Lub luag hauj lwm ntawm Grape-Extractable Polyphenols nyob rau hauv lub Generation ntawm Strecker Aldehydes Thiab nyob rau hauv lub Instability ntawm Polyfunctional Mercaptans Thaum lub sij hawm qauv Wine Oxidation Part 2

Thov hu rauoscar.xiao@wecistanche.comyog xav paub ntxiv

Kev sib xyaw ntawm Acetaldehyde

Thaum lub sij hawm oxidative laus, tsawg tshaj li qhov xav tau ntawm acetaldehyde tau sau. Qhov sib txawv ntawm cov qauv yog qhov tseem ceeb tab sis tsis tshua muaj qhov loj, vim tias cov qib sib xyaw ua ke nyob nruab nrab ntawm 1l thiab 15 mg / L thiab tsis cuam tshuam rau cov txiv hmab txiv ntoo.

Nws yuav tsum raug sau tseg tias qib ntawm acetaldehyde accumulated tsawg heev, xav txog qhov loj ntawm O, noj thiab tsis muaj SO. Nws tuaj yeem kwv yees tias yog tias tag nrho 1-HER tsim tau hloov mus rau hauv acetaldehyde, theem tsim tau nyob nruab nrab ntawm 67.5 thiab 56.86 mg Ll, yog li ntawd acetaldehyde accumulated tsuas yog 16-26 feem pua ​​​​ntawm qhov siab tshaj plaws xav tau. Qhov kev tsis sib haum no yuav tsum raug ntaus nqi rau lub peev xwm paub ntawm cawv

thiab rau cov polyphenols teb nrogacetaldehyde10,37 muaj cov tshuaj antioxidants tuaj yeem tua cov 1-HER radical.46 Tam sim no nws tsis tuaj yeem txheeb xyuas qhov tseem ceeb ntawm ob txheej txheem no hauv kev tiv thaiv acetaldehyde tsub zuj zuj. Remarkably, tus nqi ntawm acetaldehyde accumulated yog zoo correlated nrog tag nrho cov nyiaj ntawm phenolic acids (saib Table 2), uas tej zaum yuav qhia tau hais tias qhov qhia tau tias 1-HER radical quenching peev xwm ntawm cov tebchaw * tsis yog ib qho tseem ceeb rau kev txiav txim acetaldehyde tsim.

Thov nias ntawm no kom paub ntxiv

Accumulation ntawm SAS.Kev sib sau ntawm SA yog qhov cuam tshuam loj rau cov qoob loo ntawm cov txiv hmab txiv ntoo uas tau muab rho tawm los ntawm polyphenols, raws li tau pom meej hauv Table 1 thiab hauv daim duab 1. Cov qauv uas muaj polyphenols muab rho tawm los ntawm Tempranillo tau sau cov qib tsawg tshaj plaws ntawm cov tebchaw, qhov nruab nrab ntawm 30 feem pua ​​​​tsawg dua. , dua li cov qauv uas muaj polyphenols muab rho tawm los ntawm Garnacha lossis Moristel. Qhov sib txawv ntawm cov qauv yog qhov tseem ceeb ntawm qhov loj thiab mus txog qhov sib txawv ntawm 2.4 thiab 2.9. Ob aldehydes mus txog qib siab tshaj plaws yog methional thiabphenylacetaldehyde, uas nyob rau hauv ib qho piv txwv los ntawm Garnacha tau pom ntawm 196 thiab 208 ug/L (1.88 thiab 1.73 μMol), feem. Maxima qib mus txog isobutanol, 3-methylbutanal, thiab 2-methylbutanal yog 51, 57, thiab {{10}} ug/L (0.71,0.66, thiab 1.{{16 }} mol), raws. Kev txiav txim siab tias cov amino acids muaj nyob rau hauv tag nrho cov qauv ntawm tib lub concentration (10 mg / L, 60-85} mmol), qhov no txhais tau hais tias methionine thiab phenylalanine muaj ntau reactive dua valine, leucine, thiab isoleucine, nyob rau hauv kev pom zoo nrog yav dhau los 16,38 kev soj ntsuam.'

Raws li cov lus piav qhia hauv Table 2, kev sib sau ntawm SA yog qhov zoo thiab muaj feem cuam tshuam rau cov ntsiab lus ntawm phenolic acids, monomeric flavanols, thiab nonpigmented tannins thiab cuam tshuam tsis zoo rau cov ntsiab lus hauv prodelphinidins, anthocyanins, thiab xim. PLS cov qauv hais txog qib ntawm SA sau nyob rau hauv oxidation rau thawj cov tshuaj muaj pes tsawg leeg ntawm polyphenolic extracts, cais los ntawm cov tsev neeg cov qauv, yog muab nyob rau hauv Table 3. Cov qauv tsim yog heev txaus siab los ntawm cov txheeb cais ntawm view, muaj peev xwm piav qhia ntau tshaj 77. feem pua ​​​​ntawm qhov sib txawv ntawm qhov qub los ntawm kev sib tw hauv txhua qhov xwm txheej. PLS qauv yog qhov yooj yim heev thiab piav qhia SA tsub zuj zuj nrog tsuas yog tsib qhov sib xyaw ua ke sib txawv: anthocyanins, phenolic acids, flavonols, flavanols, thiab mDP. Yog li, cov molecular conformation ntawm cov polyphenols, lawv cov functional pawg, thiab lawv theem ntawm polymerization yog cov yam ntxwv ntawm cov polyphenolic profile uas txhais lub peev xwm ntawm cov qauv mus sau SA. Cov qauv yog qhov tseem ceeb sib npaug rau 5 SAs vim tias lawv muaj kev sib raug zoo. Cov qauv yuav paub meej tias qhov sib txawv ntawm qhov sib txawv coefficients qhia:anthocyanins, flavonols, thiab ntau condensed tannins, tag nrho cov uas muaj zog antioxidants, impede lub tsub zuj zuj ntawm SA, thaum phenolic acids thiabflavanols, uas feem ntau tsis muaj zogantioxidantsthiab tseem tuaj yeem raug faib ua ntau dua rau kev ruaj khov o-quinones, tuaj yeem ua rau cov amino acids los ntawm Strecker degradation, yog li txhawb SA tsim.

Cistanche tuaj yeem txhim kho kev tiv thaiv

Qhov tsis zoo coefficients ntawm anthocyanins nyob rau hauv Tables 2 thiab 3 twb tau pom nyob rau hauv ib daim ntawv qhia dhau los uas lawv tau tentatively ntaus nqi rau lub paub lub peev xwm ntawm anthocyanins rau react nrog aldehydes. Txawm li cas los xij, cov coefficients tsis zoo no yuav tsum muaj feem xyuam nrog cov txheej txheem molecular rearrangements raug kev txom nyem los ntawm cov molecules thaum oxidation. Ntau tus kws sau ntawv tau tshaj tawm tias quinone hauv B nplhaib tsim nyob rau hauv oxidation ntawm di- thiab trihydroxy anthocyanins, uas xav tias yog a-dicarbonyl nyob rau hauv Strecker degradation ntawm cov amino acids, tsuas yog lub xeev hloov pauv sai sai txo 39一43 noj electrons los ntawm qhov cleavage ntawm C nplhaib. Mus koom rau qhov no, anthocyanins tuaj yeem ua cov tshuaj tua kab mob tua kab mob, kom tsis txhob muaj Strecker degradation.

Qhov tsis zoo ntawm kev sib raug zoo ntawm prodelphinidins pom nyob rau hauv Table 2, tej zaum yuav muaj feem xyuam rau lub siab dua electrophilic cwj pwm ntawm lawv quinones, raws li qhia los ntawm Mouls thiab Fulcrand4 thiab Imran li al.45 Prodelphinidins yog loj tsim los ntawm trihydroxylated flavan-3-ols. Xws li tus cwj pwm electrophilic ntau dua yuav ua rau cov quinones tau txais kev sib txawv nrog cov nucleophiles sib txawv, uas yuav txo lawv qhov muaj rau Strecker degradation ntawm amino acids.

Cov cim antioxidant ntau dua ntawm flavonols muaj feem xyuam rau lawv daim ntawv cog lus ob zaug hauv 2-3 carbons thiab rau carbonyl hauv

647 Xws li ob daim ntawv cog lus sib txuas nrog cov neeg nyob hauv C nplhaib. "

quinone tsim nyob rau hauv lub nplhaib B, uas qhia txog qhov sib txawv reactivity.'Tsis tas li ntawd, qee cov flavonols, xws li quercetin, tsim quinones nrog cov qauv geometrical txawv ntawm cov ortho-quinones, uas yuav cuam tshuam qhov induction ntawm Strecker degradation.] Thaum kawg , nyob rau hauv cov ntaub ntawv ntawm mDP, sib nrug los ntawm cov uas twb muaj zog antioxidant cim los yog ntau condensed tannins, nws yuav xav tias steric.

hindrance tuaj yeem txwv qhov ua tau zoo ntawm quinones los ua kom Strecker degradation.

Tag nrho cov no sib piv nrog cov kev muaj peev xwm ntawm flavonols, phenolic acids, thiab nonpigmented tannins los ua quinones, uas yuav piav qhia txog qhov zoo sib xws.

Remarkably, tag nrho cov kev soj ntsuam no yog, nyob rau hauv dav dav, raws li cov tsim los ntawm Carrasco li al.Cov sau phau ntawv no pom tau hais tias lub siab tshaj plaws noj ntawm phenylalanine thiab methionine thaum lub sij hawm caw oxidation coj qhov chaw nyob rau hauv wines uas tsis muaj anthocyanin / tannin ratios thiab nyob rau hauv wines uas muaj qib siab. catechin thiab qib qis ntawm EGCs. Cov cawv no kuj tsis zoo SO, cov neeg siv khoom, uas yuav qhia tau tias SO, tuaj yeem hnov ​​​​mob ntau dua nrog cov electrophilic quinones ntawm peb-

hydroxyl flavanols los yog ntawm anthocyanins dua nrog quinones ntawm dihydroxyl flavanols.

Tsis zoo li cov kev soj ntsuam no, nws tsis ntev los no tau pom tias hauv cov qauv cawv ntawm 80 degree C, catechin thiab EC muaj peev xwm tsim tau phenylacetaldehyde los ntawm Strecker degradation ntawm phenylalanine, tsawg kawg hauv kev sib piv nrog caffeic acid, gallic acid, thiab 3, {{ 3}}dihydroxybenzoic acid. Lwm cov kws tshawb fawb, ua haujlwm ntawm qhov kub siab dua kuj pom cov txiaj ntsig zoo sib xws hais txog qhov muaj peev xwm ntawm catechins los tsim phenylacetaldehyde hauv kev sib raug zoo nrog me me ortho-diphe-nols lossis triphenols, xws li catechol, methyl catechol, lossis pyrogallol. Qhov no yuav tsum raug ntaus nqi rau tus cwj pwm nucleophilic ntawm A nplhaib ntawm catechins, tsis muaj nyob rau hauv cov yooj yim mononuclear phenols. Txawm li cas los xij, peb cov txiaj ntsig tau pom zoo tias catechin thiab EC yog ib qho ntawm cov khoom siv phenolic tshaj plaws uas txhawb nqa Strecker degradation hauv cawv.

Nws yuav tsum raug pom tias me ntsis ntawm cov aldehydes, tshwj tsis yog rau 2-methylbutanal, kuj tau pom nyob rau hauv cov qauv khaws cia hauv tag nrho anoxia. Hauv feem ntau ntawm cov xwm txheej, cov qib yog marginal, feem ntau tsawg dua 5 feem pua ​​​​ntawm cov nyiaj tau los hauv cov txheej txheem oxidation. Nyob rau hauv ob lub cawv accumulating maximal theem ntawm phenylacetaldehyde, txawm li cas los xij, cov qib tsim nyob rau hauv anoxia ntawm cov compound no nyob ze rau 30 ug / L. Qhov siab repeatability tau pom zoo qhia tias nws tsis yog teeb meem nrog cov txheej txheem anoxic. Nws yuav tsum tau xav tias, txawm hais tias qhov kev saib xyuas uas qhov kev sim tau ua tiav, cov qauv ua tiav wine twb muaj qee qhov a-dicarbonyl tuaj yeem tsim cov tshuaj tiv thaiv.

Kev poob ntawm PFMs los ntawm Oxidation. PFMs yog cov khoom tseem ceeb ntawm cov aroma vim tias lawv muaj lub luag haujlwm tseem ceeb hauv kev ua tshiab thiab hom txiv hmab txiv ntoo pom hauv cov cawv txiv hmab.27 Lawv qhov muaj txiaj ntsig yog qhov tseem ceeb rau cov cawv txiv hmab ntev. ntawm PFMs seem tom qab oxidation tsawg heev, raws li tau pom hauv daim duab 2b. Dawb thiab tag nrho qib ntawm 4MMP tshuav nyob nruab nrab ntawm 5 thiab 23 ug / L lossis nruab nrab ntawm 8 thiab 27.5 ug / L, feem; cov 3MH yog nyob nruab nrab ntawm 7 thiab 15ug/L thiab 9 thiab 48.7 ug/L, thaum dawb theem ntawm MHA nyob rau hauv tag nrho cov mob me dua 4.5 ug/L thiab tag nrho cov theem ntawm 4 thiab 13 ug/L. Kev sib piv nrog cov kev tswj hwm anoxic hauv Table 1 qhia tias hauv cov qauv qhia qhov txo qis tshaj plaws (kem taub hau los ntawm min), ntau dua 92 feem pua ​​​​ntawm cov ntawv dawb thiab 100 feem pua ​​​​ntawm tag nrho cov ntaub ntawv ntawm 4MMP thiab 3MH poob los ntawm oxidation. Oxidative poob ntawm MHA tau sib piv me me vim tias qhov sib xyaw no tseem poob los ntawm cov tshuaj hydrolysis, yielding 3MH thiab acetic acid.

Tej zaum vim tias muaj zog oxidation, qhov sib txawv ntawm cov txiv hmab txiv ntoo cultivars tsis meej. Tsuas yog qhov txo qis ntawm cov ntawv dawb ntawm 3MH thiab ntawm tag nrho cov ntaub ntawv ntawm 4MMP thiab MHA tau cuam tshuam nrog cov qoob loo (Table ). Txawm li cas los xij, muaj qhov sib txawv ntawm qhov sib txawv ntawm cov qauv thiab ntawm cov khoom sib txuas, raws li pom tau hauv Table 1.

Qhov sib txawv ntawm cov ntaub ntawv dawb thiab tag nrho yuav tsum raug ntaus nqi rau qhov muaj cov disulfides uas yuav tsim nrog GSH ntxiv rau cov qauv lossis hloov mus rau lwm cov mercaptans uas muaj nyob rau hauv xov xwm, xws li cysteine-nplua nuj haiv neeg proteins coextracted nrog cov polyphenolics, los yog rau ib co mercapto. -polyphenol tsim thaum lub sij hawm npaj cov qauv. Kev tsim cov Disulfide tuaj yeem tiv thaiv qhov tsis tuaj yeem poob ntawm PFMs los ntawm Michael ntxiv rau quinones. Qhov tseeb, kev tshawb fawb tsis ntev los no tau pom tias qhov ruaj khov ntawm cawv piv rau oxidation muaj feem cuam tshuam nrog kev muaj cov sulfur-muaj cov khoom sib txuas, feem ntau yog cov proteins.51, Raws li qib ntawm disulfides ntawm peb, soj ntsuam PFMs muaj kev sib raug zoo ntawm lawv (r {{ 4}}.87, 0.79, thiab 0.69, tseem ceeb ntawm p<0.0001,p=0.0003, and="0.003," for="" the="" pairs="" 4mmp/mha,4mmp/3mh,="" and="" mha/3mp,="" respectively),="" it="" seems="" that="" the="" ability="" to="" form="" disulfides="" is="" mostly="" a="" characteristic="" of="" each="" sample.="" such="" a="" characteristic="" will="" be="" the="" result="" of="" the="" balance="" between="" the="" mercaptans="" present="" in="" the="" unoxidized="" sample="" and="" the="" number="" and="" activity="" of="" quinones="" formed="" during="" oxidation,="" as="" demonstrated="">

Cov qauv ua kom muaj zog ntau dua Nikolantonaki li al.8 quinones thiab muaj tsawg dua mercaptans yuav tsis tshua tsim cov disulfides. Zoo kawg li, theem ntawm disulfides ntawm 4MMP thiab MHA tau cuam tshuam tsis zoo rau qhov nce ntawm tannin kev ua haujlwm (tseem ceeb ntawm p= 0.046 thiab p= 0.004, raws li), uas yuav qhia tau tias kev tsim ntawm cov ntau quinones nquag muaj feem xyuam rau qhov nce ntawm tannin kev ua haujlwm parameter.

Qhov zoo tshaj plaws, qib ntawm tag nrho 4MMP muaj sia nyob tom qab oxidation yog qhov tseem ceeb thiab cuam tshuam tsis zoo rau cov qauv cov ntsiab lus hauv cov xim pigmented tannins (p= 0.0073) thiab kuj muaj kev cuam tshuam zoo nrog kev txo qis hauv pigmented tannins pom thaum lub sij hawm oxidation (p =0.0029), uas qhia tau hais tias 4MMP reacts thaum oxidation feem ntau nrog pigmented tannins. Cov tshuaj tiv thaiv ntawm txiv hmab txiv ntoo tannins nrog volatile thiols tau piav qhia, tab sis tsis muaj cov ntaub ntawv dhau los txog qhov tshwj xeeb reactivity rau pigmented tannins. Xws li reactivity siab dua yuav, txawm li cas los xij, sib haum nrog

lawv paub ntau tus cwj pwm electrophilic. Nyob rau hauv cov ntaub ntawv ntawm MHA, ciaj sia tag nrho cov theem tom qab oxidation tsis zoo cuam tshuam rau qhov nce pom nyob rau hauv tannin kev ua ub no parameter. Remarkably, pigmented tannins muaj feem xyuam rau kev tsim cov nplaum nplaum.

PLS qauv, nyob rau hauv cov ntaub ntawv no, tsis zoo li rau SA (cov ntaub ntawv tsis qhia) PFMs poob nyob rau hauv Anoxic mob. Nyob rau hauv cov ntaub ntawv ntawm cov qauv khaws cia nyob rau hauv anoxia, kuj ceeb heev, muaj ib tug tseem ceeb txo nyob rau hauv cov dawb thiab nyob rau hauv tej rooj plaub kuj muaj tag nrho cov theem ntawm PFMs, raws li tau pom nyob rau hauv daim duab 2a thiab nyob rau hauv daim duab 3. Cov kev txo qis no yuav tsum yog tag nrho ntawm qhov ncaj qha. los yog indirect reactivity ntawm polyphenolic feem rau PFMs thiab tsis mus rau sab nraud oxidation txheej txheem vim anoxia yog nruj heev. Hauv qee qhov piv txwv, xws li cov qauv 5, nws pom tseeb tias feem ntau ntawm qhov txo qis tuaj yeem raug ntaus nqi rau qhov rov qab oxidation ntawm mercaptans los tsim cov disulfides. Txawm li cas los xij, hauv qee qhov lwm tus, xws li cov qauv 3, kev tsim cov tshuaj disulfides yog qhov tsawg kawg nkaus rau 4MMP thiab 3MH, yog li ntawd hauv cov qauv no, PFMs tau poob qis feem ntau los ntawm cov tshuaj tiv thaiv ncaj qha nrog polyphenols. Qhov kev xav no tsis xav tau. Nws yuav tsum raug txiav txim siab tias PAFs tau ua tib zoo muab rho tawm thiab ib zaug rov tsim dua, lawv tau khaws cia rau hauv qhov chaw tsis muaj oxygen ob peb lub lis piam ua ntej qhov kev sim txhawm rau txhawm rau xyuas kom meej tias cov peev xwm redox ntawm cov khoom sib xyaw tsis zoo. Cov txiaj ntsig tau qhia, txawm li cas los xij, tias qhov kev txo qis no tej zaum yuav tsis cuam tshuam nrog qee qhov quinones xav tias tsim thaum lub sijhawm ua qauv thiab lub luag haujlwm rau qhov txo qis ntawm PFMs nyob rau hauv cov xwm txheej anoxic. Ntawm qhov tod tes, unfermented grape extracted polyphenols yuav tsum muaj ntau reactive tshaj wine polyphenols rau mercaptans vim wine polyphenols tau yav tas los nyob rau hauv kev sib cuag nrog me ntsis nqi ntawm H, S thiab mercaptans ua los ntawm poov thaum lub sij hawm fermentation. Kev sim ua haujlwm ntxiv yuav tsum tau ua los ntsuas qhov no.

Nyob rau hauv txhua rooj plaub, muaj ib tug meej cawv ntawm grape cultivar nyob rau theem ntawm dawb thiab tag nrho cov ntaub ntawv tseem tshuav, raws li tau pom nyob rau hauv daim duab 3. Qhov tsawg tshaj plaws reactive polyphenolic extracts yog cov Garnacha, rau cov maxima qib tau soj ntsuam rau peb PFMs. . Qhov zoo kawg li, cov qib ntawm PFMs tseem muaj kev sib raug zoo nrog qhov kev suav ntawm cov qib GC thiab EGC thiab nrog rau cov phenolic acids, thiab lawv tau cuam tshuam tsis zoo nrog cov tannins uas tsis yog pigmented thiab nrog tannin kev ua, raws li tau pom hauv Table 2.

Lwm yam Varietal Aroma Compounds. Hauv kev ua haujlwm tam sim no, tsis muaj fermentative aroma vim tias tag nrho cov haujlwm tau ua nrog cov qauv tsis muaj fermented. Txawm li cas los xij, raws li aroma precursors tau co-extracted nrog polyphenols, muaj ib tug tseem ceeb txoj kev loj hlob ntawm ib co varietal aroma compounds thaum lub sij hawm anoxic los yog oxic cia ntawm cov qauv. Ib yam li hauv cov kev tshawb fawb yav dhau los, qee cov ntawv tshaj tawm tau hais tias oxidation yuav cuam tshuam rau cov tshuaj tsw qab, thiab peb tau tshawb xyuas tshwj xeeb tias oxidation ua rau muaj qhov sib txawv ntawm qhov tsawg kawg peb yam sib txawv ntawm cov tshuaj tsw qab, xws li linalool, geraniol, thiab TDN. Cov txiaj ntsig tau muab rau hauv daim duab 4 thiab qhia tias txawm tias nyob rau hauv qhov muaj zog ntawm oxidation tshwm sim, tsis muaj qhov sib txawv ntawm cov qib ntawm cov tshuaj tsw qab uas tau xaiv hauv cov tshuaj anoxic thiab cov uas pom hauv cov qauv oxidized. Cov txiaj ntsig no sib piv nrog qee qhov kev soj ntsuam yav dhau los los ntawm cov kws sau ntawv sib txawv, suav nrog peb tus kheej, koom nrog cov qib ntawm linalool tuaj yeem cuam tshuam tsis zoo rau O, noj hauv thawj qhov saturation thiab tsis siv los oxidize SO, lossis pom qhov txo qis ntawm linalool ntawm cov. cov qauv khaws cia ntawm 50 degree hauv O.'Nyob rau hauv txoj kev tshawb no tom kawg, kuj tseem muaj qhov nce ntxiv ntawm TDN cuam tshuam rau qhov muaj O. Cov txiaj ntsig tau nthuav tawm ntawm no, txawm li cas los xij, tias nyob rau hauv ib txwm khaws cia, qib ntawm cov tshuaj tsw qab no yog txom nyem los ntawm O.

Kab lus no yog muab rho tawm los ntawm https://doi.org/10.1021/acs.jafc.1c05880 J. Agric. Khoom noj khoom haus Chem. 2021, 69, 15290–15300