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32. Yeasts and wine colourDorota Korte, Olga Butinar-Čeh, Jelena Topić Božič, Branka Mozetič Vodopivec, 2019, pregledni znanstveni članek Najdeno v: osebi Ključne besede: yeast, Saccharomyces, non-Saccharomyces, wine colour, pyranoanthocyanins Objavljeno: 20.12.2019; Ogledov: 2150; Prenosov: 0
Polno besedilo (1,01 MB) |
33. Occurence of biogenic amine - producing lactic acid bacteria in Refošk grape and wineJelena Topić Božič, Jan Reščič, Martina Bergant Marušič, Klemen Lisjak, Branka Mozetič Vodopivec, Lorena Butinar, 2019, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Lactic acid bacteria (LAB) are naturally present in grapes, musts and wines. During malolactic fermentation, besides the beneficial conversion of L-malic to L-lactic acid, LAB can form also other compounds like biogenic amines (BAs). BAs are formed through decarboxylation of corresponding amino acids, through the action of enzymes. Consumption of food containing BAs can lead to food poisoning such as histamine poisoning. Histamine, the most studied BA, is known to cause headaches, oedema, vomiting.
In the last years, BAs associated pathways have been described as strain dependent and not as species dependent. Because of the high variability of microorganisms to decarboxylase amino acids, the detection of bacteria that have the possibility to transform precursor amino acid into BAs is very important in order to estimate the risk of BAs accumulation in wines. Since in previous years during project AGROTUR I we detected the higher BA content in some wines, we decided to focus on the presence of BA-producing LAB in Refošk grapes and wines. Therefore, during AGROTUR II project LAB collection of autochthonous lactic acid bacteria was set-up by isolating LAB from Refošk grapes and wines, originated from the grape growing cross-border region Karst (Slovenia). Over 600 isolates were obtained using MRS medium with added cycloheximide and 2% tomato juice. In parallel, also selective enrichment was performed using MRS medium described above with additionally added 5% ethanol. BA-producing LAB were primarily detected in microtiter-plate format using the decarboxylase screening medium with added amino acids (histidine, lysine, ornithine or tyrosine), which enable us to identify histamine-, cadaverine-, ornithine and tyrosine-producing LAB. Selected representatives from each BA-producing LAB groups were further on confirmed with chromatographic analysis (HPLC) and molecular methods (multiplex PCR method). BA-producing LAB were in majority represented by thyramin-producers, thereafter followed cadaverine-producers, with putrescine and histamine producers being the least presented. This screening of the BA-producing LAB is also incorporated in our on-going accurate selection of LAB starters for potential production of Refošk wines. Najdeno v: osebi Ključne besede: biogenic amines, lactic acid bacteria, refošk, grape, wine Objavljeno: 22.01.2020; Ogledov: 1940; Prenosov: 0
Polno besedilo (185,72 KB) |
34. The impact of Saccharomyces and non-Saccharomyces yeasts on wine colour: a laboratory study of vinylphenolic pyranoanthocyanin formation and anthocyanin cell wall adsorptionBranka Mozetič Vodopivec, Dorota Korte, Irena Vovk, Alen Albreht, Lorena Butinar, Jelena Topić, 2020, izvirni znanstveni članek Najdeno v: osebi Ključne besede: Non-Saccharomyces yeast, Hydroxycinnamate decarboxylase activity, Sequential fermentation, Vinylphenolic pyranoanthocyanins, Anthocyanin adsorption Objavljeno: 23.01.2020; Ogledov: 1820; Prenosov: 0
Polno besedilo (919,86 KB) |
35. Synthesis of pyranoanthocyanins from Pinot Noir grape skin extract using fermentation with high pyranoanthocyanin producing yeasts and model wine storage as potential approaches in the production of stable natural food colorantsDorota Korte, Irena Vovk, Alen Albreht, Lorena Butinar, Karin Kovačević Ganić, Natka Ćurko, Jelena Topić, Branka Mozetič Vodopivec, 2020, izvirni znanstveni članek Najdeno v: osebi Ključne besede: Pyranoanthocyanins, Anthocyanins, Food colorants, Yeasts, Fermentation Objavljeno: 03.04.2020; Ogledov: 1823; Prenosov: 0
Polno besedilo (1,03 MB) |
36. Implementation of high performance liquid chromatography coupled to thermal lens spectrometry (HPLC‑TLS) for quantification of pyranoanthocyanins during fermentation of Pinot Noir grapesLorena Butinar, Jelena Topič Božič, Natka Ćurko, Karin Kovačević Ganić, Branka Mozetič Vodopivec, Dorota Korte, Mladen Franko, 2020, izvirni znanstveni članek Opis: In this work high performance liquid chromatography coupled to thermal lens spectrometry (HPLC-TLS) was applied for monitoring of vinylphenolic pyranoanthocyanins formation during the fermentation of Pinot Noir wines. Vinylphenolic pyranoanthocyanins are wine pigments, present in low concentrations, but very important for wine colour stability.
Fermentation process was conducted with four different yeast strains, used as starters, either in sequential fermentation of non-Saccharomyces with S. cerevisiae yeast or as single fermentation with S. cerevisiae yeasts in order to test the applicability of developed method for monitoring of selected compounds in real wine fermentation experiments. The
developed HPLC-TLS method showed higher sensitivity compared to HPLC coupled to diode array detection (DAD) technique for particular wine colour compounds. Obtained limits of detection (LODs), were 6- and 22-times lower in comparison to HPLC–DAD in gradient and isocratic elution mode, respectively, whereas limits of quantification (LOQs)
5 and 18-times lower. Lower LODs enabled earlier observation of vinylphenolic pyranoanthocyanins formation during fermentation (already at day 7) in the case of HPLC-TLS method in gradient mode, while by using HPLC–DAD in gradient elution mode the formation of vinylphenolic pyranoanthocyanins was noticed only after 12 days of fermentation. Najdeno v: osebi Ključne besede: Thermal lens spectrometry (TLS), High performance liquid chromatography (HPLC), Pyranoanthocyanins, Wine, Yeasts Objavljeno: 18.06.2020; Ogledov: 1741; Prenosov: 0
Polno besedilo (1,94 MB) |
37. Determination of biogenic amine-forming potential of naturally occuring lactic acid bacteria (LAB) strains isolated from the grapes of Vitis vinifera cv. Refošk grape varietyDorota Korte, Branka Mozetič Vodopivec, Lorena Butinar, Martina Bergant Marušič, Jelena Topić, 2020, objavljeni povzetek znanstvenega prispevka na konferenci Opis: Biogenic amines are naturally occurring compounds that have been reported in variety of food, such as fish, meat, cheese, vegetables, and wines. When biogenic amines are formed by microorganisms such as lactic acid bacteria (LAB) they may have adverse effect on human health. The most common biogenic amines found in foodstuff are histamine, tyramine, putrescine and cadaverine. LAB are used as starters in the production of several foods and beverages. In wines they are used in malolactic fermentation, where the conversion of malic acid to lactic acid occurs. The aim of this work was to determine biogenic amine-forming capacity of indigenous LAB strains isolated from grapes which were PCR positive and screening medium positive for biogenic amines. Three methods for the confirmation of LAB biogenic amine-forming potential were developed and compared: HPLC-DAD and TLC methods both using derivatization agent dansyl chloride and enzymatic method using horseradish peroxidase (HRP) and diamine oxidase (DAO) enzymes. The applicability of methods was tested on the three known biogenic amine-producing LAB strains: 0006, 9809, 9906 (IOEB, France). The limit of detection (LOD) of the methods was <1 mg/L for HPLC-DAD, 5 mg/L for TLC and 25 mg/L for enzymatic method. Although the LODs between the proposed methods differed, all of the three methods confirmed BA-forming potential of the three strains. Furthermore, the proposed methods were applied for the analysis of three indigenous strains: MKBT-282 (BA+), MKBT-307 (BA-) and MKBT-325 (BA+). The positive or negative BA-forming potential was confirmed with all of the three proposed methods. Najdeno v: osebi Ključne besede: lactic acid bacteria, biogenic amines, histamine, grape Objavljeno: 10.07.2020; Ogledov: 1551; Prenosov: 0
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39. e-KletBranka Mozetič Vodopivec, Erika Jež, Lorena Butinar, Marko Lesica, Melita Sternad Lemut, Guillaume Antalick, 2020, drugo učno gradivo Najdeno v: osebi Ključne besede: interaktivno učno gradivo, pridelava vina, posamezne faze pridelave, sveže belo vino Objavljeno: 23.02.2021; Ogledov: 967; Prenosov: 0
Polno besedilo (5,68 MB) |
40. Marketinška raziskava o potrebah usposabljanj s področja vinogradništva, vinarstva, promocije in trženja vina na področju primorske vinorodne deželeYue Ma, Natallia Person, Katarina Marković, Tereza Valentinčič, Kristina Cotič, Vanesa Klinec, končno poročilo o rezultatih raziskav Najdeno v: osebi Ključne besede: projekti, marketinške raziskave, potrebe, izobraževanje, vinogradništvo, vinarstvo Objavljeno: 23.02.2021; Ogledov: 1077; Prenosov: 0
Polno besedilo (726,57 KB) |