Yeast diversity during the spontaneous fermentation of wine in a winery and in a laboratory using sterilized equipment.

A recent trend in some wineries is the return to using spontaneous fermentation, but it is not clear whether winery flora or vineyard microorganisms drive fermentation. We compared fungal communities during the spontaneous fermentation of wine produced in a winery and in a laboratory with sterilized equipment using three grape cultivars (Chardonnay, Merlot, and Muscat Bailey A) obtained from the same harvest. High-throughput sequencing analysis based on the ITS1 region showed that Saccharomyces cerevisiae was the dominant species in winery batches at the end of fermentation, but it was not always dominant in laboratory batches.

Yeast diversity during the spontaneous fermentation of wine with only the microbiota on grapes cultivated in Japan.

Making wine via spontaneous fermentation without sulfur dioxide and commercial yeast (spontaneous winemaking) is increasing in recent year, but there is scant research regarding microbial communities present in Japan during spontaneous winemaking using culture-independent molecular methods. We analyzed fungal communities and populations during laboratory-scale spontaneous winemaking using sterilized labware to avoid winery-resident microbes. In the spontaneous fermentation of four grape varieties (Pinot Noir, Riesling, Koshu, and Koshusanjaku) grown in the same Japanese vineyard, our analysis of yeast and other fungal species by next-generation sequencing based on the ITS1 region demonstrated that Saccharomyces cerevisiae was eventually dominant in seven of 12 fermentation batches (three replications for each grape variety), whereas non-Saccharomyces species (e.

Genetic architecture of berry aroma compounds in a QTL (quantitative trait loci) mapping population of interspecific hybrid grapes (Vitis labruscana × Vitis vinifera).

Background: Although grapes accumulate diverse groups of volatile compounds, their genetic regulation in different cultivars remains unelucidated. Therefore, this study investigated the volatile composition in the berries of an interspecific hybrid population from a Vitis labruscana 'Campbell Early' (CE) × Vitis vinifera 'Muscat of Alexandria' (MA) cross to understand the relationship among volatile compounds and their genetic regulation. Then, a quantitative trait locus (QTL) analysis of its volatile compounds was conducted.

Chemometric approaches for determining the geographical origin of Japanese Chardonnay wines using oxygen stable isotope and multi-element analyses.

Determining the geographical origin of wines is a major challenge in wine authentication, but little information is available regarding non-parametric statistical approaches for wines. In this study, we collected 33 domestic Chardonnay wines vinified on a small scale from grapes cultivated in Japan, and 42 Chardonnay wines imported from 8 countries, for oxygen stable isotope and multi-element analyses. Non-metric multidimensional scaling (NMDS), kernel principal component analysis (KPCA) and principal component analysis (PCA) were applied to the oxygen stable isotopic compositions (δO) and the concentrations of 18 elements in the wines to compare the extractions by parametric and non-parametric methods.

Prediction method for determining the carbon stable isotopic composition of berry sugars in the original must of Chardonnay wines.

The carbon stable isotopic composition, as indicated by the δC value, of wine ethanol is inherited from berry sugars, but little is known about the variation in sugar δC values of Japanese grapes relative to overseas grapes. This study found a large variation in sugar δC values of Chardonnay grapes grown in Japan (-27.2 ± 0.