Determination of Glutathione in Austrian Wine Samples: The Effects of Freezing, the Choice of Yeast 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

A Common Path to Innate Immunity to HIV-1 Induced by Toll-Like Receptor Ligands in Primary Human Macrophages

Toll-like receptors (TLR) represent the best characterized receptor family transducing innate immune responses, the first line of defense against microbial invaders. This study was designed to investigate whether responses through TLR inhibit HIV-1 replication in its primary target cells. Primary human macrophages and lymphocytes from several different donors and HIV-1 infection in tissue culture were used exclusively in this work. We report that ligands of three different TLR: LPS, R848, and double stranded RNA, induce a common antiviral response in macrophages as assayed by measurement of HIV-1 p24 protein, gag DNA, and entry into cells. HIV-1 infection is arrested after efficient entry but prior to reverse transcription. TLR-ligand activated cells secrete antiviral factors that induce a similar restriction. HIV-1 infection of lymphocytes is not affected by exposure to TLR ligands or to antiviral factors secreted by activated macrophages. TBK1, but neither NF-κB nor JAK-STAT activity, is required in macrophages to mount this antiviral response; the combination of p38 MAPK and JNK are partially required for induction of antiviral activity. Based on transcriptional induction and inhibition, the TLR-linked antiviral activity is different from APOBEC3 A or G, interferon-β, NAMPT, or p21Cip1. The cell-type specificity, site of action, and requirement for signaling intermediates suggest that the TLR-linked antiviral activity is novel

Influence of different yeasts on the amino acid pattern of rosé wine

In an experiment with Rosé wine, 27 different commercial yeasts were tested for their influence on the amino acid pattern of the wine. Amino acids are precursors for aromatic substances; therefore a large variation of the amino acid values in the wine was expected. Blaufränkisch grapes with 20° KMW were matured in the cellar with 27 different commercial yeasts. The fermentation was carried out in 34l vessels. The wines were measured for amino acids using an HP 1200 liquid chromatograph and HP-FLD1100 according to Umagat. The wines showed 13.5% alcohol and little residual sugar. The measurement results of the amino acids of the different wines showed large variations. For example, the amount of the amino acid alanine in wine varied from 17 to 138 mg. In particular, the wines of the yeast Pino Type showed the highest amounts of alanine in comparison to the other fermented wines

Influence of different yeasts on the amino acid pattern of rosé wine

In an experiment with Rosé wine, 27 different commercial yeasts were tested for their influence on the amino acid pattern of the wine. Amino acids are precursors for aromatic substances; therefore a large variation of the amino acid values in the wine was expected. Blaufränkisch grapes with 20° KMW were matured in the cellar with 27 different commercial yeasts. The fermentation was carried out in 34l vessels. The wines were measured for amino acids using an HP 1200 liquid chromatograph and HP-FLD1100 according to Umagat. The wines showed 13.5% alcohol and little residual sugar. The measurement results of the amino acids of the different wines showed large variations. For example, the amount of the amino acid alanine in wine varied from 17 to 138 mg. In particular, the wines of the yeast Pino Type showed the highest amounts of alanine in comparison to the other fermented wines

Influence of different commercial yeasts on the phenol pattern of rosé wine

In this experiment, 27 different commercial yeasts were tested for their influence on the phenols of a rosé wine. The phenols depend primarily on the vine variety, cultivation and cellar processing. This experiment sought to clarify how great the influence of the yeast on the phenols is. Blaufränkisch grapes with 20° KMW were matured in the cellar with 27 different commercial yeasts. The vinification was carried out in 34 l vessels. An HPLC Agilent Technology 1220 (RRLC) with a column of ZORBAX SB-C18 15 × 2.1 mm (1.8 μm) was used for the measurement. 5 μl of the sample were injected directly. The column oven temperature was 40 °C. The transient was 0.5% formic acid (pH = 2.3) and a gradient of methanol (3%, 4%, 14%, 30% and 70%). The detection took place at 280 and 320 nm. It was shown that the effect of yeast on phenols is low. There was a great influence on the chemical substance tyrosol. This is a phenol that can be formed by the yeast itself. The values varied between 5.4 mg and 13.2 mg/l. The already described influence of the duration of fermentation on tyrosol formation could not be confirmed

Influence of different commercial yeasts on the phenol pattern of rosé wine

In this experiment, 27 different commercial yeasts were tested for their influence on the phenols of a rosé wine. The phenols depend primarily on the vine variety, cultivation and cellar processing. This experiment sought to clarify how great the influence of the yeast on the phenols is. Blaufränkisch grapes with 20° KMW were matured in the cellar with 27 different commercial yeasts. The vinification was carried out in 34 l vessels. An HPLC Agilent Technology 1220 (RRLC) with a column of ZORBAX SB-C18 15 × 2.1 mm (1.8 μm) was used for the measurement. 5 μl of the sample were injected directly. The column oven temperature was 40 °C. The transient was 0.5% formic acid (pH = 2.3) and a gradient of methanol (3%, 4%, 14%, 30% and 70%). The detection took place at 280 and 320 nm. It was shown that the effect of yeast on phenols is low. There was a great influence on the chemical substance tyrosol. This is a phenol that can be formed by the yeast itself. The values varied between 5.4 mg and 13.2 mg/l. The already described influence of the duration of fermentation on tyrosol formation could not be confirmed

Hygienekontrolle von Betriebs- und Spülwasser in Kellereien mittels Kikkoman Lumitester PD-20 und ATP-Teststäbchen

In this experiment RLU (relative light units) values of water of the filling stations of six wineries were examined before and after cleaning. For measurements of the ATP amounts an instrument from Kikkoman was used. This technique is very well suited for cleaning inspection. It shows quickly if the surface of filling station or water is clean or dirty. In this experiment rinse water of six wineries has been tested with LuciPac Pen (cotton swab for surface inspection) and LuciPac Pen-Aqua (special pens for water analysis). For most of the samples, the ATP measurements were made immediately after sample collection, with the remaining samples, the RLU values were taken only in the laboratory. The average ATP values of tap waters are approximately 20 RLU in Austria. This value agrees well with the water value of the Education and Research Center of Viticulture and Pomology in Klosterneuburg. The RLU amount was around 15 RLU. In wineries where well water was used as process water, dangerous germs were isolated. These bacteria were identified by Vitek 2 compact as soil bacteria of the family Pseudomonaceae

Quantitative trait loci analysis of erinose (Eriophyes vitis Pgst.) on a genetic map Welschriesling x Sirius

Three biological races of Erinose (Eriophyes vitis Pgst. sin Colomerus vitis Pgst.) commonly attack vineyards every year. A genetic map Welschriesling x Sirius (Mandl et al. 2006) was used as the basis of QTL (quantitative trait loci) analysis for Erinose. The symptoms were evaluated in five consecutive years in 92 individuals from this segregating population and other OIV traits related to the density of hairs in different tissues were also scored. QTL analysis was performed on all data using Plabqtl version 1.1. A major QTL for Erinose sensitivity was identified and reproducible every year on linkage group 9d close to the SSR marker VMC5c1. Two additional smaller QTLs could also be identified in linkage groups 5 and 17. The fact that some OIV traits related to the density of hairs were linked to the same group of the genetic map, is also discussed.Peer Reviewe