Kev kho yog cov txheej txheem tseem ceeb hauv kev tsim tshuaj yej ntsuab. Qhov tseem ceeb, qhov kub thiab txias sai sai inactivate oxidases nyob rau hauv cov tshuaj yej nplooj kom tsis txhob oxidation ntawm catechins, khaws cia ntsuab tshuaj yej lub npe cawv ntsuab thiab ntsuab nplooj zoo li thaum xauv rau hauv nws cov tshiab, brisk tsw.
Steamed fixing cia siab rau cov cua kub ntub, thaum lub lauj kaub -kib kho siv cov cua sov qhuav los ntawm dov nruas. Txawm hais tias qhov sib txawv tsuas yog nyob rau hauv qhov chaw tshav kub, ob txoj kev rov kho cov tshuaj muaj pes tsawg leeg ntawm cov tshuaj yej nplooj ntawm qib molecular.
Tsis ntev los no, ib pab neeg tshawb fawb los ntawm Sichuan University tau luam tawm ib daim ntawv hu ua Differential Characteristics and Mechanisms of Green Tea Processed by Different Fixing Technologies in the Journal of Food Science. Kev tsom mus rau me me - thiab - cov nplooj ntoo nruab nrab cov tshuaj yej cultivars nyob rau hauv Sichuan, txoj kev tshawb no qhia txog qhov tsis zoo ntawm cov tshuaj yej ntsuab nyob rau hauv cov txheej txheem kho txawv los ntawm kev tshawb nrhiav kom muaj nuj nqis, kev tshuaj ntsuam metabolomic thiab lwm yam kev tshuaj xyuas.
1. Steamed ntsuab yog txawm ntsuab
Cov neeg uas feem ntau haus dej tshuaj yej ntsuab yuav tsum tau hnov txog cov lus "steamed ntsuab" thiab "do kib ntsuab".
Ntau tus neeg xav tias ob qho tib si tsuas yog cov cua kub sib txawv, ib qho siv chav thiab lwm yam siv lub lauj kaub rau kib,
Qhov tseeb, muaj qhov sib txawv ntawm ob qho tib si ntawm cov kua zaub xim, aroma, saj, thiab muaj pes tsawg leeg ntawm ntau pua cov khoom muaj.
Daim duab 1 Qhov txawv ntawm qhov ci, ntsuab, thiab daj ntawm cov tshuaj yej ntsuab nrog cov txheej txheem sib txawv
Ua ntej, pom kev, cov tshuaj yej qhuav, tshuaj yej kua zaub, thiab nplooj hauv paus ntawm steamed ntsuab tshuaj yej yog feem ntau ntsuab thiab ntau vibrant.
Qhov no yog vim tias qhov chaw ntub dej thiab kub ntawm chav ua kom qhuav muaj qhov qis dua ntawm kev puas tsuaj rau chlorophyll piv rau qhuav thiab kub nruas roasting, uas tuaj yeem khaws cov xim ntsuab ntawm cov tshuaj yej nplooj.
Txawm li cas los xij, tsoos nruas frying nrog qhov kub thiab txias ib puag ncig tuaj yeem ua rau qee qhov kev puas tsuaj ntawm chlorophyll, ua rau cov kua zaub ntau dua rau cov xim daj thiab ci.
2.Stir kib ntsuab muaj ib tug nplua nuj thiab nplua nuj aroma, thaum steamed ntsuab yog tshiab thiab elegant
Aroma yog qhov yooj yim tshaj plaws pom qhov sib txawv ntawm ob hom tshuaj yej ntsuab.
Txoj kev tshawb no tau tshawb pom tag nrho ntawm 157 cov tshuaj tsw qab tsis zoo, suav nrog xya pawg loj xws li ketones, aldehydes, cawv, esters, thiab hydrocarbons. Cov aroma muaj pes tsawg leeg thiab cov ntsiab lus ntawm cov txheej txheem sib txawv tau pom qhov sib txawv tseem ceeb.
Daim duab 2 Qhov sib txawv ntawm cov ntsiab lus ntawm cov tshuaj yej ntsuab nrog cov txheej txheem sib txawv
Qhov kub thiab qhuav ntawm do frying tuaj yeem ua kom muaj kev hloov pauv aroma hauv cov tshuaj yej nplooj: Maillard cov tshuaj tiv thaiv ua rau hlawv thiab cov txiv ntseej aroma tshuaj, carotenoids degrade los tsim cov paj thiab txiv hmab txiv ntoo aroma, thiab glycosidic hydrolysis tso tawm cov tshuaj tsw qab dawb.
Kev sim cov ntaub ntawv qhia tau hais tias qhov kev faib ua feem ntawm cawv aroma tshuaj nyob rau hauv tag nrho cov volatile tebchaw ntawm nruas kib ntsuab mus txog 40.23%;
Cov txheej txheem sib xyaw ua ke nrog lub nruas cua sov cua muaj tag nrho cov ntsiab lus cawv ntawm 2.12mg / kg, ntawm cov khoom siv paj yeeb linalool muaj cov ntsiab lus ntawm 1.42mg / kg. D- cov ntsiab lus limonene, uas ua rau citrus qab zib, kuj yog qhov siab tshaj plaws, thiab cov paj tsw qab yog cov nplua nuj thiab muaj zog tshaj plaws.
Daim duab 3 Qhov sib txawv ntawm qhov kev faib ua feem ntawm cov tshuaj tsw qab hauv cov tshuaj yej ntsuab nrog cov txheej txheem sib txawv
Nyob rau hauv sib piv, steaming muaj ib tug qis withering kub thiab luv luv lub sij hawm, thiab cov av noo thiab kub ib puag ncig inhibits kev siv ntawm Maillard cov tshuaj tiv thaiv thiab thermal degradation cov tshuaj tiv thaiv. Tag nrho cov tshuaj tsw qab yog qhov qis tshaj ntawm peb cov txheej txheem.
Nws tag nrho cov aroma yog tshiab thiab maj mam, nrog ib tug hint ntawm grassy aroma. Lub concentration, txheej, thiab persistence ntawm aroma yog tsis muaj zog tshaj cov txheej txheem ntawm do frying.
Cias muab, do kib ntsuab muaj ib tug siab aroma thiab muaj zog tsw, thaum steamed ntsuab muaj lub teeb thiab elegant tsw, uas yog ob qho tag nrho txawv aroma.
3.Stir kib ntsuab muaj zog thiab iab saj, thaum steamed ntsuab yog qab zib thiab mos
Qhov sib txawv ntawm saj yog qhov tseem ceeb vim muaj cov khoom tsis zoo ntawm - cov tshuaj tsis hloov pauv hauv tshuaj yej nplooj. Txoj kev tshawb no sib txuas cov hom phiaj kom muaj nuj nqis thiab hluav taws xob tus nplaig saj qhov ntsuas ntiv tes, qhia meej txog qhov sib txawv ntawm cov yam ntxwv saj ntawm ob.
Daim duab 4 Qhov sib txawv ntawm catechins hauv tshuaj yej ntsuab nrog cov txheej txheem sib txawv
Ua ntej, muaj qhov iab.
Tag nrho cov ntsiab lus polyphenol ntawm nruas kib ntsuab yog qhov siab tshaj ntawm peb hom txheej txheem, nrog cov ntsiab lus gallic acid ncav cuag 3.57mg / g.
Polyphenols, tshwj xeeb tshaj yog gallic acid thiab ester catechins, yog qhov tseem ceeb ntawm iab hauv tshuaj yej kua zaub.
Kev txheeb xyuas tus nplaig hauv hluav taws xob kuj tau lees paub tias qhov iab thiab astringency teb qhov tseem ceeb ntawm lub nruas kib ntsuab tshuaj yej yog qhov siab tshaj plaws, muaj zog thiab muaj txiaj ntsig saj, thiab kev nkag siab meej ntawm kev sib koom ua ke.
Daim duab 5 Saj sib txawv ntawm cov tshuaj yej ntsuab nrog txawv cov txheej txheem withering
Tom ntej no yog qhov qab zib.
Qhov kev ua haujlwm qab zib ntawm steamed ntsuab tshuaj yej yog qhov tseem ceeb tshaj plaws, thiab cov lus teb qab zib ntawm tus nplaig hluav taws xob yog qhov siab dua li ob txoj hauv kev.
Yog vim li cas tom qab qhov no yog cov nyhuv dej kub ntawm chav dej, uas tuaj yeem ua rau muaj kev cuam tshuam ntawm hydrolysis ntawm polysaccharides hauv cov tshuaj yej nplooj, ua kom muaj ntau dua soluble monosaccharides thiab oligosaccharides, ncaj qha txhim kho cov qab zib thiab smoothness ntawm cov tshuaj yej kua zaub, ua rau nws saj sweeter thiab softer, thiab tsawg iab.
Daim duab 6 Qhov sib txawv ntawm cov amino acids ntawm cov tshuaj yej ntsuab nrog txawv cov txheej txheem withering
Saib ntawm qhov tshiab thiab caffeine dua.
Dawb amino acids yog cov khoom tseem ceeb rau lub freshness thiab txaus siab ntawm ntsuab tshuaj yej.
Qhov kev sim tau pom tias tag nrho cov amino acid cov ntsiab lus pub dawb ntawm cov txheej txheem sib xyaw ua ke yog qhov siab tshaj plaws, ncav cuag 13983.2 μ g / g, thiab qhov tshiab yog qhov zoo tshaj plaws; tsoos nruas frying ua raws li ntsuab; Tag nrho cov dawb amino acid cov ntsiab lus ntawm steamed ntsuab yog qhov qis tshaj.
Daim duab 7: Qhov sib txawv ntawm Alkaloids ntawm Ntsuab Tshuaj yej nrog Txawv Ntsuab Tshuaj yej Txheej Txheem
Nyob rau hauv cov nqe lus ntawm caffeine tuav, cov txheej txheem roasting muaj ib tug ntau dua tuav tus nqi: cov caffeine cov ntsiab lus ntawm tov roasting ncav cuag 36.88mg / g, nruas roasting yog 26.2mg / g, thiab steaming tsuas yog 18.37mg / g.
Qhov no kuj yog cov khoom siv hauv paus rau ntau tus neeg xav tias cov dej haus ntsuab uas muaj kuab heev thiab tsis tshua muaj kev cuam tshuam rau kev pw tsaug zog.
Feem ntau, tsis muaj qhov zoo tshaj plaws lossis qhov tsis zoo ntawm steaming ntsuab tshuaj yej thiab do frying ntsuab tshuaj yej. Nws tsuas yog cov tswv yim sib txawv uas tsim cov qauv sib txawv: steaming ntsuab tshuaj yej yog ntsuab, moist, qab zib, thiab muaj ib tug mos saj, thaum do frying ntsuab tshuaj yej muaj ib tug muaj zog aroma, muaj zog tsw, thiab muaj zog astringency, tag nrho cov uas yog cov yam ntxwv pawg nyob rau hauv lub ntsuab tshuaj yej tsev neeg. kev nkag siab txog qhov sib txawv ntawm cov khoom siv no tuaj yeem pab peb pom cov yam ntxwv ntawm cov txheej txheem sib txawv kom meej meej, thiab tseem ua rau peb pom qhov zoo thiab cov qauv ntawm cov tshuaj yej ntsuab.
