Experiments with oenological methods to increase the spicy aroma in Austrian Grüner Veltliner wines

Grüner Veltliner is Austria's most important grape variety, accounting for 32.5% of the vineyard area (a total of around 14,500 ha). There is a noticeable trend with this variety away from fresh, fruity wines towards more spicy, single-vineyard wines. This is especially true for export-oriented producers. The aim of this scientific study is to test oenological methods for increasing the leading substance of the spicy aroma, the sesquiterpene rotundone and to sensory evaluate the wines. The methods skin contact, full and partial fermentation on the skins, addition of whole grapes and or leaves were tested in two independent experimental designs. The wines were analysed using a SPE-SPME-GC-TQMS method. The "retro-tratitional methods" of winemaking mentioned in the article can enhance the spiciness of the wines to a certain degree. Especially the addition of whole grapes as well as partial maceration gave the best results here. The increase in spiciness was observed both sensorially and analytically, as evidenced by higher rotundone contents. However, in summary, it must be stated that the results indicate that an exclusive analysis of rotundone, without the inclusion of phenols and other volatile substances, cannot contribute to a full understanding of the matter, which is based on the interaction of many components. Further analysis both sensory and analytical involving many volatile compounds and phenols are therefore absolutely necessary

Meeting Minutes for October 13, 2016

Raw DICOM image files of CT-scanned termite mound Tp

Left Shifting of Language Related Activity Induced by Bihemispheric tDCS in Postacute Aphasia Following Stroke

Both anodal transcranial direct current stimulation (tDCS) of the left IFG and cathodal stimulation of the right IFG were shown to improve rehabilitation of stroke patients with Broca’s aphasia. The study aimed at assessing the impact of a bihemispheric IFG stimulation compared to sham on postacute non-fluent aphasia. Twelve patients with non-fluent aphasia were included at least 4 weeks following cerebral stroke. Ten daily sessions of 2 mA bihemispheric verum or sham tDCS (anode on left IFG and cathode on right IFG) were performed concomitantly with individual language therapy in a double-blinded randomized controlled study with parallel group design. Language functions [i.e., communication (ANELT), picture naming and the Aachen aphasia test (AAT)] were assessed up to 1 month following tDCS. The picture naming task significantly improved (increased number of nouns) at the end of the tDCS procedure in the verum but not sham group. Improvements in the picture naming task and the communication task of the AAT at 4 weeks after tDCS procedure were only seen in the verum group. In patients with postacute cerebral stroke, repeated sessions of tDCS applied on both IFG concomitantly with language therapy were able to induce immediate effects on picture naming presumably due to an early left shift of language-associated function that maintained for 4 weeks. Effects on clinically relevant communicative abilities are likely

Determination and elimination of rotten grape aroma by filter layers with selective adsorbers

The most important mould associated substances like geosmine, 2-methylisoborneol, 1-octen-3-ol in wines of different grape varieties from Austria and also from other foreign countries were analysed by a HS-SPME GC-MS method. These substances were also determined in healthy and rotten grapes. All together, 391 wine-samples and 69 grape samples were examined. The study of rotten and healthy grapes found out a level of geosmin up to 20 ng/L, 1-octene-3-ol concentration up to 700 μg/L and 2-heptanol level up to 9 μg/L. The geosmin concentration of the 391 analyzed wines extended from 1-44 ng/L. The detected level of 1-octene-3-ol ranged from 1 μg/L to 23 μg/L. The determined concentration of 2-heptanol ranged from 1 μg/L up to 38 μg/L. The test with the filter layer Fibrafix TX-R was performed with nine layers á 20 × 20 cm (3.6 m2) and a quantity of 625 liters wine. The filtering achieved a significant reduction of the start concentration of 60 ng/L geosmin down to only 6 ng/L (average value of 600l)

On-farm trial on the effectiveness of the nitrification inhibitor DMPP indicates no benefits under commercial Australian farming practices

The trend of increasing nitrogen (N) fertilisation in commercial agriculture demands mitigation of negative impacts on the environment, such as emissions of the potent greenhouse gas nitrous oxide (N2O). Laboratory and controlled field experiments have demonstrated that the nitrification inhibitor 3,4-Dimethylpyrazole phosphate (DMPP) has the potential to effectively mitigate N2O emissions from dairy pasture and crop farming, and may increase yields. Yet, this has not been investigated in on-farm research trials under commercial production conditions. During the winter growing seasons 2014–2016 we performed an on-farm trial on five commercial broad-acre cropping and five dairy farms in North-East Victoria, Australia, to compare the performance of DMPP + urea (treatment) against conventional urea (control) fertiliser in mitigating N2O emissions and increasing crop and pasture yields. Application rate was fixed at the regional industry standard of 46 kg N ha‐1, yet timing, number of applications and all other management decisions were left to the judgement of the participating farmers. Emissions of N2O were highly variable over time and between farms. We recorded emission spikes of up to 250 g N2O-N h

Breeding of fungal resistant varieties derived from Grüner Veltliner by chromosomal selection

Traditional cultivar Grüner Veltliner is the most appreciated vine in Austrian viticulture. Due to organic growing the demand for mildew resistance within the same wine profile has increased. Cross breeding can provide such new genotypes which combine traits from different sources by parenthood. Linkage of traits with chromosomes or markers allows to predict some aspects of the phenotype. Equipped with chromosomal assisted selection the development of new varieties could be much easier and faster. On the base of two segregating populations derived from crosses of Grüner Veltliner with Malverina and Seyval blanc we could define correlation of chromosomes with some traits. Mainly ampelographic descriptors and resistance against mildew could be aligned. As a quality parameter of the wine Rotundone analyses were performed and could be attributed to chromosome 5 and 9. Selection supported by the composition of the parental chromosomes enables breeding with some arguments of design. The limits for free choice were the availability of sufficient different genotypes with a broad spectrum of chromosomal combinations. Recently released descendent cultivar Donauveltliner was selected due to the high rate of Traminer alleles

Breeding of fungal resistant varieties derived from Grüner Veltliner by chromosomal selection

Traditional cultivar Grüner Veltliner is the most appreciated vine in Austrian viticulture. Due to organic growing the demand for mildew resistance within the same wine profile has increased. Cross breeding can provide such new genotypes which combine traits from different sources by parenthood. Linkage of traits with chromosomes or markers allows to predict some aspects of the phenotype. Equipped with chromosomal assisted selection the development of new varieties could be much easier and faster. On the base of two segregating populations derived from crosses of Grüner Veltliner with Malverina and Seyval blanc we could define correlation of chromosomes with some traits. Mainly ampelographic descriptors and resistance against mildew could be aligned. As a quality parameter of the wine Rotundone analyses were performed and could be attributed to chromosome 5 and 9. Selection supported by the composition of the parental chromosomes enables breeding with some arguments of design. The limits for free choice were the availability of sufficient different genotypes with a broad spectrum of chromosomal combinations. Recently released descendent cultivar Donauveltliner was selected due to the high rate of Traminer alleles

Experiments with oenological methods to increase the spicy aroma in Austrian Grüner Veltliner wines

Grüner Veltliner is Austria's most important grape variety, accounting for 32.5% of the vineyard area (a total of around 14,500 ha). There is a noticeable trend with this variety away from fresh, fruity wines towards more spicy, single-vineyard wines. This is especially true for export-oriented producers. The aim of this scientific study is to test oenological methods for increasing the leading substance of the spicy aroma, the sesquiterpene rotundone and to sensory evaluate the wines. The methods skin contact, full and partial fermentation on the skins, addition of whole grapes and or leaves were tested in two independent experimental designs. The wines were analysed using a SPE-SPME-GC-TQMS method. The "retro-tratitional methods" of winemaking mentioned in the article can enhance the spiciness of the wines to a certain degree. Especially the addition of whole grapes as well as partial maceration gave the best results here. The increase in spiciness was observed both sensorially and analytically, as evidenced by higher rotundone contents. However, in summary, it must be stated that the results indicate that an exclusive analysis of rotundone, without the inclusion of phenols and other volatile substances, cannot contribute to a full understanding of the matter, which is based on the interaction of many components. Further analysis both sensory and analytical involving many volatile compounds and phenols are therefore absolutely necessary

Reduction in Off-Flavors in Wine Using Special Filter Layers with Integrated Zeolites and the Effect on the Volatile Profile of Austrian Wines

In the course of the present study, filter layers with embedded zeolites (patented layer of the company Filtrox (Zwingen, Switzerland) with the brand name Fibrafix® TX) were tested for the elimination of the wine defects, cork taint (2,4,6-trichloroanisole), mouldy aroma (geosmin), and strong “animal” phenolic aromas (4-ethylphenol, 4-ethylguaiacol, 4-ethylcatechol). The test design allowed a comparison with conventional filter layers (sterile filter layers) in a small-scale trial (25 L) as well as in a large-scale trial (125 L). By means of gas chromatography-mass spectroscopy, not only the impact compounds of the wine faults were analysed, but also the loss of volatile substances such as 15 free monoterpenes, 34 ester compounds, and 24 wood flavours. Sensory analyses were carried out by means of expert panels. The Fibrafix® TX layers were satisfactory with regard to the reduction in 2,4,6-trichloroanisole (the lead substance of cork flavour; reduction > 90%) and geosmin (the lead substance of mould flavour; reduction > 75%), but not with regard to the reduction in 4-ethylphenol, 4-ethylguaicol, and 4-ethylcatechol. However, the reduction in these off-flavours was generally not specific enough to prevent a loss of volatile compounds, especially various ester compounds and free monoterpenes. The wines obtained after filtration (in case of contamination with geosmin or TCA) were sensory faultless, but for some of the tasters, the overall quality of these wines did not correspond to the quality wine clasification

Reduction in Off-Flavors in Wine Using Special Filter Layers with Integrated Zeolites and the Effect on the Volatile Profile of Austrian Wines

In the course of the present study, filter layers with embedded zeolites (patented layer of the company Filtrox (Zwingen, Switzerland) with the brand name Fibrafix® TX) were tested for the elimination of the wine defects, cork taint (2,4,6-trichloroanisole), mouldy aroma (geosmin), and strong “animal” phenolic aromas (4-ethylphenol, 4-ethylguaiacol, 4-ethylcatechol). The test design allowed a comparison with conventional filter layers (sterile filter layers) in a small-scale trial (25 L) as well as in a large-scale trial (125 L). By means of gas chromatography-mass spectroscopy, not only the impact compounds of the wine faults were analysed, but also the loss of volatile substances such as 15 free monoterpenes, 34 ester compounds, and 24 wood flavours. Sensory analyses were carried out by means of expert panels. The Fibrafix® TX layers were satisfactory with regard to the reduction in 2,4,6-trichloroanisole (the lead substance of cork flavour; reduction > 90%) and geosmin (the lead substance of mould flavour; reduction > 75%), but not with regard to the reduction in 4-ethylphenol, 4-ethylguaicol, and 4-ethylcatechol. However, the reduction in these off-flavours was generally not specific enough to prevent a loss of volatile compounds, especially various ester compounds and free monoterpenes. The wines obtained after filtration (in case of contamination with geosmin or TCA) were sensory faultless, but for some of the tasters, the overall quality of these wines did not correspond to the quality wine clasification