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Eivind Vangdal, Melita Sternad Lemut, Branka Mozetič Vodopivec, Lorena Butinar, 2017, published scientific conference contribution abstract

Abstract: 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.
Keywords: kvasovke, biotska raznovrstnost, jabolčno vino
Published in RUNG: 09.11.2017; Views: 5652; Downloads: 0
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Biodiversity of cider yeasts and their cider-making potential
Eivind Vangdal, Melita Sternad Lemut, Branka Mozetič Vodopivec, Lorena Butinar, 2017, published scientific conference contribution abstract

Abstract: 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.
Keywords: indigenous yeasts, biodiversity, spontaneous fermentation, cider-making
Published in RUNG: 08.11.2017; Views: 6540; Downloads: 0
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The comparison of anthocyanin and pyranoanthocyanin extraction efficiency in Pinot Noir wine using SPE
Jelena Topic, Dorota Korte, Branka Mozetič Vodopivec, 2017, published scientific conference contribution abstract

Keywords: Anthocyanins, wine, Pinot Noir, HPLC, solid-phase extraction
Published in RUNG: 05.07.2017; Views: 5562; Downloads: 0
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Združevanje vinarjev Vipavske doline v konzorcij.
Tomaž Vodopivec, 2016, undergraduate thesis

Keywords: Trženje vin, blagovna znamka, Vipavska dolina, konzorcij vinarjev, trženjska strategija
Published in RUNG: 23.05.2017; Views: 5606; Downloads: 286
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Phenolic Contents and Postharvest Quality Changes of Norwegian ‘Mallard’ plums (Prunus domestica L.) as a Consequence of Delayed Time to Low Temperature Storage : /
Branka Mozetič Vodopivec, Alena Gibalova, Eivind Vangdal, 2012, published scientific conference contribution

Abstract: During the picking season in the Norwegian plum production areas, the harvested plums are brought to cold storage in packing houses once or twice a day. Plums picked late in the afternoon may even not be cooled properly until the next day. The average time from picking until the plums are placed in a cold storage is approximately 8 hours. Previous reports have shown that delayed cooling of sweet cherries and apples reduced the fruits’ susceptibility to physiological or fungal decay. An experiment was performed in order to evaluate the impact of different delay-to-cold storage times (0, 5, 10, 15 and 25 hours) on quality and phenolic contents changes of Norwegian ‘Mallard’ plums during cold storage, transport, and retail in normal atmosphere (NA). The fruits (10 fruits in PE tray, n=3) were stored for 14 days at 1°C, followed by 3 days at 7°C and then for 4 days at 20°C. Fruit quality parameters (firmness, colour in CIE L, a*, b* colour space, weight, rot occurrence (%)) and total phenol and anthocyanin content were determined. Samples were analyzed just before cold storage and then after 14 days at 1°C, 3 days at 7°C, or 4 days at 20°C. Evaluation of results has shown that delay of cooling has a retarding effect on rot development during 20°C storage (post cold transport), weight loss and stimulates anthocyanin accumulation and colour changes to some extent. At the end of storage no effect on fruit firmness could be observed.
Keywords: anthocyanins, total phenols, colour, rot, firmness, postharvest, plums, cold storage
Published in RUNG: 11.11.2016; Views: 4912; Downloads: 0
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Determination of bioactive compounds in food samples by thermal lens microscopy
Jelena Topić, Mojca Žorž, Valeria Guzsvány, Branka Mozetič Vodopivec, Dorota Korte, Mladen Franko, 2016, published scientific conference contribution abstract

Keywords: thermal lens microscopy, food samples, bioactive compounds
Published in RUNG: 08.11.2016; Views: 5775; Downloads: 0
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Polyphenol, antioxidant and antimicrobial potential of six different white and red wine grape processing leftovers : /
Kajetan Trošt, Anja Klančnik, Branka Mozetič Vodopivec, Melita Sternad Lemut, Katja Jug, Peter Raspor, Sonja Smole Možina, 2016, original scientific article

Abstract: BACKGROUND During winemaking, grape polyphenols are only partly extracted, and consequently unexploited. The main aim was to characterise the phenolic content of freeze-dried grape skin and seed (FDSS) extracts obtained from Slovenian and international grape varieties and evaluate their antioxidant, antimicrobial, and anti-adhesive activities. RESULTS FDSS of six Vitis vinifera L. grapevine cultivars from Vipava Valley region (Slovenia) underwent extraction and sonification under different conditions. Flavonols were the predominant content of extracts from white ‘Zelen’ and ‘Sauvignon Blanc’ grape varieties, with strong antimicrobial activities against Gram-negative bacteria. ‘Pinot Noir’ FDSS extracted with 50% aqueous ethanol extraction produced a high phenolic content in the final extract, which was further associated with strong antioxidant and antimicrobial activities against all tested bacteria. Bacterial adhesion to stainless steel surfaces with minimal and maximal surface roughness was significantly inhibited (up to 60%) across a wide FDSS concentration range, with lower concentrations also effective with two types of stainless steel surfaces. CONCLUSION FDSS extracts from winery by-products show interesting phenolic profiles that include flavonols, catechins, anthocyanins, and hydroxycinnamic acids, with yields influenced by grapevine cultivar and extraction conditions. The antioxidant, antimicrobial and anti-adhesive activities of 50% aqueous ethanol ‘Pinot Noir’ FDSS extract reveals potential applications in food, pharmaceutical and cosmetic industries for these bioactive residues.
Keywords: grape skins and seeds, extraction solvents, phenolic profile, antioxidant activity, antimicrobial activity, anti-adhesion activity to stainless steel
Published in RUNG: 08.08.2016; Views: 5386; Downloads: 0
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Karmen Bizjak Bat, 2016, doctoral dissertation

Abstract: Determination of food authenticity is an important issue in quality control and food safety. Recent studies predict a growing demand for natural and more authentic food and beverage products. The quality and authenticity of apple juice is also of a great economic importance since the popularity and demand for apple juice consumption has increased. The growth of the market for organically produced apples and apple juice is due to the increasing demand for healthy food requirements, protection of the environment and the promotion of biotic diversity. Organic foods have a higher nutritional and health value, but they are more expensive, because their production is more difficult and less profitable. In addition to how food is produced, consumers are increasingly placing emphasis on food products of specific region, which are known for their unique natural flavours and taste. The presented thesis is based on four separate but closely interrelated studies, in which a combination of different isotopic ratios of bioelements (2H/1H, 13C/12C, 15N/14N, 18O/16O), multi-element analysis, and major primary and secondary metabolite profiles were exploited to differentiate the geographical origin and agricultural production practice (organic vs integrated/conventional) of Slovenian apples. These parameters were used to establish the first database of authentic Slovenian apple juice, which can be used to verify the authenticity of commercially available apple juice in Slovenia. The first preliminary study was entitled “Organic Cultivation ~ Geographical Origin (OCGO)” and was performed using apples from the 2009 growing season. Its aim was to examine the use of stable isotope and multi-element data for determining the geographical origin and agricultural production practice of fresh apple juices. Fruits of six apple (Malus domestica Borkh) cultivars (Topaz, Idared, Golden Delicious, Goldrush, Gala, Gloster) were collected from four different geographical regions of Slovenia (Alpine, Dinaric, Pannonian and Mediterranean) grown under organic and integrated/conventional orchard management systems. The results revealed that stable isotope parameters in sugar, pulp and water were the most significant variables for differentiating between the regions. Good separation was achieved between the geographical regions in Slovenia based on the δ18O and δ2H values in water and Rb and S levels in the apple fruit juice. The most significant variables that distinguished between organically and integrated/conventionally cultivated apples were the 15N/14N ratio and antioxidant activity of the apple juice. Significant differences were also observed in the ascorbic acid content of the juice. Based on these results the number and types of apples and the minimum number of samples needed from the same region for determining geographical origin were determined. The second study was called “Organic ~ Conventional Apple Cultivation” (OCAC) and was performed in 2010 and 2011 in a Gala apple orchard. The aim was to determine the effect of different fertilizers allowed either in organic or conventional/integrated agricultural regimes on different parameters. Quality parameters, isotopic composition of C in sugars and in pulp together with N and elemental analysis were investigated. The following five fertilizers were applied: Biosol and Plantella organic (organic) and Ca cyanamide, KAN and UREA (mineral) at a rate of 60 and 120 kg of nitrogen per hectare. From the obtained data it was possible to differentiate between organic and integrated/conventional apple production when taking into account the following parameters: mass, skin and flesh firmness (SFF), total soluble solids (TSS), and the content of Cl as well as δ15N and δ13C in the pulp. The “Organic Cultivation ~ Geographical Origin” (OCGO) study, which took place during the 2011 and 2012 growing seasons included a greater number of samples and samples from five different geographical regions: Alpine, Dinaric,
Keywords: apple juice, geographical origin, agricultural production practice, biomarkers, phenol compounds, elements, stable isotopes, Slovenia
Published in RUNG: 07.06.2016; Views: 8306; Downloads: 904
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Isotopic and elemental characterisation of Slovenian apple juice according to geographical origin: Preliminary results : /
Karmen Bizjak Bat, Klemen Eler, Darja Mazej, Branka Mozetič Vodopivec, Ines Mulič, Peter Kump, Nives Ogrinc, 2016, original scientific article

Abstract: This study examined the applicability of stable isotope and multi-element data for determining the geographical origin of fresh apple juices. Samples included three apple cultivars (Idared, Golden Delicious and Topaz) harvested in 2011 and 2012 from five different geographical regions of Slovenia. Regional discrimination of the juice samples was most successful when using linear discriminant analysis (LDA) and taking into account the following parameters: d2H and d18O content of juice water; d15N and d13C content of the pulp, (D/H)I and (D/H)II in ethanol and the concentration of S, Cl, Fe, Cu, Zn and Sr. Overall prediction ability was 83.9%. The factors that best distinguished the different types of cultivar were the d2H and d18O content of fruit juice water; the d13C and (D/H)I content of ethanol; and the concentration of S, Mg, K, Cu, and Ti. Prediction ability, taking into account all ten parameters, was 75.8%.
Keywords: Apple juice, Stable isotopes, Elemental content, Geographical origin, Slovenia
Published in RUNG: 15.02.2016; Views: 6328; Downloads: 0
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Daniela Markovic, 2016, undergraduate thesis

Abstract: Z odstranjevanjem listov v predelu grozdov se lahko spremeni mikroklima grozdov, ki lahko izzove spremembe v sekundarnem metabolizmu vinske trte, ki so odvisne tudi od časa izvedbe ukrepa. Uravnavanje sinteze aromatskih komponent je zanimivo pri belih sortah kot je sorta 'Sauvignon blanc', kjer so metoksipirazini in tioli tisti, ki oblikujejo značilno aromo vina te sorte. Eksperiment diplomske naloge smo zastavili na Oslavju (Gorica, Italija) v vinogradu sorte grozdja 'Sauvignon blanc' (Vitis vinifera L.). Želeli smo preveriti vpliva odstranjevanja listov v predelu grozdja pred in po cvetenju na količino in kakovost pridelka ter aromatske lastnosti grozdja in vina. Količinski parametri pridelka so pokazali majhne vplive izvedenih ukrepov razlistanja; pozno razlistanje na količino pridelka ni vplivalo, v nasprotju z razlistanjem pred cvetenjem, kjer smo opazili rahlo zmanjšanje pridelka po trsu in mase grozdov. Tudi pri osnovnih zrelostnih parametrih smo opazili manjše spremembe, predvsem večje vsebnosti topne suhe snovi pri razlistanju pred cvetenjem. Pri aromatskih komponentah smo zaznali vpliv razlistanja pred cvetenjem na količino prekurzorjev tiolov tako v grozdju kot tudi vinu; večjo vsebnost 4-merkapto-4-metilpentan-2-on (4MMP) in nižje koncentracije 3-merkaptoheksan-1-ol (3MH). S poznejšim odstranjevanjem listov smo zmanjšali koncentracije 4MMP, na vsebnost 3MH ta ukrep ni vplival. Tudi s senzorično oceno vina smo potrdili pomembne vplive razlistanja pred in po cvetenju na določene note v aromi vina 'Sauvignon blanc'. Leaf removal changes cluster microclimate, and thus modifications in the secondary metabolism are triggered, but differently as regard to the timing of application. In case of white grape varieties, the interest on the modification of aroma characteristics is searched, and in case of 'Sauvignon blanc', the shift in concentration of methoxypyrazines and thiols is responsible for the bouquet of the wines. An experimental trial was set up in Oslavia (Gorizia, Italy) with the aim to evaluate how pre-flowering and post-flowering leaf removal applied on 'Sauvignon blanc' vines could change the aromatic occurrence in grapes and wines. The yield parameters were slightly affected by the treatments of leaf removal; while late leaf removal did not impact on production, pre-flowering leaf removal slightly promoted a reduction on yield and cluster weight. Also basic maturation parameters were slightly changed, mainly higher soluble solids in case of pre-flowering leaf removal. As regard aromatics, both thiol precursors in grapes and thiols in wines revealed to be shifted in case of pre-flowering leaf removal, with higher values of 4-mercapto-4-methyl-pentan-2-one and lower values of 3-mercaptohexan-1-ol. In case of late leaf removal lower concentration of 4MMP were revealed and similar of 3MH. Also the degustation of the wines revealed some peculiarities of pre-flowering and late leaf removal treatments for some important sensorial notes of 'Sauvignon blanc' wines.
Keywords: Vitis vinifera L. cv. 'Sauvignon blanc', razlistanje pred cvetenjem, razlistanje po cvetenju, aromatske komponente, tioli, LC-MS Vitis vinifera L. cv. 'Sauvignon blanc', pre-flowering leaf removal, post-flowering leaf removal, aromatic compounds, thiols, LC-MS
Published in RUNG: 14.01.2016; Views: 8203; Downloads: 304
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