scholarly journals Determination of Glutathione in Austrian Wine Samples: The Effects of Freezing, the Choice of Yeast and Storage

2019 ◽  
Author(s):  
Danka Dragojlović ◽  
Christian Philipp ◽  
Karin Korntheuer ◽  
Christian Bader ◽  
Elsa Patzl-Fischerleitner ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Protective Effect ◽  
Alcoholic Fermentation ◽  
Freezing Process ◽  
Grape Variety ◽  
Nitrogen Gas ◽  
Grape Juices ◽  
Grape Varieties ◽  
And Storage

Glutathione (GSH, γ-L-Glutamyl-L-Cysteinyl Glycine) is a tripeptide of L-glutamate, L-cysteine and glycine. GSH in wine is derived from either grapes or yeast, during alcoholic fermentation. The GSH concentration in wine is very variable and depends on the environmental conditions as well as viticultural practices. During winemaking GSH has a significant role in oxidation prevention due to its unique redox and nucleophilic properties. Since GSH is very reactive it is highly important to prepare samples immediately and under inert conditions just prior to the determination of the GSH concentration. Therefore the aim of this research was to implement a method for the quantitative determination of GSH levels in grape juices (musts) made from different Austrian grape varieties and to investigate the influence of yeast on the GSH content in wine after aging. The results of this research have shown that monitoring with nitrogen gas, sulphur dioxide and freezing process at −25 ºC led to a good protective effect on the free glutathione amount in wine and grape samples. The GSH concentration in the samples was variable. Levels were ranging from non-detectable to up to 23.10 mg/l, and it showed that grape variety has no impact on GSH concentration in the must. Furthermore the results suggest that the choice of yeast has an impact on GSH content in wine even after 6 and 18 months of aging.

Fast quantitative determination of phenolic compounds in grape juice by UPLC-MS: method validation and characterization of juices produced with different grape varieties

2020 ◽  
Author(s):  
Natalia Alejandra Pisoni Canedo-Reis ◽  
Celito Crivellaro Guerra ◽  
Letícia Flores da Silva ◽  
Luísa Carolina Wetzstein ◽  
Carlos Henrique Junges ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Quantitative Determination ◽  
Method Validation ◽  
Grape Juice ◽  
Grape Varieties

Setting up of an Isotope Analyser for Quantitative Determination of Percentage Abundance of15N in Nitrogen Gas

1994 ◽  
Vol 27 (12) ◽  
pp. 2369-2376 ◽  
Author(s):  
M. Singh ◽  
R. Venkatasubramanian ◽  
T. K. Balasubramanian ◽  
V. V. Athalye
Keyword(s):  
Quantitative Determination ◽  
Nitrogen Gas ◽  
Percentage Abundance

scholarly journals Effect of grape variety (Vitis vinifera L.) and grape pomace fermentation conditions on some volatile compounds of the produced grape pomace distillate

OENO One ◽  
2004 ◽  
Vol 38 (4) ◽  
pp. 225 ◽  
Author(s):  
Maria Gerogiannaki-Christopoulou ◽  
Nikolaos V. Kyriakidis ◽  
Panagiotis E. Athanasopoulos
Keyword(s):  
Citric Acid ◽  
Vitis Vinifera ◽  
Volatile Compounds ◽  
Internal Standard ◽  
Grape Pomace ◽  
Grape Variety ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Grape Varieties

<p style="text-align: justify;">Agrape pomace distillate was produced from 4 Greek white grape varieties (<em>Vitis vinifera</em> L.). Pomace was fermented with and without addition of citric acid, acting as an antibacterial agent, during fermentation. Fermented grape pomace was distilled in a traditional copper distillation apparatus.. Five major volatile compounds, including methanol, were measured. Pentanol-3 was used as an internal standard. Flame ionization detector (FID) coupled to capillary gas chromatography was used for determination of five volatile distillate components. The addition of citric acid resulted in the reduction of methanol content by about 15%. All the other components studied did not affect in any appreciable degree.</p>

scholarly journals Antioxidant activity and storage regime of defatted grape seeds flour

Wine Studies ◽  
2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Adelina L. Bogoeva ◽  
Albena G. Durakova ◽  
Atanas I. Pavlov ◽  
Velichka B. Yanakieva ◽  
Radka Z. Vrancheva ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antioxidant Activity ◽  
Alcoholic Fermentation ◽  
Living Cells ◽  
Grape Seeds ◽  
Salmonella Spp ◽  
Plastic Bags ◽  
Grape Varieties ◽  
Locally Grown ◽  
And Storage

In the present paper, we examined the antioxidant activity of a defatted grape seeds flour of different grape varieties locally grown in Bulgaria. The seeds are retrieved after alcoholic fermentation and the antioxidant activity of the flour was assessed by using four different methods, namely DPPH, ABTS, FRAP and CUPRAC. The results are presented in mM TE/g extract. The values are 586,08 (±41,55); 945,41 (±90,97); 553,39 (±45,57) and 667,73 (±64,30), respectively. The results are also showed in mM TE/g flour. The values are 58,67 (±4,16); 94,64 (±9,11); 55,40 (±4,56) and 66,85 (±6,44), respectively. During three-month storage of the flour in plastic bags (temperature 25 ºC and relative humidity 75%), no living cells of pathogenic organisms (Escherichia coli, Staphylococcus aureus and Salmonella spp.) or apparent molding were detected. The flour particle size has not changed either.

scholarly journals The effect of bud density on the composition of colour in red wines

2001 ◽  
Vol 7 (3-4) ◽  
Author(s):  
Z. Barócsi ◽  
I. Balogh ◽  
M. Kállay ◽  
G. Lukácsy
Keyword(s):  
Red Wines ◽  
Grape Variety ◽  
Grape Varieties ◽  
Fruit Load

Authors investigated the effect of fruit load on the composition of colour substances and of reservatrol in red wines of some grape varieties grown in Hungary. The content of both, anthocyanin compounds and reservatrol showed practically the same responses to fruit load and the same profile in all the varieties studied. Determination of these compounds solely is not sufficient to identify the respective grape variety.

Quantitative determination of longitudinal and transverse cross-relaxation rates

1999 ◽  
Vol 96 (9/10) ◽  
pp. 1608-1615
Author(s):  
T. E. Malliavin ◽  
H. Desvaux ◽  
M. A. Delsuc
Keyword(s):  
Quantitative Determination ◽  
Cross Relaxation ◽  
Relaxation Rates

Quantitative Determination of Gallic acid and Cyanidin-3-O-Glucoside within Sumac Extracts by HPLC-MS/MS

Planta Medica ◽  
2011 ◽  
Vol 77 (12) ◽  
Author(s):  
M Koşar ◽  
F Göger ◽  
N Kırımer ◽  
KHC Başer
Keyword(s):  
Quantitative Determination ◽  
Gallic Acid
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