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Title:VPLIV SONČNEGA OŽIGA IN DEHIDRACIJE GROZDJA V POZNEM DOZOREVANJU NA KAKOVOST GROZDJA (Vitis vinifera L.) IN VINA SORTE 'BARBERA'
Authors:ID Šuklje, Katja (Mentor) More about this mentor... New window
ID Reščič, Jan (Mentor) More about this mentor... New window
ID Cotič, Kristina (Author)
Files:.pdf Kristina_Cotic.pdf (2,29 MB)
MD5: D534D54B888F896A7BF61E0768024964
 
Language:Slovenian
Work type:Bachelor thesis/paper
Typology:2.11 - Undergraduate Thesis
Organization:VŠVV - College of Viticulture and Enology
Abstract:Venenje ali dehidracija grozdja opisuje nepovratno in progresivno izgubo vode v grozdni jagodi, opisuje izgubo vode iz parenhimskih celic v mesu jagode. Spremembe zaradi dehidracije so opazne v velikosti, masi ter zunanjemu izgledu jagode. V diplomskem delu smo želeli preučiti vpliv dehidracije in sončnih ožigov v poznem dozorevanju na nekatere količinske in kakovostne parametre grozdja in vina sorte 'Barbera' (Vitis vinifera L.). Grozdne jagode smo ustrezno razdelili na dve skupini, na dehidrirane in nedehidrirane. Vpliv dehidracije grozdnih jagod na kemične in senzorične parametre smo preučevali z mikro-vinifikacijo v treh ponovitvah. Rezultati našega poskusa kažejo, da dehidracija v poznem dozorevanju vpliva na količino in kakovost grozdja in vina sorte 'Barbera' (Vitis vinifera L.). Ugotovili smo, da je bil primaren vzrok izgube mase jagod dehidracija grozdnih jagod v poznem dozorevanju in ne sončni ožig. Dehidracija jagod je značilno zmanjšala maso svežih jagod, kar je posledično vplivalo na manjši pridelek. Večjo vsebnost topne suhe snovi smo določili v grozdnem soku iz dehidriranih jagod. Prav tako smo v grozdnem soku iz dehidriranih jagod izmerili višje titrabilne kisline. Stopnja alkohola je bila višja v vinih, pridelanih iz dehidriranih jagod. Vina so se razlikovala tudi po vsebnosti skupnih antocianov, ti so bili višji v vinih iz dehidriranih jagod kar sovpada z izmerjenimi podatki o višji vsebnosti skupnih polifenolov v vinu iz dehidriranih jagod. Razlike smo opazili tudi v intenziteti barve vina, katera je bila višja v vinih iz dehidriranih jagod, medtem ko je bil odtenek barve višji v vinih iz nedehidriranih jagod. Senzorična analiza pridelanih vin je pokazala, da so bila vina, pridelana iz dehidriranih jagod, ocenjena kot bolj sadna (rdeče in temno sadje) in manj zelena, čeprav razlike niso bile statistično značilne. Dehidracija grozdnih jagod v poznem dozorevanju je vplivala na pridelek, vsebnost topne suhe snovi in skupnih kislin v grozdju ter značilno vplivala na alkohol in barvne parametre vina. Razlike v senzorični zaznavi so bile manj izrazite.
Keywords:dehidracija jagod, sončni ožig, Vitis vinifera L. 'Barbera', indeks dehidracije, mikro-vinifikacija, kemijski parametri vina, antociani, senzorika vina
Place of publishing:Nova Gorica
Year of publishing:2019
PID:20.500.12556/RUNG-4754-2d4f5049-181a-9267-32ff-abe626eb2952 New window
COBISS.SI-ID:5461499 New window
NUK URN:URN:SI:UNG:REP:4PFP2F16
Publication date in RUNG:14.10.2019
Views:5712
Downloads:174
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Secondary language

Language:English
Title:Impact of sunburn and grape dehydration in late ripening on the quality of 'Barbera' (Vitis vinifera L.) grape and wine
Abstract:Berry shrivelling or dehydration of grape describes an irreversible and progressive loss of the water in grape berries, it describes the loss from parenchymatic cells in the flesh of grape. Dehydration in our experiment was observed as a berry fresh weight loss and as visual modifications in appearance of the berries. In this work we intended to study the influence of dehydration and sunburn in the later ripening on the quantitative and qualitative parameters of 'Barbera' (Vitis vinifera L.) grapes and wine. Grape berries were appropriately classified into two groups, dehydrated and non-dehydrated berries. The effect of grape berry dehydration on wine chemical and sensory parameters was studied by performing micro-vinifications in triplicates. The results of our experiment show that dehydration in late ripening affects the quantity and quality of 'Barbera' (Vitis vinifera L.) grape and wine. We found out that the primary cause of observed weight loss and shrivelling in our study was dehydration in late ripening and not sun burns. Berry dehydration resulted in significant decrease in berry fresh weight, consequently influencing lower yields. Total soluble solids were higher in grape juice from dehydrated berries. We also found higher total acids in grape juice from dehydrated berries. Alcohol levels were higher in wines made from dehydrated berries. Wines also differed in the content of total anthocyanins which were higher in wines made from dehydrated berries coincidencing also with higher total polyphenols. The differences were also observed in the color intensity of wine which was higher in wines made from dehydrated berries, whereas hue was higher in wines made from non-dehydrated berries. The sensory analysis of the produced wines showed that wines from dehydrated berries were judged as fruitier (red and dark fruit) and less green, however the differences were not statistically significant. Berry dehydration in late ripening influenced yield, total soluble content and total acidity in grapes and also had significant influence on wine alcohol and colour parameters. The differences in wine sensory were less pronounced.
Keywords:berry dehydration, sunburn, Vitis vinifera L. 'Barbera', shrivelling index, micro-vinification, chemical parameters of wine, anthocyanins, wine sensory


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