Evolution of phenoli nd sensoril hrteristis of rosé wines ged with different lterntive wood hips Inês Filip Sntos Nunes Dissertção pr otenção do Gru de Mestre em Vitiultur e Enologi Orientdor: Professor Doutor Jorge Mnuel Rodrigues Rirdo d Silv Co-orientdor: Professor Doutor António Mnuel Sntos Tomás Jordão Júri: Presidente: Doutor Crlos Mnuel Antunes Lopes, Professor Assoido om Agregção do Instituto Superior de Agronomi d Universidde de Liso. Vogis: Doutor António Mnuel Sntos Tomás Jordäo, Professor Adjunto d Esol Superior Agrári do Instituto Politénio de Viseu; Doutor Aníl José Simões Coutinho, Espeilist do grupo SONAE. Liso, 2017
A g r d e i m e n t o s Após vários nos de ltos e ixos n minh vid démi, sinto que devo os meus suessos todos os que del form prte, todos os professores que me guirm, inspirrm e desfirm, e os olegs que form o poio, jud e mizde que neessitei, espeilmente o João e o Edurdo, que pr lém de migos form um grnde suporte qundo mis preisei nest fse finl. Aos professores Jorge Rirdo d Silv e António Jordão, om quem entrei no que foi um grnde desfio pr mim, e que estiverm sempre prontos dr poio e fzer todos os possíveis pr me judr em todo este proesso, om um grdeimento espeil tmém à professor An Cristin Correi que foi um jud indispensável e edeu tmém o seu poio e disponiilidde. À Cs d Pssrel e AEB Bioquími que forneerm os vinhos e prs de mdeir pr este estudo. Devo um grdeimento enorme à Din Fri, o Dniel Durte e à Juline Oliveir, om quem pssei todo o período experimentl e quem me ompnhou e muito me ensinou no que foi um período de prendizgem muito grnde, por vezes nstivo, e todos os dis estiverm inondiionlmente disponíveis om melhor disposição, que me judou ser onfortável e onfinte num meio que me er ind estrnho. Finlmente todos os meus migos e fmíli, em espeil os meus pis que me trouxerm sempre poio, mizde, ompreensão, e tnto fizerm por mim pr poder qui hegr, ssim omo o meu irmão que sempre me trnsmitiu forç e determinção. Serão todos sempre um grnde inspirção. 1
A s t r t The im of this study ws evluting the effets of herry (Prunus vium) nd ok (Querus petre) hips in the phenoli, voltile nd sensoril profile of Portuguese rosé wine, mde from Tourig ttempting to understnd whether the pplition of ooperge, inluding lterntive woods, is potentilly enhning. For this purpose, severl hemil nlyses were rried out; for musts (t 0, 2, 6, 8,10 nd 20 fermenttion dys), totl phenols, non-flvonoids, hromti hrteristis, nd olour due to opigmenttion were ssyed. For the wines (smpled t 40, 60 nd 80 storge dys), the sme nlysis took ple, s well s HPLC determintion of individul nthoynins, polymide olumn extrtion nd HPLC determintion of pronthoynidins, pronthoynidin seprtion y degree of polymeriztion nd sensory nlysis. Both woods improved olour intensity nd pigment stility, whih ws signifintly more relevnt when using herry wood, nd phenoli ontent ws onsistently higher with this wood, in omprison with the ontrol nd ok wines, the ltter even showing less totl phenols thn the ontrol t one storge point. Both lso hd onsiderly lrger proportion of oloured nthoynins thn the ontrol, more pronouned in the wines fermented nd ged with hips, nd with no disernile dominne of ny wood type, nd ok wood indued n inrese of mlvidin-3-gluoside in storge. Cherry wood lso showed muh higher onentrtion of monomeri proynidins, nmely (+)- tehins, with possile effet of ontt time. From sensory nlysis, wines ged nd/or fermented with wood hips lwys sored highest in overll rting (CHFA t 40 storge dys, CHF t 60 nd OKFA t 80), signifintly improving olour intensity nd overll qulity, s well s woody roms, whih developed more intensely in the wine fermented nd ged with ok hips. There were no definite differenes etween ontt time when using wood, nd results were sometimes irregulr nd with onsiderle ssoited error. Keywords: Cherry, ok, phenoli omposition, rosé wine, sensory nlysis 2
R e s u m o O ojetivo do presente estudo foi vlir os efeitos d plição de prs de erejeir (Prunus vium) e rvlho (Querus petre) um vinho rosé (Tourig Nionl, região do Dão), no perfil fenólio, volátil e sensoril, durnte fermentção (20 dis) e onservção (80 dis), de modo ontriuir pr vlição do uso de mdeirs em rosés, ssim omo o uso de outrs mdeirs em vinifição, omo um lterntiv viável. Pr este efeito, form feits váris nálises químis; pr mostos ( 0, 2, 6, 8, 10 e 20 dis de fermentção) form vlidos os fenóis totis e não flvonóides, rterístis romátis e or devido opigmentção. No so dos vinhos ( 40, 60 e 80 dis de onservção) form feits s mesms nálises menionds pr os mostos, pr lém de poder tnnte, ntoinins individuis por HPLC, extrção por olun de polimid e determinção por HPLC de proinidins, seprção de proinidins por nível de polimerizção e nálise sensoril. Ams s mdeirs fetrm positivmente intensidde e estilidde d or, muito mis signifinte om prs de erejeir, e riquez fenóli foi sempre mior om est mdeir, omprndo om o ontrolo e s mostrs om rvlho. As prs induzirm tmém mior proporção de ntoinins ords, espeilmente nos vinhos tnto fermentdos omo onservdos n su presenç, sem que lgum tipo de mdeir se destque neste prâmetro, e mdeir de rvlho teve um efeito de umento de mlvidin-3-gluósido n onservção. O mior vlor de proinidins monoméris foi tingido om erejeir, prentemente umentndo om o tempo de ontto. Sensorilmente, s mdeirs onferirm s melhores pontuções geris os vinhos, om mis intensidde d or e qulidde, e mis roms rterístios de mdeirs que se desenvolverm mis mrdmente no vinho que fermentou e estgiou om rvlho. Não houverm diferençs signifitivs entre tempos de ontto no so do uso de prs, e os resultdos estiverm muits vezes sujeitos erros pdrão onsideráveis. Plvrs-hve: Análise sensoril, erejeir, rvlho, omposição fenóli, vinho rosé 3
R e s u m o l r g d o O setor vitiviníol é de grnde importâni eonómi pr muitos píses, e o seu resimento ontínuo fz om que sej de grnde interesse dos produtores de lirem onheimentos novos e ntigos de form produzirem vinhos d mior qulidde possível pr os seus merdos-lvo. Os vinhos rosé têm sofrido om estigms negtivos no pssdo por serem vinhos vistos omo desinteressntes, de ix qulidde e pouo sérios, no entnto prour tem umentdo, e onsequentemente produção, e d vez mis se vê vinhos rosés omplexos e inovdores entrrem no merdo. Um ds forms de inovr nestes vinhos, ind pouo explord, ms muito usd em rnos e tintos, é o uso de mdeir n fermentção, onservção em ms s etps. O uso de mdeirs, nomedmente rris, dt desde ntiguidde, e está hoje reservdo vinhos de elevd qulidde, visto que s rris se trduzem num uso pouo efiiente de espço, om ustos onsideráveis. A respost este prolem foi de enontrr lterntivs que permitm ixr os ustos de produção, entrr no merdo mis edo e onseguir vinhos om lgums rterístis nálogs o uso de rris. Assim se provou o uso de frgmentos de mdeir que trzem mis superfíie de ontto om mtriz líquid, elerndo o proesso de trnsferêni de ompostos d mdeir pr o vinho. Mesmo sendo um proesso mis rápido, não será ompletmente nálogo o uso de rris, ms permite que se use em vinhos de gms mis ixs, devido à redução de ustos. O ontto de mostos /vinhos om mdeir trz váris onsequênis, pel trnsferênis de ompostos que oorrem entre os dois meios; o vinho sorve fenóis d mdeir, ltons, entre outros, que fetm onsidervelmente sensção de o (mis mrgor e dstringêni) e torn mis dominntes os roms rterístios ds mdeirs (unilh, espeiris, furânio, et.). Est ontriuição está dependente de vários ftores, omo origem geográfi ds mdeirs, su omposição nturl, ondições de rmzenmento e mnusemento, presenç de oxigénio e orrs e o tipo de trtmentos feitos em tnori, nomedmente operção de tost/queim d mdeir. Reentemente, vários estudos têm prourdo estudr os efeitos de outrs mdeirs em vinifição, pr lém do rvlho e stnheiro, omo sejm s mdeirs de erejeir, ái e moreir, ms ests não são ind permitids, o que por justifir o interesse de estudr o seu potenil omo lterntivos o rvlho, que tem um prour quse exlusiv neste setor, tnto pr rris omo pr os lterntivos, trduzindo-se num grnde impto mientl pr espéie. O presente estudo prourou estudr os poteniis efeitos de prs de erejeir (Prunus vium) e rvlho (Querus petre) no perfil fenólio e sensoril de um vinho rosé, otido por prensgem diret de uvs d st Tourig Nionl, ultivds n região do Dão (Portugl), de form justifir se o uso de produtos de mdeir trz melhormentos num rosé, o mesmo tempo testndo ontriuição de um mdeir lterntiv. Pr este efeito, form feits váris nálises químis; pr mostos form vlidos os teores de fenóis totis e não flvonóides, rterístis romátis e or devido opigmentção. No so dos vinhos, o longo do tempo, form feits s mesms nálises menionds pr os mostos, pr lém de poder tnnte, ntoinins e proinidins individuis por HPLC e ind quntifição ds proinidins 4
de ordo om o seu gru de polimerizção, e, por último, nálise sensoril dos vinhos rosés elordos. O mosto otido iniilmente foi dividido em 3 prtes Controlo, fermentção om prs de erejeir (1.5 g/l) e fermentção om prs de rvlho (1.5g/L) - em us de 1000L, durnte 20 dis de fermentção. Posteriormente, d ensio om mdeir foi dordo em dois; um onservdo em ontto om s prs e o outro onservdo sem mdeir, resultndo num totl de 5 ensios durnte onservção dos vinhos. O uso de prs provoou o umento d intensidde e estilidde d or, priniplmente no so d erejeir que teve um efeito signifitivmente mior n intensidde, ssim omo nos pigmentos polimérios, em ms s fses de vinifição. A tonlidde é tmém um om indidor d evolução quími do vinho, e onsequentemente d su mior ou menor jovilidde, no que to à or, já que o ontrolo teve um mior perd de sorvêni 520 nm (or vermelh) do que os restntes. Tendo em ont o prâmetro de idde quími, este foi superior qundo houve ontto om ms s mdeirs. Este está reliondo om polimerizção de pigmentos, e su estilidde, e é tmém testemunh o ontriuto d mdeir n estilizção d or. Nest determinção, form tmém verifido vlores superiores om utilizção de mdeir de erejeir. Ams s mdeirs promoverm ionizção de ntoinins, mostrndo um mior proporção ds forms ords ou ionizds. Nos vinhos, tl fto poderá dever-se o tempo de ontto, visto que os vinhos que fermentrm e depois estgirm om prs mostrrm vlores esttistimente mis elevdos. Qunto às prontoinidins, onentrção de tequin foi lrmente superior nos vinhos estgidos e/ou fermentdos om prs de erejeir, sem um tendêni identifiável o longo do tempo, enqunto o vinho ontrolo e os vinhos fermentdos e estgidos om prs de rvlho não tiverm diferençs muito signifitivs. Sensorilmente, os vinhos om prs mostrrm melhor evolução de qulidde, e o vinho ontrolo mnteve su vlição de um modo gerl e sempre om lssifição ixo dos restntes, portnto houve um umento de qulidde, ssim omo de intensidde d or que teve signifiâni esttísti mis mrd. Os roms rterístios de mdeirs tornrm-se peretíveis e mdeir de rvlho teve mior evolução desse prâmetro, espeilmente nos vinhos fermentdos e estgidos om prs de rvlho. Este ou por ser um estudo de evolução e omprção mis om o ontrolo, já que s mdeirs mostrrm entre si pens s diferençs já menionds, e otivemos pou signifiâni ns omprções entre tempo de ontto, que tlvez tivessem sido mis identifiáveis om um mior dosgem de prs. O estudo dos métodos proprimente ditos pr o so de rosés é de espeil interesse, ssim omo ontinução de ensios om mdeirs nestes vinhos, e prour de trzer novs mdeirs de potenil interesse o setor viníol. 5
I n d e x Agrdeimentos...1 Astrt...2 Resumo...3 Resumo lrgdo...4 Index...6 Figure index...8 Tle index... 12 1. Introdution... 13 1.1. Winemking tehnologies of rosé wines... 13 1.1.1. Diret pressing... 14 1.1.2. Pre-fermenttive mertion... 15 1.1.3. Drwing-off (Signée)... 17 1.1.4. Croni mertion... 17 1.1.5. Fermenttion nd storge in wood... 19 1.2. Rosé wine omposition nd mturtion... 19 2. Wood in enology... 21 2.1. Ok omposition nd its impt on wine... 21 2.2. Ftors tht ffet wood ontriution nd intertion with wines... 23 2.3. Alterntive wood produts... 27 2.4. Potentil lterntive wood speies for enology... 28 2.4.1. Cherry (Prunus vium)... 28 2.4.2. Ai (Roini pseudoi)... 30 2.4.3. Chestnut (Cstne stiv)... 30 3. Ojetive of the study... 32 4. Mteril nd methods... 33 4.1. Wine nd wood mterils... 33 4.1.1. Experimentl onditions... 33 4.2. Chemil prmeters... 35 4.2.1. Totl phenols; non-flvonoid nd flvonoid phenols... 35 4.2.2. Colour intensity nd hue... 36 4.2.3. Anthoynins nd polymeri pigments... 36 4.2.4. Chemil ge... 38 4.2.5. Colour due to opigmenttion... 38 4.2.6. Pronthoynidins... 39 4.3. Sensory nlysis... 41 4.4. Sttistil nlysis... 41 5. Results nd disussion... 42 6
5.1 Must nlysis during loholi fermenttion... 42 5.1.1 Totl phenols, non-flvonoid nd flvonoid phenols... 42 5.1.2 Totl nthoynins nd pigments... 43 5.1.3 Colour prmeters intensity nd hue... 45 5.1.4 Chemil ge... 46 5.1.5 Colour due to opigmenttion... 47 5.2. Wines nlysis during storge... 48 5.2.1 Totl phenols; non-flvonoid nd flvonoid phenols... 48 5.2.2 Totl nthoynins nd pigments... 49 5.2.3 Colour intensity nd hue... 54 5.2.4 Chemil ge... 56 5.2.5. Colour due to opigmenttion... 57... 57 5.2.6. Pronthoynidins... 58 6.8. Sensory nlysis... 63 6. Conlusions... 66 7. Referenes... 67 7
F i g u r e i n d e x Figure 1 - Representtion of typil rosé olour rnge, s funtion of mertion time. (Soure: Wine Folly t http://winefolly.om/review/wht-is-rose-wine/)... 15 Figure 2 - Comprison of two rosés mde from the sme grpes, one produed y diret pressing (Left) nd the other otined from Signée (Right). Soure: Vinous t http://vinous.om/rtiles/the-rose-roundup-of-2015- pr-2015... 17 Figure 3 Geogrphi distriution of (A) Querus sessilis, (B) Q.rour nd (C) Q. l (in Jkson, 2008; Artwork y Hermn Csteleyn.... 21 Figure 4 - Ok wood lterntives; Smll hips, lrge hips nd dust. Fonte:www.theyhtruwineguide.om/log/2015/2/24/to-ok-or-not-to-ok... 27 Figure 5 Digrm representing the experimentl onditions for this study. Legend: Control: ontrol must nd wine, CH: must fermented with herry hips, OK: must fermented with ok hips, CHFA: wine ged with herry hips, CHF: wine ged without herry hips, OKFA: wine ged with ok hips, OKF: wine ged without ok hips... 34 Figure 6 - Evolution of totl phenols nd non-flvonoids during loholi fermenttion of rosé must in ontt with different wood hips. Legend: CONTROL: Control must; CH: must fermented in ontt with herry hips; OK: must fermented in ontt with ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 42 Figure 7 - Evolution of totl nd oloured nthoynins during loholi fermenttion of rosé must in ontt with different wood hips. Legend: CONTROL: Control must; CH: must fermented in ontt with herry hips; OK: must fermented in ontt with ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 43 Figure 8 - Evolution of totl nd polymeri pigments during loholi fermenttion of rosé must in ontt with different wood hips. Legend: CONTROL: Control must; CH: must fermented in ontt with herry hips; OK: must fermented in ontt with ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 44 Figure 9 - Evolution of polymeriztion index during loholi fermenttion of rosé must in ontt with different wood hips. Legend: CONTROL: Control must; CH: must fermented in ontt with herry hips; OK: must fermented in ontt with ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 45 Figure 10 - Evolution of olour intensity nd hue during loholi fermenttion of rosé must in ontt with different wood hips. Legend: CONTROL: Control must; CH: must fermented in ontt with herry hips; OK: must fermented in ontt with ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 46 8
Figure 11 Evolution of hemil ge during loholi fermenttion of rosé must in ontt with different wood hips. Legend: CONTROL: Control must; CH: must fermented in ontt with herry hips; OK: must fermented in ontt with ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 46 Figure 12 - Evolution of olour due to opigmenttion during loholi fermenttion of rosé must in ontt with different wood hips. Legend: CONTROL: Control must; CH: must fermented in ontt with herry hips; OK: must fermented in ontt with ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 47 Figure 13 - Evolution of totl nd non-flvonoid phenols during storge of rosé wine in urrent nd/or previous ontt with different wood hips. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 48 Figure 14 Evolution of totl nd ionized nthoynins during storge of rosé wine in urrent nd/or previous ontt with different wood hips.. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 49 Figure 15 - Evolution of totl nd ionized nthoynins during storge of rosé wine in urrent nd/or previous ontt with different wood hips.. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 50 Figure 16 Evolution of monomeri nthoynins during storge of rosé wine in urrent nd/or previous ontt with different wood hips, determined y HPLC. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 52 Figure 17 Distriution of quntified individul nthoynins, in mg/l, s determined y HPLC, during storge of rosé wine. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips; Delf 3 gl: delfinidin-3-o-monogluoside, Pet 3 gl: petunidin-3-omonogluoside, Peo 3 gl: peonidin-3-o-monogluoside, Ml 3 gl: mlvidin-3-o-monogluoside, Ml 3 gl-: mlvidin-3-o-monogluoside-ette, Ml 3 gl-o: mlvidin-3-o-monogluoside-oumrte. Wines re represented s (Assy-Storge period in dys)... 53 Figure 18 Evolution of totl nd polymeri pigments during storge of rosé wine in urrent nd/or previous ontt with different wood hips. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 53 9
Figure 19 Evolution of polymeriztion index during storge of rosé wine in urrent nd/or previous ontt with different wood hips. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 54 Figure 20 Evolution of olour intensity nd hue during storge of rosé wine in urrent nd/or previous ontt with different wood hips. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 55 Figure 21 Evolution of hemil ge feture during storge of rosé wine in urrent nd/or previous ontt with different wood hips. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 56 Figure 22 Evolution of olour due to opigmenttion feture during storge of rosé wine in urrent nd/or previous ontt with different wood hips. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 57 Figure 23 Evolution of tehins nd epitehins during storge of rosé wine in urrent nd/or previous ontt with different wood hips. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 58 Figure 24 Evolution of individul pronthoynidins during storge of rosé wine in urrent nd/or previous ontt with different wood hips. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 59 Figure 25 Distriution of quntified individul proynidins, in mg/l, s determined y HPLC, fter 40, 60 nd 80 storge dys of rosé wine. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Wines re represented s (Assy-Storge period in dys)... 60 Figure 26 Evolution of monomeri, oligomeri nd polymeri pronthoynidin frtions during storge of rosé wine in urrent nd/or previous ontt with different wood hips. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. Men vlues with the sme letter indite no sttistilly signifint differenes (Tukey s test t p<0.05)... 61 10
Figure 27 - Distriution of pronthoynidins y degree of polymeriztion during storge of rosé wine. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips, F1: monomeri pronthoynidins, F2: oligomeri pronthoynidins, F3: polymeri pronthoynidins. Wines re represented s (Assy-Storge period in dys).... 61 Figure 28 - Sensory nlysis results for the studied wines, t 40 storge dys. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. An sterisk (*) represents signifint differenes etween the wines (Tukey s test, p<0.05)... 63 Figure 29 Sensory nlysis results for the studied wines, t 60 storge dys. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. An sterisk (*) represents signifint differenes etween the wines (Tukey s test, p<0.05)... 64 Figure 30 - Sensory nlysis results for the studied wines, t 80 storge dys. Legend: CONTROL: Control wine; CHFA: wine fermented nd ged with herry hips, CHF: wine fermented with nd ged without herry hips, OKFA: wine fermented nd ged with ok hips, OKF: wine fermented with nd ged without ok hips. An sterisk (*) represents signifint differenes etween the wines (Tukey s test, p<0.05)... 65 11
T l e i n d e x Tle 1 - Comprison of phenoli extrtion in two rosé wine mde from the sme grpes, vrying SO2 onentrtion during mertion (Sudrud et l.., 1968) 16 Tle 2 - Comprison etween the omposition of rosé nd red wines (Blouin nd Peynud, 2001)...19 Tle 3 - Tle 3 Phenoli omposition, nthoynins nd olour of severl Frenh rosé wines (Riéreu- Gyon et l., 1976). Colour intensity nd hue re expressed in sorne units...20 Tle 4 - Influene of sesoning method on ok omposition (dpted from Chtonnet, 1995)...23 Tle 5 - Summry nlysis of the wine used in the study...33 12
1. I n t r o d u t i o n 1.1. Winemking tehnologies of rosé wines The winemking setor is of the utmost ulturl nd eonomi importne to mny ountries throughout the world, nd ever-evolving, thus foring winemkers to onstntly strive for innovtion nd wys to stnd out in growing glol mrket. Rosé wines re n inresingly populr style of wine, lthough lking speifi guidelines or lws to offiilly define it. A rosé is often onsidered to e intermedite etween red nd white wine, sine it omines the freshness, fruitiness, idity nd young roms nd typilly lower lohol ontent, with ertin mount of phenoli ompounds lower thn reds. (Fuvet nd Guittrd, 1998). As mentioned y severl uthors (André nd Auert, 1970; Gri Jres et l., 1993; Riéreu-Gyon et l., 2006), nd ording to EC douments, rosé wines lk preise definition. The diffiulty sits on the severl vrieties nd winemking tehniques tht n e used to produe them, s well s wide rnge of nlytil olour prmeters whih ould ontriute to hrterize rosé wine (Riéreu- Gyon et l., 2006). Due to suh duiety, the only prmeter urrently leding to identifying wine s rosé is its visile olour, generlly sitting etween tht of white nd red wine, nd rnging from more ornge tints suh s onion skin to deeper herry reds, while ppering generlly lighter thn red wine. The olour rnge of rosé wines, s well s their generl hrteristis nd qulity, depend on mny ftors suh s vrieties used nd winemking tehniques employed. Aording to Fuvet nd Guittrd (1998), three min issues stnd out while produing rosé; Choosing the omintion of grpe vrieties, s well s the pproprite hrvest time. Extrting the most romti qulities possile, while lso keeping the olour to minimum, in limited mount of time. Estlishing the est storge onditions so the wine n keep its young hrteristis. Regrding grpe vrieties, rosés n e mde with ny red grpes, s well s mixture of red nd white vrieties in some ses, ut typilly hoosing red grpes tht re likely to onfer right olours, fruity roms nd moderte red pigment (Amerine nd Singleton, 1977). The pproprite mturtion hieved efore hrvest depends on the finl produt, nd whether the gol is risp, light rosé or fuller ody; Riéreu-Gyon et l. (2006) onstrue tht grpes intended for the former se should not exeed ripeness or 12% of ethnol y volume, while lso mintining reltively high idity, while grpes intended for the ltter should hve slightly higher loholi ontent nd lower idity. A night-time hrvest is sometimes dvised to help preserve the fruity roms in grpes. Typilly, fermenttion of rosé wine should e rried out etween 15 nd 20 C, llowing the temperture to rise to 20-22 C during the finl stges (Fuvet nd Guittrd, 1998). Temperture is prtiulrly importnt to the development of grpe sed roms nd the voltile y-produts known s 13
fermenttion ouquet, formed y most strins of the Shromyes yest when temperture is kept t 20 C or elow, whih is desirle in young fruity wines suh s typil rosé, however these esters re so voltile they my hydrolyse within months of storge if tempertures re not kept low enough (Boulton et l., 1995). If fermenttion tempertures re kept too high, the flvour profile will hnge s these esters give ple to higher lohols, ethnol my deplete, omintion of SO2 my e promoted, rendering it useless, nd there is more onsiderle risk of stopping fermenttion ltogether. Allowing mlolti fermenttion (MLF) to follow is onsidered optionl in rosé winemking, s it is importnt to preserve freshness nd hieve the est lohol-idity lne. MLF my e llowed or indued if the min ojetive is to produe older rosé, espeilly when there ws prolonged mertion, s lower idity resulting from MLF will help soften the tnnins (Riéreu-Gyon et l., 2006). André et l. (1971) verified tht the deidifition whih ours from MLF lso uses nthoynins to derese in olour, due to eing in lower idity medium, resulting in generl derese of olour intensity in rosés. The min winemking methods for rosé wines re diret pressing, prolonged skin ontt nd Signée (or drwing off). Croni mertion is not s ommon ut my e used, however it often results in wines tht re too deep in olour, ultimtely hving to e lended with lighter olour wines (Fuvet nd Guittrd, 1998). The use of wooden ooperge is not widely studied nd doumented. 1.1.1. Diret pressing Diret pressing is winemking tehnique mostly ssoited with white wines, onsisting in diret pressing of the grpes s they enter the winery, nd using free run juie nd the resulting press juie for vinifition. This llows for short mertion time whih ours only during the pressing opertion, whih in turn llows for some extrtion of phenoli ompounds; higher pressure results in higher phenoli ontent (Riéreu-Gyon et l., 2006). In diret pressing, the must is seprted from every solid omponent, mening ll further stges our in stritly liquid stte, with no more omponents eing extrted from the grpes. Two seprte musts n result from this proess; free run juie nd press juie. Free run juie is usully riher in sugr, ids nd romti ompounds, while lking in totl polyphenols in omprison with the lter extrted musts, whih hve hd short period of ontt with skins nd thus some polyphenols hve een extrted (Dis Crdoso, 2007). Depending on the desired hrteristis of the finl produt, the different musts n e omined in different mnners. Press juie should e seleted nd lended with free run juie in determined mounts if this ontrolled lending is desired, nd the juie from the lst pressing yle my even e eliminted, due to hving more vegetl tste nd supplying more tnnins thn nthoynins (Riéreu-Gyon et l., 2006). After extrtion, it is importnt to protet the must from oxidtion through sulfiting, possily ssoiting this opertion with the use of dry ie or inert gs injetion in the press or vt (Dis Crdoso, 2007), lso lled inert gs lnketing. This minimises the oxygen pikup from the ir to the juie during severl stges, from hrvesting to pressing, nd typilly using ron dioxide or nitrogen (Boulton et l., 1995). 14
Clrifition of the must follows, iming to seprte the gross lees from the must, preeding fermenttion. This opertion is optionl, nd it tends to refine the rom nd righten olour s well s lower the suseptiility to oxidtion (lthough due to nthoynin fixtion)(riéreu-gyon et l., 2006). Fuvet nd Guittrd (1998) referene n idel NTU (Nephelometri Turidity Unit) level of 100-200 NTU for rosé must. Exessive lrifition my ring diffiulties lter on, in fermenttion, due to the lk or heterogenous distriution of polyshrides in the vt; lrifition removes polyshrides nd lees, reduing the support effet neessry for optiml fermentility (Riéreu-Gyon et l., 2006). When working with non-romti vrieties (most in Portugl s se), the seondry/fermenttive roms eome predominnt in wine mde y diret pressing, mking it thin wine, lking persistene nd vrietl hrter. These roms re highly unstle nd modify notiely fter out one yer (Dis Crdoso, 2007). 1.1.2. Pre-fermenttive mertion Rosé wines n lso e produed while llowing for more prolonged ontt with grpe skins efore fermenttion pre-fermenttive mertion lsting from 2 to 20 hours of ontt, depending on grpe vrieties nd ripeness, s well s hrvest temperture (Fuvet nd Guittrd, 1998). During mertion, phenoli ompounds, s well s mino ids, ftty ids nd higher lohols re extrted (Soufleros nd Bertrnd, 1988), whih interfere in the rom, struture nd qulity of wines, in n mount proportionl to the ontt time, reting older, rounder nd more deeply oloured wines in omprison with diret pressing (figure 1). Exessive skin ontt n result in wines tht re too itter or stringent, nd possily with too muh olour, whih hllenges its identity s rosé wine. Figure 1 - Representtion of typil rosé olour rnge, s funtion of mertion time. (Soure: Wine Folly t http://winefolly.om/review/wht-is-rose-wine/) A short mertion extrts less nthoynins (Keleek et l., 2007; Surino et l., 2015), justifying rosé s pler, pinkish hue, yet these still pper s importnt ntioxidnts nd, onsequently, preservtives of fruity roms, whih re lso very hrteristi of typil rosé wines. Beuse fewer 15
tnnins re lso extrted with shorter mertion times, olour stility is ompromised, sine muh of the olour is ultimtely due to free nthoynins nd their self-ssoition nd opigmenttion proesses. Surino et l. (2015) found tht mertion time ws positively orrelted with olour stility, ut not fvourle towrds fruity nd florl roms, s shown y hromtogrphy nd sensory nlysis, when onsidering mertion times of 3, 6 nd 8 hours. The sme uthors lso otined results regrding the effet of skin mertion on olour, with less intensity nd violet hues in the shortest mertion time (3h). Besides ontt time, other ftors deeply ffet mertion effetiveness, suh s SO2 levels in the must. Aording to Sudrud et l. (1968), the ddition of SO2 hs shown to promote nthoynin dissolution nd enhnement of olour, lowering the tnnin/nthoynin rtio, nd generlly fvouring phenoli extrtion. The results of this study, onduted in rosé wines, ompring extrtion with nd without the presene of SO2 nd onsidering mertion period of 12 hours, re shown in tle 1. Tle 1 - Comprison of phenoli extrtion in two rosé wine mde from the sme grpes, vrying SO2 onentrtion during mertion (Sudrud et l.., 1968) SO2 onentrtion Totl phenoli index (.u.) Totl Anthoynins (mg/l) Tnnins (mg/l) Colour intensity (.u) Tnnin/nth. None 11 26 320 0.52 12.3 10 g/hl 16 100 760 1.53 7.6 rtio These results support tht sulfiting musts is good prtie when more extrtion is needed during mertion, ut lso when iming to protet the musts from spoilge nd oxidtion. Regrding temperture, Jkson (2008) mentions mertion under 20 C retrds miroil tion, nd Murt (2005) found the top of this rnge to e preferle, due to more effetive extrtion of n importnt frgrne preursor present in the skins (S-3-hexn-1-ol-L-ysteine). This ompound s onversion into 3-merptohexn-1-ol is responsile for fruity roms. Crhereu (2009) reommends the temperture is kept within this low rnge, to enle settling phse nd slow down olour diffusion. The presene of petolyti enzymes will lso ffet the resulting musts. Slins et l. (2003) hve found tht the ddition of these enzymes during mertion to improve flvour development nd olour stility, however it required out 12h of mertion to produe signifint differenes in the studied wine, nd this time is even longer when lower tempertures re used in these preprtions. Suh issues hve used this to not e widespred prtie in rosé winemking, ut severl uthors hve studied the employment of reltively new tehnique; the use of pulsed eletri fields, or PEF, whih onsists in pplying externl eletri fields tht inrese the memrnes permeility, enhning the diffusion proesses nd promoting extrtion of nthoynins nd vrietl roms, tested in oth red nd rosé winemking (Puértols et l., 2010), mking this promising lterntive for improving pre-fermenttive mertion espeilly t lower tempertures when the use of enzymes is hindered. 16
1.1.3. Drwing-off (Signée) Prolonged skin ontt is generlly imed t mking older rosé wine, while drwing off is imed t produing more onentrted red wine, y drining some of the liquid from the vt, thus produing rosé from the drwn off juie, s y-produt, nd repling the removed liquid with more rushed grpes, inresing the phenoli ontent nd olour of the remining red wine (Riéreu-Gyon et l., 2006). In this se, the grpes re rushed, stemmed nd pled in losed vt in low temperture, for period of 10 to 36 hours (Riéreu-Gyon et l., 2006), following whih the liquid is seprted y drwing off from the vt. Anlogous to the previous method, the mertion time should e determined y the desired hrteristis for the finl produt, tking into ount its previously mentioned effets. Fermenttion will then proeed similrly to musts otined from diret pressing, without the presene of solid prts, produing rosé tht is typilly older nd with stronger red pigment thn diret pressed wine, due to the mertion tht tkes ple efore the drwing off (figure 2). Figure 2 - Comprison of two rosés mde from the sme grpes, one produed y diret pressing (Left) nd the other otined from Signée (Right). Soure: Vinous t http://vinous.om/rtiles/the-rose-roundup-of-2015-pr- 2015 1.1.4. Croni mertion Croni mertion is n lterntive skin ontt method, in whih the intt erries re provided CO2 sturted tmosphere to ondut prtil fermenttion y the grpe s ntive glyolyti enzymes, in neroi onditions tking dvntge of nturlly ourring phenomen (Boulton et l., 1995). This ould e hieved with the ddition of nitrogen; however, ron dioxide is typilly preferred due to eing more redily sored y ytoplsm (Yurglevith nd Jnes,1988) nd hving shown to indue synthesis of grpe petinses whih re mertion enzymes, promoting extrtion (Jkson, 2008). 17
Aording to Flnzy (1998) there re three independent phenomen in roni mertion: Intt erries nturl neroi metolism; Exhnge y diffusion; Fermenttions (nturlly relesed must). The erry s neroi metolism is nturlly triggered when quikly trnsferred to n oxygen deprived tmosphere, through pre-existing enzymti systems, minly lohol dehydrogense enzymes, whih plys key role in providing energy in neroi onditions (Suvge et l.,1991). As grpes re put in CO2 medium, they swith from respirtory metolism to fermenttive one. Intrellulr grpe fermenttion is similr to tht performed y yests, produing minly ethnol, lthough in smller mounts thn yest fermenttion (Flnzy et l., 1995). Aording to Jkson (2008), grpe synthesis of ethnol rrely exeeds 2%. During this fermenttive stte, grpes sor CO2 depending on vriety nd temperture, ut fter point of sturtion they lso relese CO2, due prtly to intrellulr fermenttion (Flnzy et l., 1995). Grpes stop produing CO2 when ells egin to die due to ethnol toxiity or insuffiient energy supply, t whih point ll ontrol of memrne movements stops, nd the grpe ells egin the relese of severl ompounds, most importntly phenols. Croni mertion lso progressively wekens the erries due to petin rekdown (Jkson, 2008). Up to 15-60% of mli id is lso metolised into other ids nd ethnol during grpe ell fermenttion, depending on grpe vriety nd temperture, using derese in idity (Flnzy et l., 1995). Croni mertion should e rried out in shllow vt, whih llows for esier loding, oxygen removl nd CO2 relese, nd vt loding should e rried out with re to preserve erry integrity. Mnul hrvest is reommended for the sme purpose, nd hrvesting in sunny wrm onditions llows for quik-strting grpe ell fermenttion (Jkson, 2008). Alterntively, erries my lso e heted. Temperture is one of the most relevnt ftors; idelly, the proess would strt t out 30-35 C (Flnzy et l., 1995), ut this my e hrder to ontrol thn in onventionl vinifition, seeing s the ontent of the vt is mostly in solid form. Typilly, the entire proess lsts 6-8 dys, up to 2 weeks, nd durtion depends on the temperture s well. For rosé, André et l. (1980) reommend, for exmple, 36 hours t 35 C, or 48 hours t 25 C, for the initil phse. The inomil of durtion-temperture n e used to mnge the intensity of the romti effets of roni mertion. After ompleting roni mertion, free run juie is drwn off the vt, nd the grpes re then pressed, nd oth juies my e fermented together or seprtely, ut should e ooled t temperture of 18-22 C. Fermenttion is very quik nd ould e omplete within 48 hours (Jkson, 2008). This method produes fruity, smooth wines nd, depending on vriety, my msk or enhne their vrietl hrter (Jkson, 2008). In prodution of rosés, nthoynin nd tnnin extrtion re ontrolled y keeping the grpes from sumerging. 18
1.1.5. Fermenttion nd storge in wood Few studies hve een rried out on the impt of wooden ooperge in rosé wines, e it fermenttion nd storge in rrels or in ontt with wooden hips or stves. However, this is known prtie, whih my e inresingly employed, sine the rosé mrket is growing nd entering new nihes, sprking interest of new onsumer types nd distning itself from feminine or low sttus desriptions, or onsidered unworthy of ritil exmintion y ritis (Fitzmurie, 2007). Entering lrger nd more serious mrkets, wooden produts my e vessel for reting rosés tht stnd out, while reting more omplexity, however this is lking sujet in pulished literture. Brgnç (2013) rried out n ssy using severl types of ooperge in rosés, providing wooden ontt during fermenttion nd geing, either in ok rrels of three different speies (Q. petre, Q.pyreni nd Q.l) or using wooden stves from oth Q. l nd Q. petre, seprtely. The uthor onluded tht fter 3 months of storge, wines fermented nd ged in ok rrels hd more positive ppreition, nd were onsidered more omplex y the tsting pnel, without itterness or stringeny, whih would e mostly negtive in rosé, ut these showed less improvement in olour intensity thn the ontrol wine nd wines fermented nd ged with stves. More reently, Sntos (2017) mde similr omprison in rosé wines, studying the effet of 20-dy ontt during storge, oth prior to fining nd fter fining, with hips of two types of oks, s well s herry nd i wood. Cherry wood ged wines were given signifintly etter overll rting in tsting, followed y i wood nd the ontrol wine. In this study s onditions, no signifint differene ws found in olour intensity, when ompred to the ontrol, ut wood showed n effet in totl phenol ontent, s would e expeted due to the extrtility of phenoli omponents from wood. 1.2. Rosé wine omposition nd mturtion Rosé wine omposition is very vrile, depending on wine types, from the light nd fruity pinkish wines, with low phenoli ontents, to deeper red olours high in nthoynins nd tnnins. Rosé wines hve muh lower phenoli (Blouin nd Peynud, 2001; Li et l., 2009) nd nthoynin ontent thn red wines (Blouin nd Peynud, 2001) (tle 2), nd n hve severl differenes mong themselves depending on vinifition methods (tle 3). Tle 2 Comprtive phenoli omposition, etween rosé nd red wines (Blouin nd Peynud, 2001) Totl phenoli index (.u.) Totl Anthoynins (mg/l) Rosé 8-18 20-50 Young red wine 10-30 90-250 Red wine with ging potentil >40 >350 19
Tle 3 Phenoli omposition, nthoynins nd olour of severl Frenh rosé wines (Riéreu-Gyon et l., 1976). Colour intensity nd hue re expressed in sorne units. TPI (.u.) Totl Anthoynins (mg/l) Tnnins (mg/l) Colour intensity (.u.) Hue Tnnin/Anthoynin Rtio Anjou 0.10-2.00 0.50-1.80 Bérn 7-14 14-74 150-430 0.76-1.18 4.3-10.4 Bourdeux Rosé 7-11 35-41 440-850 0.69-1.67 10.0-21.1 Bordeux liret 10-14 115-160 720-800 1.05-1.50 5.3-6.3 Côtes de Provene (Diret pressing) Côtes de Provene (Free run) 7-11 14-55 80-320 0.38-1.19 0.80-1.98 5.6-15.8 7-15 11-62 63-270 0.51-1.76 0.58-1.62 2.1-7.8 Midi (Diret pressing) 10-14 13-35 180-320 0.63-1.19 0.80-1.17 5.6-15.8 The fruity young roms ssoited with rosé wines re mostly fermenttive, from ompounds relesed during fermenttion (Mris, 1983; Bumes et l., 1986). Reserh hs shown the most relevnt preursors of rosés fruitiness to inlude ethyl esters, higher lohol ettes, furneol nd the thiols 3-MH (3-merpto-1-hexnol) nd 3-MHA (3-merptohexyl ette), s well s the norisoprenoid β-dmsenone (Murt, 2005; Ferreir et l., 2009; Msson nd Shneider, 2009; Álvrez-Pérez et l., 2012; Drii et l., 2014). The 3-MH thiol hs een highlighted, nd ssoited with grpefruit nd pssionfruit roms. Consequently, the romti profiles of rosés depend on grpe vrieties, winemking opertions, ompound diffusion onditions (mertion, for exmple) nd yest strins. Both rom nd olour re very voltile during storge, nd rosé wine must e le to keep its qulities over time. Colour nd stility during geing re hevily influened y nthoynins extrted from skins nd the proesses of ssoition nd opigmenttion tht our (Boulton, 2001). As suh, rosés sujeted to prior mertion my e onsidered more vile for geing, sine pre-fermenttive mertion is known to enhne the presene of voltile nd non-voltile ompounds (Arnold nd Nole, 1979; Mris nd Rpp, 1988; Surino et l., 2015), whih re minly present in skins nd ontriute to olour nd roms. These re importnt protetive ompounds whih re usully lower in rosé wines thn reds, justifying more sensitive olour ompounds, s oserved y Stvek et l. (2012). This uthor lso found results supporting the role of storge temperture; room temperture used redution of nthoynin onentrtion of out 50% when ompred to storge t 3 C. Colour intensity tends to derese, s nthoynins grdully polymerize (Del Álmo nd Dominguez, 2006) resulting in derese of red olour (Romn et l., 2013). These hnges persist fter ottling, ording to experimentl results y Hernández et l. (2011), in rosés from different denomintions, finding derese in the red-green oordinte (prmeter * in the CIELAB method). Menwhile, prmeter * (yellow) inresed, espeilly in the first 6 months in ottle. In n ttempt to lssify typil olourtions, the uthors oserved similr evolution in ll smples, from rsperry olour to strwerry in 3 to 4 months, followed y redurrnt 6-8 months lter. Two of the smples rehed slmon olour fter 16 months. 20
2. W o o d i n e n o l o g y 2.1. Ok omposition nd its impt on wine Ok wood is undoutedly the most trditionlly used wood type in winemking. Its genus hs round 300 known speies, nd differenes re found not only etween speies ut lso due to the geogrphil origin of the wood. White ok hertwood is the most used for rrel prodution, minly Q. rour L. nd Q. sessilis L. in Europe, nd Q. l L. in Ameri. These speies min geogrphil distriution is represented elow, in figure 3. Figure 3 Geogrphi distriution of (A) Querus sessilis, (B) Q.rour nd (C) Q. l (in Jkson, 2008; Artwork y Hermn Csteleyn. The min omponents in ok wood re, s in other types of woods, ell wll onstituents; ellulose, hemiellulose nd lignin. Additionlly, it ontins other sustnes with lower moleulr weight, extrtile in hydroloholi solutions, suh s enzoi nd innmi ompounds, hydrolysle tnnins, glli nd ellgi ids nd furni ompounds (Zhng et l., 2015), s well s ltones, the min voltile omponent in ok wood whih slowly dissolves into wine (Jkson, 2008).These ompounds strongly influene the rom of wines, providing typil flvours of vnill, spies, smoke nd even erries, ut lso influene wine olour, ontriuting to its stilistion due to the intertions etween extrted ellgitnnins nd nthoynins nd flvnols (Brrer-Gri et l., 2007). More thn 200 voltile ompounds hve een identified in ok, nd even smll extrtion n signifintly ffet the ouquet, unlike non-voltile ompounds, whih need to e sored in muh lrger portions to influene tste, pperne or mouth feel. Aording to Jkson (2008) wine sors out 30% of essile tnnins, whih is enough to hnge the sensory hrteristis. The most relevnt extrtle sustnes in ok wood re ellgitnnins, glli nd ellgi id, romti ompounds suh s ltones, nd ldehydes. In turn, ok wood dsors mostly wter nd lohol, ut 21
most importntly some wine romtis (fruit esters) (Rmirez-Rmirez et l., 2004) reduing the fruity romti hrteristi of young wines. Regrding non-voltile phenols, ok tnnins hve n importnt ntioxidnt role, onsequently promoting olour stility (Vivs nd Glories, 1996). Ok wood is hrterised y the presene of hydrolysle tnnins, in mjority ellgitnnins (Chen,1970; Seikel et l., 1971) nd gllotnnins (Jkson, 2008), most of whih orrespond to veslgin nd stlgin (Jordão et l., 2016). Ellgitnnins hve een found to signifintly inrese over wine geing time (Nvrro et l., 2016), however, this ws not onsistently oserved in onseutive smples, possily due to hydrolystion (Peng et l., 1991; Mihel et l., 2011) nd trnsformtion (Jourdes et l., 2009) of these ompounds, so the finl onsidered results orrespond to the equilirium etween the relese from ok wood nd its degrdtion/trnsformtion, nd tht is where n overll inrese ws oserved. Ellgitnnins re intimtely relted to stringeny (Glsni & Hoffmn, 2006; Strk et l., 2010; Sáenz-Nvjs, et l., 2012; Mihel et l., 2013). A reent study y Chir nd Teissedre (2014) found 59% orreltion etween higher onentrtions of this ompound nd stringent mouthfeel. Eight ellgitnnins hve een isolted in ok, most ommonly veslgin nd stlgin, nd these orrespond to the mjority of nonflvonoid ompounds (Jkson, 2008). As the wood ges, polymeristion inreses, lthough the proess of tosting tends to hydrolyse the polymers on the ontt surfe, whih is prt of the reson only smll mount of ellgitnnins is found in wines (Jkson, 2008). The profile of extrtile ompounds in trditionl ok woods for ooperge depends on severl ftors, nmely the intrinsi omposition of the wood, whih vries etween speies, origins nd silviulture prmeters, nd the proesses of ooperge nd winemking. It is importnt to understnd whih ompounds n e expeted to e sored y nd extrted from wood, when interting with wines. In omprison with Europen ok woods, Amerin ok is typilly riher in low moleulr weight phenoli ompounds, β-methyl-γ-otltone nd some voltile ompounds, ut poorer in extrtile ellgitnnins (Chtonnet nd Duourdieu, 1998). Besides the inter-speies vritions in omposition nd mehnil properties, there is lso n intrspeies vrition depending on oth origin nd even etween trees, due to silviulture prties, limti onditions nd ltitude. Alñon et l. (2011) found signifint orreltion etween higher ltitudes nd lower onentrtions of voltile ompounds. Amerin ok is lso denser nd more resistnt, with higher porosity. Results otined y Doussot et l. (2002) support tht ok ooperge hoie should not e sed on the wood hrteristis or origin lone, ut on omintion of oth vriles. Q. pyreni hs shown gret results, showing higher romti intensity nd omplexity, s well s more woody, lsmi nd oo roms (Gllego et l., 2012) nd spiiness (Brgnç, 2013) thn Amerin or Frenh oks. A study y Fernández de Simón et l. (2009) ompred voltile ompositions of severl woods, inluding Spnish, Amerin nd frenh ok (Q. pyreni, Q. l nd Q.petre respetively), nd found signifintly higher levels of eugenol in Spnish ok. 22
2.2. Ftors tht ffet wood ontriution nd intertion with wines A few of the min ftors whih determine how wooden ooperge ontriutes to wine geing hve lredy een mentioned, suh s origin of the wood, silviulture prmeters, lotion, limte nd the intrinsi omposition nd grin of the wood type nd speies, ut dditionlly we n onsider heting tretments, ooperge size, whether hips or rrels, oxygen intke, geing time, the presene of lees nd yests nd proper re (rrels nd ellr). 2.2.1 Heting tretments Sesoning nd tosting Sesoning is the proess through whih the woods re dried, stilizing their size, nd lso undergo proess of geing due to rin lehing nd miroil tivity (Chttonet et l., 1994). This n e hieved nturlly or rtifiilly: Nturl sesoning Wood is pled in the open ir, for 2-3 yers, depending on stve size, undergoing intense dehydrtion for the first 10 months, followed y mturtion phse when the wood develops its orgnolepti hrteristis. The intensity nd speed of sesoning vries depending on positioning in the wood pile (Doussot et l., 2002); the middle of the pile is less ffeted y rin or wtering, nd hs onsistently lower humidity rte thn the outer pile (Riéreu-Gyon et l., 2006) Artifiil sesoning Wood uttings re kept in kiln, sumitted to tempertures of 40-60 C, during pproximtely one month (Riéreu-Gyon et l., 2006) Riéreu-Gyon et l. (2006) suggest the wood s humidity should e in onformity with the surrounding tmosphere, pproximtely 14-18% in temperte regions, to ensure struturl stility. Even though onditions re more diffiult to ontrol, nturl sesoning is pointed out s the method providing the est qulity to rrel ged wines, inresing the onentrtion of severl romti ompounds nd reduing itterness nd stringeny onsiderly, when ompred to the rtifiil method, due to the hydrolystion of itter glyosylted oumrins. The results of omprison onduted y Chttonet (1995) found in Riéreu-Gyon et l. (2006) re presented in the tle elow, for Limousin ok in model wine solution (tle 4). Tle 4 - Influene of sesoning method on ok omposition (dpted from Chtonnet, 1995 nd Riéreu- Gyon et l., 2006). Nturl Sesoning Artifiil Sesoning Totl polyphenols (OD 280) 30.4 31.2 Flvnols (mg/l) 0.59 0.56 Ellgitnnins (mg/l) 15.5 17.2 is-β-methyl-otltone(µg/l) 12 0.85 trns-β-methyl-otltone (µg/l) 4.5 0.22 Eugenol (µg/l) 2 0.3 Vnillin (µg/l) 11 0.5 Men of 7 smples; ompounds extrted in dilute lohol medium 23
These results, in onformne with those otined y Spillmn et l. (2004), support tht nturl sesoning hs signifint differene in the extrtion of romti ompounds hrteristi of wood geing, previously mentioned, nd lso higher proportion of the is form of β-methyl-otltone, whih is the most odoriferous ltone (Riéreu-Gyon et l., 2006). Literture is ontrditory in this prmeter; Mg (1989) otined similr onlusions to Chtonnet (1995), represented in tle 4. However, Sefton et l. (1993) found the sme ompounds to derese. Ok is estimted to seson out 10 mm per yer, suffering intense dehydrtion in the first 10 months, followed y mturing proess tht determines its qulity. Rin lehing uses derese in ellgitnnins (Vivs nd Glories, 1996), whih my e prt of the resons why rtifiilly sesoned oks hve shown higher levels of this ompound. Tosting is the next step to onditioning wood efore its use in ooperge. The stves ut from the sesoned wood re then used to ssemle rrels, whih re heted nd tosted, interfering in the orgnolepti ontriutions to wine. Tempertures on the inner surfe of rrels typilly reh round 200 C fter grdul rises for 20-30 minutes, during whih the stves re ent into shpe (heting phse), followed y tosting. Conditions vry etween ooperges, ut three types of tosting re onsidered: light, medium nd hevy. Light tosting onsists of sujeting the surfe to tempertures etween 120-180 C for out 5 minutes; the wood ppers spongy, ut the ellulose strutures remin intt. Medium tosting orresponds to temperture of pproximtely 200 C over 10 minutes, nd hevy tosting hs durtion of over 15 minutes, resulting in surfe tempertures of up to 230 C (Riéreu-Gyon et l., 2006). The generl implitions of tosting re sed on proesses of pyrolysis nd thermohydrolisis, whih ffet the romti omposition of wood. Depending on tosting level, these proesses degrde wood omponents suh s lignin (Srni et l., 1990) hemielluloses nd ellgitnnins, suh s veslgin nd stlgin (Cdhi et l., 2001), whih re esily hydrolysed nd first roken down into ellgi nd then glli ids. Desirly, tosting lso degrdes unsturted ldehydes responsile for the sw-dust off-flvour found in wines ged in new rrels (Chtonnet nd Duourdieu, 1998). Tosting tends to redue the mount of extrtle ellgitnnins, s oserved y Nvrro et l. (2016) who found wine smples ged for 12 months in light tosted ok to hve 3 times higher onentrtion of ellgitnnins when ompred to medium tosts, nd 5 times higher thn in hevy tosted oks, when onsidering Frenh ok. This differene ws slightly smller in Amerin ok, t 2.5 nd 4 times the onentrtion, respetively, onfirming tht there is het degrdtion ffeting extrtle ellgitnnins (Peng et l., 1991). Preeding the tosting proess, ellgitnnin loss n lso our due to rin lehing through the stves during nturl sesoning (Vivs nd Glories, 1996). Light tosting is just enough to end stves, leving nturl woody spet, nd pyrolysis is limited, produing few y-produts (Jkson, 2008). 24
Medium tosting genertes some phenoli nd furnili ldehydes (Nishimur et l., 1983). This onedes tosty flvours due to hemiellulose rekdown nd vnill rosted hrter from lignin derived phenoli. Hevy tosting will egin proess of hrring, hlting or limiting the synthesis of phenoli nd furnili ldehydes, nd insted produing voltile phenols, hrterised y smoky spiy undertones, nd progressively destroying ompounds suh s vnillin (Jkson, 2008). As previously mentioned, tosting will redue extrtle ellgitnnins (Peng et l., 1991; Jordão et l., 2006; Nvrro et l., 2016), s well s vnillin nd syringldehyde levels, whih were found to inrese during tosting, rehing mximum vlues etween 195-215 C, nd then ompletely degrding when tempertures rehed 250 C (merin ok) (Gimenez-Mrtinez et l., 1996). Aording to Jkson (2008) this method is voided in typil winemking, sine ol is responsile for disolouring red wines nd stripping them of some desired roms, ut n e desired in the mturtion of other spirits. 2.2.2. Brrel dimension Wooden rrels ome in mny sizes nd shpes. They re now mostly used for mturing wine with dded omplexity, however smller sizes re lso widely used for fermenttion. The effet of size is intimtely relted with the ontt surfe re etween the wine nd the wooden stves, or hips, in ft, ording to Singleton (1974), there is logrithmi inrese of surfe re with the derese of rrel size. Considering the use of wooden hips, surfe re inreses even more, whih elertes the proess nd influenes ll sorption ehviours from romti ompounds, suh s linlool nd ethyl otnote (Rmirez-Rmirez et l., 2004). From n eonomi stndpoint, lrger rrels llow for more effiient ouption in the winery, however, smller sizes re fvourle for hndling nd quiker mturtion, due to more surfe intertion etween wood nd wine. Using 200-250 litre rrels is most ommon, however mny qulity wines re mtured in lrge ooperge of over 1000 litres. 2.2.3 Oxygen uptke Oxidtion is one of the min onsequenes of mturing wines in wooden rrels, whih re generlly proteted from exessive oxidtion, minly ourring during winemking opertions suh s rking, topping nd smpling. In norml onditions, oxygen uptke during these opertions hs een estimted etween 15 nd 40 ml O2 /litre/yer. Tightly fitted ungs, preferly silione, re importnt to ensure miniml exposure, however the miniml oxidtion ourring during rking is often onsidered desirle, sine it promotes the polymeristion of nthoynins nd tnnins promoting olour stility (Jkson, 2008). Controlled oxidtion ffets the phenoli ontent of wines, ontriuting to more omplex roms, due to odoriferous sustnes extrted from the woods, s well s softer tnnins. Another importnt ftor is the use of new or old rrels; rrel tht hs een used 3 to 5 times will hve redued oxygen uptke, similr to tht whih ours in stinless steel vts (Vivs, 1995). 25
2.2.4 Presene of lees nd yest The presene of olloids, lees, yest wlls nd other inding ompounds is less mentioned in literture, ut hs n importnt role, in oth mturtion nd fermenttion stges in ontt with wood. When wines mture on lees, the relesed mnnoproteins hve the pity of inding with phenoli ompounds in wines nd ellgi tnnins from the wood, reduing their tivity, thus softening stringeny (Chtonnet et l., 1992). When wines mture in wooden rrels, it is essentil to keep ontt with the lees, to serve s redution gent whih helps keep oxidtion in the desired levels, due to their own oxygen onsumption (Feuillt, 1994) without developing oxidtive off-flvours, preserving fruity younger roms (Riéreu- Gyon et l., 2006). Aording to Chtonnet et l. (1992) lees ontriute to limiting wood roms from overpowering the wines, supported y Jiménez Moreno et l. (2007) who lso oserved the inding of lees to ok voltile ompounds, deresing their onentrtion. The sme uthors lso found eugenol, 4-propylguiol, 4-methylguiol, furfurl nd 5-methylfurfurl to hve the highest ffinity with lees. Mnnoproteins re lso thought to id with protein nd trtri stility, y thermos-stilizing the proteins responsile for turidity (Moine-Ledoux nd Duourdieu, (1998), nd they re lso relesed y yest utolysis, long with polyshrides (Feuillt et l., 1989). 2.2.5 Cellr onditions Wooden rrels re kept in ellrs, with reltively low tempertures (16 C) (Riéreu-Gyon et l., 2006). When efore or during fermenttion, rrels should not e ompletely topped to void overflow, insted leving out 10% hedspe (Riéreu-Gyon et l., 2006), nd fter fermenttion is omplete, onsistent topping off is neessry s well s homogenistion of lees nd yest deposits âtonnge. Cellr humidity is lso n importnt ftor, s well s ventiltion. High reltive humidity uses more ethnol to evporte, onsequently lowering loholi strength, while low humidity llows the nturl evportion of wter to exeed tht of ethnol, with n opposite effet. A reltive humidity of 70% is good referene (Mrglit, 2012) where it would e sfe to ssume oth wter nd ethnol evportion re lned, nd the wine should mintin the expeted loholi strength. Ventiltion in the ellr hs key role in the volume tht does evporte during winemking, sine ir movement renews the miro-tmosphere round the rrel surfe where evportion ourred, reting differentil whih promotes further losses. If these preutions re not met nd onditions re negleted, fermenttion is going to e irregulr etween thes nd qulity will derese, s well s produtivity nd profit. 26
2.3. Alterntive wood produts In n effort to enefit from wood effets in wine geing in more eonomilly vile mnner, lterntives hve een found nd studied, nmely wood dusts, stves nd wood hips, previously pproved y the OIV (Oeno Resolution 3/2005) nd oth uthorized nd regulted y the EC (EC Regultion 2165/2005 nd 1507/2006, respetively. Figure 4 - Ok wood lterntives; Smll hips, lrge hips nd dust. Fonte:www.theyhtruwineguide.om/log/2015/2/24/took-or-not-to-ok Aording to Singleton nd Drper (1961), smll ok hips (<1 mm dimeter) llow for the removl of 90% of ll extrtle ompounds within 1 week, whih trnsltes into quiker mrket entrne nd less ostly winery ouption. However, sine the extrtion is severely elerted due to inresed surfe ontt re, some romti ompounds whih typilly result from slow geing my tke longer to pper (Jkson, 2008). Sine inserting these frgments into ontiners will still lk the nturlly ourring oxidtion in rrel geing, miro-oxygention my e employed to etter mimi the effets of the more trditionl method (Pizrro et l., 2014; Oerholster et l., 2015). Without this proess, using hips lone will not produe wine with similr hrteristis to long rrel geing, ut it still proves to e vile nd eonomi lterntive to otin young wines with slight olftory nd gusttive woody notes, similr to those with short rrel geing (3 months) (Orteg-Hers et l., 2010). Del Álmo et l. (2008), when ompring red wines ged in rrels or ontt with wooden lterntives of different ok types, found tht generlly, during the first six months of storge, those ged with stves quired hrteristis tht were intermedite to the wines in rrels or with hips. As ontt time inresed, so did the disrepnies oserved etween rrel ged wines nd vt ged wines (with hips nd stves). This supports the viility of their use for shorter geing periods, sine these hnges lso grew during 2 yer ottled period, nd the wines eme ompletely distinguishle. Frno Aldrén et l. (2007) found nother interesting omprison ftor, oserving tht wines ged in rrels hd up to 5 times the onentrtion of whiskey-ltone, s well s eugenol nd guiol, thn 27
wines ged with hips, while the ltter hd higher levels of vnillin. Gutierrez-Afonso (2002) ompred the sensory effets etween white wine geing in rrels or with hips, nd found tht ok hips, regrdless of speies, hd greter impt on tste (stringeny nd itterness) s well s wood roms (oonut nd vnill). Wood hips re typilly dded in enlosed netted polyester gs to filitte their removl from the ontiners, lthough this limits ompound extrtion due to reduing the ontt surfe with wine. Gllego et l. (2015) studied hip pplition in vrious stges, nd otined similr results. However these still suggested tht performing this ddition during mlolti fermenttion leds to more pronouned effets. They re typilly dded during loholi fermenttion, ut my e pled in finished wines. Using hips s lterntives to rrel geing leds to redued wine losses, eliminting the nturl evportion of the trditionl method nd llows for more effiient ouption of the winery nd etter temperture nd hygiene ontrol, while still onferring woody hrteristis to wine, through short term geing, suh s ok, vnill nd spiy roms, produing different wines with their own ple in the mrket. 2.4. Potentil lterntive wood speies for enology Studying the potentil of lterntive woods for fermenting nd geing wine is reent soure of interest, onsidering minly i (Roini pseudoi), herry (Prunus vium), hestnut (Cstne stiv) nd mulerry (Morus l nd M.nigr), mong others, nd iming t weighing the differenes reltively to ok wood. This helps ssess whether these re vile lterntives, whih my one dy ontriute to their widespred use, in turn ringing innovtion to the wine mrket nd ontriuting to lowering the ok demnd nd its eologil impt. Of these wood types, esides ok, only hestnut is llowed in winemking. 2.4.1. Cherry (Prunus vium) The hertwood of herry wood n rnge from red to reddish rown in olourtion, drkening with time nd light exposure. Similrly to ok, it is stright grin wood, hrterised y medium resistne nd density, s well s low stiffness. In omprison with ok wood, it is riher in lignin derivtives nd poorer in lipids nd rohydrtes (Fernández de Simón et l., 2014). Cherry hertwood hs een found to e more suitle for short term geing, due to elerted phenol oxidtion (De Rosso et l., 2009) nd lower sensory soring for wines ged 6 months nd over in this type of wood (Fernández de Simón et l., 2014). 28
Regrding the phenoli omposition, herry wood hs wide vriety of ompounds, minly onsiderle mounts of (+)-tehin, orresponding to out 90% of the quntified flvnols (Chinnii et l., 2015), ondensed tnnins of the proynidin type nd flvnones (most undntly skurnetin, nringenin nd pinoemrin) (Chinnii et l., 2015; Jordão et l., 2016) whih hve een onsidered txonomi mrkers for dedes. However, nother study hs identified ll of the flvnones mentioned ove, exept for skurnetin (Snz et l., 2012). Although it remins very undnt flvnol in this wood type, importnt omprisons regrding reltive (+)-tehin vlues hve een found. De Rosso et l. (2009) found lowest vlues in herry ged wines, espeilly fter 3 months, in omprison with i, hestnut, mulerry nd ok. Jordão et l. (2016) otined other results, sine in omprison etween herry, i nd 3 types of ok, (+)-tehins were even only quntifile in herry wood smples, lthough, in this se, the wine mtrix ws not ftor. This ompound hs remrkle deteriortion over months of geing, verified y Chinnii et l. (2015), who sw the vlue drop to nerly hlf from 2 to 4 months of geing. In this sme study, even t the 2- month mrk, (+)-tehin vlues were lwys lower in herry thn ok. Gortzi et l. (2013) reported the vlues orrespondent to herry ged wines were only surpssed y (+)- tehin vlues of white mulerry nd priot, whih hve muh less signifint presene in literture, regrding ooperge, however lso onsidering muh lower geing times (10 nd 20 dys). This ompound is not only redued y herry wood s highly oxidtive nture, ut lso y higher tosting levels (Snz et l., 2010). Tosting lso uses derese in hydrolysle tnnins, very hrteristi in ok wood geing, ut with very low presene in herry wood, whih omined with its lk of glli nd ellgi ids nd ellgitnnins estlishes the very different omposition etween herry nd other ooperge woods, suh s ok nd hestnut, s it is mostly omposed of flvnols, flvnones nd ondensed tnnins (Alñón et l., 2011). The presene of the ldehyde p-nisldehyde oth efore nd fter tosting (Fernández de Simón et l., 2009; 2014), unlike in the other studied woods, hs used this to e suggested s mrker of herry wood intertion with wines (Fernández de Simón et l., 2009). Sine it hs een found in other woods in smll mounts, it nnot serve s n solute mrker. Also in omprison with ok, herry wood hs resulted in fster olour stilistion, higher olour density nd generlly etter hromti ttriutes (Chinnii et l., 2011) s well s less vnillin relted roms (vnill, tosty, offee) (Fernández de Simón et l., 2014), typilly ssoited with wood geing, due to reltively smll mounts of this ompound, in oth sesoned nd tosted woods (Fernández de Simón et l., 2009; Jordão et l., 2016). It is importnt to note tht lthough olour my stilise fster, the lk of ellgitnnins nd ellgi id in herry woods will use fster rowning, sine these ompounds re ssoited with reduing oxidtion (Vivs nd Glories, 1996), whih lso supports why, s previously mentioned nd duly ited, herry wood is onsidered highly oxidtive medium nd poorly fitting for long term ging. 29
2.4.2. Ai (Roini pseudoi) Ntive to North Ameri, Roini pseudoi, lso known s flse i, is hrterised y orse grin, with strong irregulr texture, whih ontrsts with ok nd herry (Crvlho, 1997), known for its durility, low porosity nd resistne to insets (Roux nd Pulus, 1962) nd fungus, due to its hertwood s two dominnt flvonoids; roinetin nd dihydroroinetin (Freudenerg nd Hrtmnn, 1953). However, this vries with mturity, sine the dihydroroinetin flvonoid is more undnt in mture hertwood (Sergent et l., 2014). The most undnt flvonoids in i re dihydroroinetin nd roinetin (Roux nd Pulus, 1962;; Snz et l., 2012; Jordão et l., 2016) the ltter eing prtiulrly present fter tosting (Snz et l., 2012). These re onsidered hrteristi to this wood type, sine they were not deteted in oks, hestnut, herry or mulerry (De Rosso et l., 2009; Snz et l., 2010; Jordão et l., 2016). Regrding tnnins, unlike ok nd hestnut whih show n undne of ellgitnnins, nd herry whih minly ontins proynidin types, tnnins of the proroinetin type re dominnt in flse i (Snz et l., 2012). The presene of the phenoli ldehyde 2,4-dihydroxyenzdehyde is onsidered mrker of i intertion with wines over time (Fernández et l. 2009; 2013; 2014; Snz et l., 2012), long with their tnnin profile. Snz et l. (2012) did not quntify this ompound, ut verified the presene of two ldehydes whih ould lso e used s mrkers, sine they were the only ones present even ove medium tosting; glli nd β-resoryli ldehyde. Phenoli mrkers will inrese with geing time, however, due to their onentrtion, it is possile to identify i ged wines s shortly s 2 months of geing (Snz et l., 2012). Vnillin is one of the most relevnt ompounds in wood ged wine, s it is responsile for its typil tosty nd vnill roms. When ompred to herry, hestnut nd ok woods, i hs shown the lowest vnillin vlues (Snz et l., 2012; Fernández et l., 2014) or seond lowest, preeded y herry (Fernández et l.,2009). Jordão et l. (2016) found lower vlues of vnillin in herry nd Amerin ok thn flse i. 2.4.3. Chestnut (Cstne stiv) Chestnut wood ws lwys widely ville nd used in rrels in the Mediterrnen. Moreover, its intertions with wine hve few foused studies. It hs een found to e riher in voltile phenols suh s isoeugenol, guiol nd methylguiol, s well s vnillin nd derivtives, when ompred to trditionl ok woods (Alñon et l., 2012), ut it is lso onsidered to e the most similr to ok when it omes to polyphenoli profile, eing very rih in glli id nd hydrolysle tnnins (Slgoity- Auguste et l., 1987). Its lrger ontent in low moleulr weight phenols inreses its ntioxidnt properties when ompred to ok (Cns et l., 2008). When omined with its tnnin ontent supports 30
why the min use of hestnut in winemking is ommeril tnnin gents to protet musts from oxidtion or improve stringeny (Alñon et l., 2012). De Rosso et l. (2009) ssess hestnut wood s more oxidtive geing medium thn ok, due to its higher porosity nd, onsequently, lower resistne to gseous diffusion. Thus, it my e onsidered less pproprite for long term geing. Alñon et l. (2013) lso dvise ginst long term geing, due to undesirle onentrtions of 4-ethylphenol nd 4-ethylguiol, whih my promote the pperne of off-flvours. 31
3. O j e t i v e o f t h e s t u d y The im of this study ws to evlute the effets of wood hips, prtiulrly ok nd herry, in the phenoli nd sensoril profile of rosé wine, throughout fermenttion nd storge. This should provide ontriution to lking sujet; the use of wood produts in rosé winemking nd the vile use of lterntive woods in order to innovte nd preserve ok resoures whih re lmost exlusively sought for this purpose. To respond to this prtiulr hllenge, severl essys were mde in semi-industril sle, with ollortive reserh work, using Tourig Nionl grpes provided y Cs d Pssrell, where the prodution took ple. In this ontext, the loholi fermenttion of red must from these grpes ws rried out in ontt with herry nd ok wood hips (seprtely), followed y n geing proess of 80 dys, with nd without ontt with the wood hips. 32
4. M t e r i l n d m e t h o d s 4.1. Wine nd wood mterils The wine used in this study is rosé mde in the Cs d Pssrel winery in the Dão Region (Portugl), from Tourig Nionl grpes hrvested in 2016, using diret pressing. Fermenttion ws rried out with no temperture ontrol, in 1000L stinless steel vts, t ellr temperture (20 C). After loholi fermenttion, no fining tretments were mde. Both the must nd wine re inluded in this study. The summry hemil nlysis of this wine n e found elow, in tle 5. Tle 5 Generl hemil nlysis of the wine produed in this study Anlysis rried out y IPViseu. MI methods re internl to the lortory. Vlue Units Method ph 3.04 OIV-MA-AS313-15:R2011 Totl idity 6.82 g trtri id /L MI32-Edição 10 Rev. 1, 2014 Voltile idity 0.27 g eti id /L MI38-Edição 10 Rev.1, 2014 Gluose + frutose < 0.3 g/l MI07-Edição 10 Rev.3, 2016 Surose + gluose + frutose 0.3 g/l MI08-Edição 10 Rev.3, 2016 Totl SO2 151 mg/l MI37-Edição 10 Rev.1, 2014 Free SO2 63 mg/l MI35-Edição 10 Rev.1, 2014 Totl dry extrt 19.8 g/l OIV-MA-AS2-03B:R2012 Aloholi ontent 13.2 % vol MI25-Edição 10 Rev.3, 2016 Copper < 0.10 mg/l MI02-Edição 10 Rev.3, 2016 The wood hips were purhsed from AEB Bioquími Portugues, SA (Viseu), oth Frenh ok (Querus petre) nd herry wood (Prunus vium), with medium dimension (8 mm) nd medium tost. 4.1.1. Experimentl onditions This experimentl work ws onduted on oth must nd wine, unfolding into 3 essys for musts, nd 5 essys for wines. When pplile, the wood hip dosge ws 1,5 g/l in 1000L vinifition vts. Aloholi fermenttion lsted 20 dys, during whih one must ssy hd no ontt with wood hips (CONTROL), nd two ssys were in ontt with herry nd ok wood hips (CH nd OK respetively). Smples were olleted in dys 0, 2, 6, 8, 10 nd 20 of fermenttion. 33
Storge 500L Fermenttion 1000L Regrding the rosé wines produed, the ontrol must remined s ontrol wine, hving no ontt with wood hips. The wood fermented musts were then split fter loholi fermenttion, into two different ssys eh, resulting in the following tegories: CONTROL CHFA CHF OKFA OKF No ontt with wood hips, prior to or post fermenttion; Fermented nd ged in ontt with herry hips; Fermented with herry hips; these were removed fter AF nd not present in geing; Fermented nd ged in ontt with ok hips; Fermented with ok hips; hips removed fter AF nd not present in geing. Wine smples were tken fter 40, 60 nd 80 geing dys. The digrm of the experimentl model is shown in figure 5. Chips Chips Figure 5 Digrm representing the experimentl onditions for this study. Legend: Control: ontrol must nd wine, CH: must fermented with herry hips, OK: must fermented with ok hips, CHFA: wine ged with herry hips, CHF: wine ged without herry hips, OKFA: wine ged with ok hips, OKF: wine ged without ok hips 34