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13. Facilitating green care improvements in viticultureMelita Sternad Lemut, Lorena Butinar, Adesida Rowland, Urban Česnik, Tjaša Jug, Paolo Sivilotti, Urška Vrhovšek, 2019, objavljeni znanstveni prispevek na konferenci Opis: The growing demand of consumers for environment-friendly and safe food products already forced many winemakers to restrict the application of synthetic fungicides to earlier season, trying to reduce the risk of residues being detected in wines. Main risk for infection by B. cinerea, however, occurs later in the season. To support an improvement in whole-season B. cinerea green care, the potential of yeasts as biocontrol agent (PBA) was studied. Selected yeasts were tested for their antifungal activities. Furthermore, a field experiment in Pinot noir and Pinot gris vineyards was designed to study different combinations of optimized canopy microclimate manipulation (CMM) techniques and PBA application. In experimental conditions, PBA's ability to maintain appropriate population density for disease prevention was observed. Grape and wine quality parameters were evaluated. Analytical approach of metabolomics was applied to upgrade the understanding of potentially induced changes in plant metabolism.
Based on yeasts testing results, biocontrol yeast P. guilliermondii ZIM 624 was selected and after its field application, we were able to detect its suitable density on grapes until harvest. In case of early defoliation for both varieties smaller grape compactness was confirmed together with lower yield. Among grape basic quality parameters, optimized techniques showed positive effect on sugar content, but unexpectedly, in the treatments with biocontrol yeasts the trends toward higher acidity were noticed in Pinot gris. CMM and PBA introduction indicated some effects on grapevine biosynthetic behaviour but the differences in content of these metabolites compared to control were poorly detected in final wines with exception of mainly some flavonols, stilbenes and flavan-3-ols (and consequently total phenolic content).
Ključne besede: sustainable viticulture, Botrytis cinerea, yeasts, biocontrol, canopy microclimate manipulation, metabolomics, grapevine metabolites
Objavljeno v RUNG: 28.02.2020; Ogledov: 3813; Prenosov: 0
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15. Analiza kakovostne in ekonomske upravičenosti vpeljave tehnološkega postopka predfermentativne maceracije v predelavi grozdja sorte 'Refošk'Marko Benčina, 2019, magistrsko delo Opis: V magistrskem delu smo obravnavali kakovostno in ekonomsko upravičenost vpeljave tehnološkega postopka hladne predfermentativne maceracije, s katerim smo želeli izboljšati predvsem barvne in aromatične lastnosti vina 'Refošk'. Najprej smo razložili pomen investicij in metode, s katerimi investicije ocenjujemo. V praktičnem poskusu smo pridelali vino po postopku hladne predfermentativne maceracije (HPM), za primerjavo pa smo vino pridelali še po postopku klasične fermentativne maceracije (FM) in fermentativne maceracije pri višji temperaturi (FMVT). V pridelanih vinih smo določali skupne polifenole, skupne in posamezne antocianine, barvo vina ter izvedli senzorično analizo. V ekonomskem delu smo ugotovili, kako bi investicijo financirali, in definirali lastno ceno. S pragom rentabilnosti smo predvideli smotrno prodajno ceno ter z metodami denarnih tokov in sedanje vrednosti ugotovili, da bi se nam investicija povrnila v devetem letu poslovanja. Rezultati kažejo, da je hladna predfermentativna maceracija vplivala na značilno večjo vsebnost skupnih polifenolov, medtem ko smo opazili značilno večjo vsebnost skupnih antocianinov pri FM in FMVT. Uporabljeni tehnološki postopki niso pokazali značilnega vpliva na povečanje vsebnosti posameznih antocianinov, malvidin-3-glukozida ter intenzitete in tona barve vina. Vino, pridelano po postopku HPM, je v primerjavi s FM in FMVT vini na senzorični analizi in testu všečnosti doseglo najmanj točk.
ANALIZA KAKOVOSTNE IN EKONOMSKE UPRAVIČENOSTI VPELJAVE TEHNOLOŠKEGA POSTOPKA
PREDFERMENTATIVNE MACERACIJE V PREDELAVI GROZDJA SORTE 'REFOŠK'
MAGISTRSKO DELO
Marko Benčina
Mentorja: doc. dr. Melita Sternad Lemut, dr. Jan Reščič
Nova Gorica, 2019
ZAHVALA
Iskreno se zahvaljujem vsem, ki ste mi kakorkoli pomagali pri opravljanju teoretskega, eksperimentalnega in analitskega dela magistrske naloge, še posebej dr. Janu Reščiču in Jeleni Topić Božič, mag. ind. farm., za njuno potrpežljivost in pomoč pri laboratorijskem in analitskem delu.
Posebna zahvala tudi mentorici doc. dr. Meliti Sternad Lemut, univ. dipl. inž. živ. tehnol. In somentorju Silvestru Vončini, univ dipl. ekon. za pomoč pri pisanju ekonomskega dela naloge.
Brez Vas ne bi uspelo!
NASLOV
Analiza kakovostne in ekonomske upravičenosti vpeljave tehnološkega postopka predfermentativne maceracije v predelavi grozdja sorte 'Refošk'
IZVLEČEK
V magistrskem delu smo obravnavali kakovostno in ekonomsko upravičenost vpeljave tehnološkega postopka hladne predfermentativne maceracije, s katerim smo želeli izboljšati predvsem barvne in aromatične lastnosti vina 'Refošk'. Najprej smo razložili pomen investicij in metode, s katerimi investicije ocenjujemo. V praktičnem poskusu smo pridelali vino po postopku hladne predfermentativne maceracije (HPM), za primerjavo pa smo vino pridelali še po postopku klasične fermentativne maceracije (FM) in fermentativne maceracije pri višji temperaturi (FMVT). V pridelanih vinih smo določali skupne polifenole, skupne in posamezne antocianine, barvo vina ter izvedli senzorično analizo. V ekonomskem delu smo ugotovili, kako bi investicijo financirali, in definirali lastno ceno. S pragom rentabilnosti smo predvideli smotrno prodajno ceno ter z metodami denarnih tokov in sedanje vrednosti ugotovili, da bi se nam investicija povrnila v devetem letu poslovanja. Rezultati kažejo, da je hladna predfermentativna maceracija vplivala na značilno večjo vsebnost skupnih polifenolov, medtem ko smo opazili značilno večjo vsebnost skupnih antocianinov pri FM in FMVT. Uporabljeni tehnološki postopki niso pokazali značilnega vpliva na povečanje vsebnosti posameznih antocianinov, malvidin-3-glukozida ter intenzitete in tona barve vina. Vino, pridelano po postopku HPM, je v primerjavi s FM in FMVT vini na senzorični analizi in testu všečnosti doseglo najmanj točk. Na podlagi dosežene kakovosti in ekonomskih ocen smo sklenili, da bi bila investicija v postopek HPM v proučevanem letu ekonomsko manj upravičena.
Ključne besede: Investicija, vrednotenje investicij, lastna cena, hladna predfermentativna maceracija, antocianini, barva vina, Vitis vinifera L. cv. 'Refošk'
Objavljeno v RUNG: 23.05.2019; Ogledov: 4797; Prenosov: 180
 Celotno besedilo (2,04 MB) |
16. Reception of foreign women writers in the Slovenian literary system of the long 19th century2017, znanstvena monografija Opis: The first chapter illustrates the extent of the perception of foreign women writers in the Slovenian ethnic territory. Many names and works of women writers were found in Slovenian periodicals and libraries. In addition to identifying intertextual connections, Tanja Badalič argues that interesting dynamics of literary perception were also a characteristic of Slovenian literature of that time. The second chapter is dedicated to research into the influence of the controversial writer Laura Marholm and the principal Slovenian modernist Zofka Kveder. Katja Mihurko Poniž concludes that the reception of Laura Marholm was as ambivalent as her book, which became evident in the analysis of the reception of another writer, Zofka Kveder herself. The third chapter illustrates the possibilities of visualisation of information from the virtual research environment VRE Women Writers. In their contribution, Aleš Vaupotič and Narvika Bovcon explain how students at the Faculty of Computer and Information Science, University of Ljubljana, designed different visualisations and thereby reflect the relation between a literary scholar, a graphic designer and a computer engineer. With the approach of distant reading we discovered many forgotten names; but a complete picture also required close reading, which revealed specifics of the reception that would have otherwise remained unclear.
Objavljeno v RUNG: 15.01.2019; Ogledov: 3019; Prenosov: 37
Celotno besedilo (10,46 MB)
Gradivo ima več datotek! Več... |
17. VPLIV ODTRANJEVANJA LISTOV IN UPORABE MREŽ ZA ZAŠČITO PRED PTIČI NA KOLIČINO PRIDELKA TER KAKOVOSTNE PARAMETRE GROZDJA IN VINA SORTE SAUVIGNONASSE (VITIS VINIFERA L.)Aljaž Namar, 2018, diplomsko delo Opis: Odstranjevanje listov v območju grozdov in uporaba mrež za zaščito pred ptiči sta pogosto uporabljeni vinogradniški strategiji, ki vplivata na mikroklimatske pogoje v grmu vinske trte ter posledično na količinske in kakovostne parametre pridelka. V okviru diplomskega dela smo v vinogradu sorte 'Sauvignonasse' v Pristavem (Brda), po načelu naključne razporeditve blokov trt, zastavili primerjavo med petimi ukrepi: UNT (brez tretiranja), ELR (razlistanje pred cvetenjem), LLR (razlistanje po cvetenju), REN (razlistanje po cvetenju in senčenje z rdečimi mrežami) ter BKN (razlistanje po cvetenju in senčenje s črnimi mrežami). Tekom dozorevanja smo v odvisnosti od ukrepa spremljali osnovne kakovostne, ob trgatvi pa tudi količinske parametre pridelka. Grozdje smo ločeno vinificirali in v vinih določili osnovne kakovostne parametre, vsebnost hlapnih tiolov ter opravili senzorično analizo. Z obravnavanimi ukrepi smo le v manjši meri vplivali na kakovostne parametre grozdja, medtem, ko smo, predvsem z ukrepom ELR, pomembneje vplivali na količino pridelka in težo grozdov. V vinih smo (v korist obravnavanjem ELR, LLR in REN) opazili razlike v koncentracijah sladkorja prostega ekstrakta, poleg različnih trendov vsebnosti skupnih titracijskih kislin pa smo z ukrepi povzročili tudi nekaj razlik v vsebnostih posameznih kislin (vinska, jabolčna) ter skupnih hlapnih kislin. V primerjavi s kontrolo smo opazili povečanje vsebnosti 4MMP pri obravnavnjih BKN in ELR ter povečanje 3MH pri LLR, BKN in REN. Natančnejši pregled povzročenih sprememb in rezultatov (enoletnih) primerjav je nakazal, da učinki na opazovane parametre niso tako preprosti in linearni, da bi omogočili sistematično optimizacijo oz. da so medsebojni vplivi različnih kombinacij vinogradniških strategij na parametre grozdja kompleksni ter jih moramo uvajati nadvse previdno.
Ključne besede: 'Sauvignonasse' (Vitis vinifera L.), odstranjevanje listov v območju grozdov, mreže za zaščito pred priči, mikroklima, osnovni količinski in kakovostni parametri grozdja in vina, hlapni tioli.
Objavljeno v RUNG: 06.03.2018; Ogledov: 6223; Prenosov: 217
Celotno besedilo (1,12 MB) |
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19. BIOTSKA RAZNOVRSTNOST KVASOVK POVEZANIH S PROIZVODNJO JABOLČNEGA VINAEivind Vangdal, Melita Sternad Lemut, Branka Mozetič Vodopivec, Lorena Butinar, 2017, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Na območju fjorda Hardanger, del zahodne Norveške, ima proizvodnja jabolčnega vina dolgo tradicijo in sicer sega v 12. stoletje, ko so menihi na tem območju začeli uvajati sadjarstvo. Danes je to glavno območje pridelovanja sadja na Norveškem. Kljub strogi regulativi proizvodnje alkoholnih pijač, pa se je na tem območju na nekaterih kmetijah ohranila tradicionalna proizvodnja jabolčnega vina. Namen naše študije je bil predvsem preučiti ekologijo in biotsko raznovrstnost kvasovk, ki so povezane s proizvodnjo tradicionalnega jabolčnega vina na območju Hardanger. Na tem območju smo tekom dveh zaporednih let vzorčili na 11-ih različnih lokacijah, kjer smo pri proizvajalcih vzorčili jabolčno vino, tla in različne dele jablan v sadovnjakih. Tako smo s pomočjo bogatitve v gojišču s povišanim sladkorjem in etanolom osamili približno 1300 izolatov kvasovk. Kvasovke smo s pomočjo multipleks PCR testa ločili na skupino kompleksa Saccharomyces sensu stricto in ne-Saccharomyces kvasovke. Nadalje smo izolate določili do nivoja vrste z izvedbo restrikcijske analize ITS PCR produktov, v nekaterih primerih smo za potrditev identifikacij opravili še določitev nukleotidnih zaporedij D1/D2 domene 26S rDNA. Kot pričakovano smo ugotovili, da sadovnjake naseljujejo predvsem ne-Saccharomyces kvasovke iz rodov Metschnikowia in Hanseniaspora, v tem okolju so bile Saccharomyces izolirane iz tal in jabolk. V jabolčnem vinu pa je bila pretežno izolirana vrsta S. uvarum, občasno pa tudi S. cerevisiae, Torulaspora delbrueckii in P. membranifacies.
Ključne besede: kvasovke, biotska raznovrstnost, jabolčno vino
Objavljeno v RUNG: 09.11.2017; Ogledov: 5224; Prenosov: 0
Gradivo ima več datotek! Več... |
20. Biodiversity of cider yeasts and their cider-making potentialEivind Vangdal, Melita Sternad Lemut, Branka Mozetič Vodopivec, Lorena Butinar, 2017, objavljeni povzetek znanstvenega prispevka na konferenci Opis: In the area of Hardanger, a part of the fjord region in Western Norway, the production of apple wine (cider) has a long tradition that goes back to the 12th century, when monks introduced apple growing in this area. Nowadays, this is also the main area of fruit production in Norway. Despite the strict regulation of the alcoholic beverage production in Norway, traditional cider is still produced on some farms in this area. By tradition cider is produced by a spontaneous fermentation process of apple juice, performed by naturally occurring indigenous yeasts that originate from the fruit or the surfaces of the processing equipment. Therefore, our aim was primarily to study the ecology and biodiversity of the yeasts associated with the production of traditional cider in the Hardanger area. For two consecutive years, we sampled at 11 different locations in the observed region, where we collected cider samples and surface swabs of processing facilities from the cideries, and also soil and various parts of apple trees in orchards owned by the same producers. Thus, by enriching collected samples with the selective medium with high sugar and ethanol concentration, we managed to isolate about 1,300 yeasts. Based on the multiplex PCR results the yeasts were grouped into the Saccharomyces sensu stricto complex and non-Saccharomyces yeasts. The isolates were determined to the species level by performing the restriction analysis of ITS PCR products, and in some cases identifications were confirmed by sequencing of the D1/D2 domain of the 26S rDNA and/ or ITS region. As expected, non-Saccharomyces yeasts from the genus Metschnikowia and Hanseniaspora mainly populated the orchards, while the Saccharomyces yeasts were isolated in the orchards from the soil and fruits. In contrast, in ciders the species S. uvarum was predominantly found, occasionally also S. cerevisiae, Torulaspora delbrueckii and P. membranifacies. Indigenous cider yeasts were further on characterized in micro-plate format for the most important cider-making technological parameters (tolerance to ethanol, SO2, growth at low pH), for the presence of glucoside hydrolase activity, H2S production ability, and assimilation of malic acid. Based on this screenings the micro-scale fermentations of apple juice were performed with 13 different indigenous cider yeasts as monocultures. The most promising indigenous yeasts, T. delbrueckii and S. uvarum, were also tested as mixed cultures in sequential fermentations. Since the tested strain of T. delbrueckii as monoculture was not able to complete the alcoholic fermentation, better results were obtained in sequential fermentation with the mixed culture in combination with S. uvarum.
Ključne besede: indigenous yeasts, biodiversity, spontaneous fermentation, cider-making
Objavljeno v RUNG: 08.11.2017; Ogledov: 6160; Prenosov: 0
Gradivo ima več datotek! Več... |
