb rau glutamate thiab lwm yam umami molecules uas tsim kom muaj kev sib koom ua ke.
Ib txoj hauv kev, nws tsis yog qhov xav tsis thoob tias peb lub cev tau hloov kho txoj hauv kev kom nkag siab txog qhov muaj cov amino acids, vim lawv tseem ceeb heev rau peb txoj sia. Tib neeg cov kua mis muaj qib ntawm glutamate uas yog hais txog tib yam li dashi broth uas Ikeda tau kawm, yog li peb tau paub txog qhov saj.
Ikeda, rau nws ib feem, nrhiav tau lub chaw tsim khoom txuj lom thiab pib tsim nws tus kheej kab ntawm umami txuj lom. Nws yog monosodium glutamate, uas tseem tsim hnub no.
Puas muaj lwm yam tsw?
Ib zaj dab neeg nrog lub siab yuav ua rau koj xav paub yog tias muaj lwm yam tseem ceeb uas peb tsuas yog tsis paub txog? Qee cov kws tshawb fawb ntseeg tias peb yuav muaj qhov thib rau qhov saj uas cuam tshuam nrog rog. Muaj ntau ntau tus neeg sib tw zoo rau cov rog rog ntawm tus nplaig, thiab nws yog qhov tseeb tias lub cev muaj zog heev rau cov rog hauv cov zaub mov. Txawm li cas los xij, los ntawm lub sijhawm cov roj ntau txaus uas peb tuaj yeem saj lawv, peb tsis nyiam saj.
Txawm li cas los xij, muaj lwm tus neeg sib tw rau lub npe ntawm kev saj tshiab. Cov kws tshawb fawb Nyij Pooj tau qhia lub tswv yim ntawm "kokumi" rau lub ntiaj teb. "Kokumi txhais tau hais tias qhov saj uas tsis tuaj yeem qhia los ntawm tsib qhov kev xav tau yooj yim, thiab tseem suav nrog cov saj nyob deb ntawm lub ntsiab saj xws li thickness, fullness, continuity, and harmony," lub website Umami Information Center hais. Ua los ntawm trio ntawm cov amino acids sib txuas, qhov kev xav ntawm kokumi ntxiv rau kev lom zem ntawm qee yam khoom noj, feem ntau yog unsweetened.
Harold McGee, tus kws sau zaub mov, muaj lub sijhawm los ua piv txwv qee qhov ntawm kokumi-inducing lws suav sauce thiab cheese flavoured qos yaj ywm chips ntawm lub 2008 Umami Summit hauv San Francisco. Nws tau piav qhia txog qhov kev paub dhau los: "Cov khoom qab zib zoo li nce siab thiab sib npaug, zoo li yog lub ntim tswj thiab EQ nyob rau. Lawv kuj zoo li qee zaum tuav kuv lub qhov ncauj - Kuv hnov nws - thiab kav ntev dua ua ntej ploj mus.