Repository of University of Nova Gorica

Search the repository
A+ | A- | Help | SLO | ENG

Query: search in
search in
search in
search in
* old and bolonia study programme

Options:
  Reset


1 - 7 / 7
First pagePrevious page1Next pageLast page
1.
Polyphenol, antioxidant and antimicrobial potential of six different white and red wine grape processing leftovers
Peter Raspor, Sonja Smole Možina, Katja Jug, Melita Sternad Lemut, Branka Mozetič Vodopivec, Anja Klančnik, Kajetan Trošt, 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.
Found in: ključnih besedah
Keywords: grape skins and seeds, extraction solvents, phenolic profile, antioxidant activity, antimicrobial activity, anti-adhesion activity to stainless steel
Published: 08.08.2016; Views: 2412; Downloads: 0
.pdf Fulltext (2,02 MB)

2.
Study of grapevine early leaf removal sustainability potential by means of targeted metabolomic approach
Melita Sternad Lemut, Paolo Sivilotti, Lorena Butinar, Ajda Lemut, Urška Vrhovšek, 2017, published scientific conference contribution abstract

Found in: ključnih besedah
Summary of found: ...Pinot gris, early leaf removal, sustainable viticulture, grape compactness, targeted metabolomics, phenolic compounds...
Keywords: Pinot gris, early leaf removal, sustainable viticulture, grape compactness, targeted metabolomics, phenolic compounds
Published: 21.09.2017; Views: 2274; Downloads: 0
.pdf Fulltext (102,93 KB)

3.
4.
From the vineyard to the glass: How to assess red grape aromatic maturity with simple physiological indicators
Guillaume Antalick, Katja Šuklje, unpublished conference contribution

Found in: ključnih besedah
Keywords: Wine aroma, wine style, grape maturity, sequential harvest, berry sugar loading, fresh mass
Published: 19.09.2018; Views: 864; Downloads: 8
.pdf Fulltext (4,65 MB)
This document has many files! More...

5.
Controlling grape aromatic maturity in the context of global warming
Guillaume Antalick, Katja Suklje, unpublished invited conference lecture

Found in: ključnih besedah
Keywords: Wine style, grape maturity, berry shrivelling, berry sugar loading, fresh mass, sequential harvest
Published: 19.09.2018; Views: 800; Downloads: 0
.pdf Fulltext (34,61 KB)

6.
Occurence of biogenic amine - producing lactic acid bacteria in Refošk grape and wine
Jelena Topić Božič, Jan Reščič, Martina Bergant Marušič, Klemen Lisjak, Branka Mozetič Vodopivec, Lorena Butinar, 2019, published scientific conference contribution abstract

Abstract: 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.
Found in: ključnih besedah
Keywords: biogenic amines, lactic acid bacteria, refošk, grape, wine
Published: 22.01.2020; Views: 589; Downloads: 0
.pdf Fulltext (185,72 KB)

7.
Determination of biogenic amine-forming potential of naturally occuring lactic acid bacteria (LAB) strains isolated from the grapes of Vitis vinifera cv. Refošk grape variety
Dorota Korte, Branka Mozetič Vodopivec, Lorena Butinar, Martina Bergant Marušič, Jelena Topić, 2020, published scientific conference contribution abstract

Abstract: 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.
Found in: ključnih besedah
Keywords: lactic acid bacteria, biogenic amines, histamine, grape
Published: 10.07.2020; Views: 312; Downloads: 0
.pdf Fulltext (225,99 KB)

Search done in 0 sec.
Back to top