41. Univerza v Novi Gorici, Spremljanje, ugotavljanje in zagotavljanje kakovosti, Poročilo za študijsko leto 2013/2014Iztok Arčon, Martina Bergant Marušič, Aleš Bogovič, Lorena Butinar, Gvido Bratina, IMRE CIKAJLO, Saša Dobričić, Elsa Fabbretti, Mladen Franko, Renata Kop, Urška Lavrenčič Štangar, Martin Knez, Katja Mihurko, Jana Laganis, Branka Mozetič Vodopivec, Egon Pavlica, Ingrid Petrič, Samo Stanič, Tea Stibilj Nemec, Arthur Stepanov, Boštjan Potokar, Veronika Piccinini, Peter Purg, Aljaž Rener, Nives Štefančič, Ana Toroš, Tanja Urbančič, Vanesa Valentinčič, Aleš Vaupotič, Sabina Zelinšček, 2014, treatise, preliminary study, study Keywords: zagotavljanje kakovosti, visoko šolstvo, univerza
Published in RUNG: 05.02.2018; Views: 5241; Downloads: 0
This document has many files! More... |
42. |
43. BIOTSKA RAZNOVRSTNOST KVASOVK POVEZANIH S PROIZVODNJO JABOLČNEGA VINAEivind 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: 6696; Downloads: 0
This document has many files! More... |
44. Biodiversity of cider yeasts and their cider-making potentialEivind 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: 7646; Downloads: 0
This document has many files! More... |
45. |
46. 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: 5704; Downloads: 0
This document has many files! More... |
47. |
48. 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: 6166; Downloads: 0
This document has many files! More... |
49. CHARACTERIZATION OF SLOVENIAN APPLE JUICE WITH RESPECT TO ITS GEOGRAPHICAL ORIGIN AND AGRICULTURAL PRODUCTION PRACTICEKarmen 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: 9169; Downloads: 910
 Full text (3,97 MB) |
50. 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: 7104; Downloads: 0
This document has many files! More... |
