Fermentation, wine yeast

The aim of this study, performed on Sauvignon blanc clones SB11 and SB316, grafted the same rootstock 101-14 Mgt (Vitis riparia × V. ruperstris) grown at two adjacent vineyards, was two-fold: (1) to study wine chemical sensory composition both within an unaltered canopy; (2) determine effect defoliation (e.g. bunch microclimate) composition.Orthogonal projection latent structures discriminate analysis (OPLS-DA) applied concentration profiles volatile compounds derived from gas...

The aroma profile is an important marker for wine quality. Various classes of compounds are responsible the wine, and one such class terpenoids. In context this work, a validated gas chromatography-mass spectrometry (GC-MS) method quantitation terpenoids in red white using headspace solid-phase microextraction (HS-SPME) extraction (SPE) was established. Calibrations were performed respective base both sample preparation methods. linearity, precision accuracy evaluated matrices excellent...

Background and Aims The thiol compounds, 3-mercaptohexan-1-ol (3MH) 3-mercaptohexyl acetate (3MHA), are important, pleasant volatile thiols conferring fruity notes in wines. analytical determination of these wine remains problematic due to their trace concentration instability. main aim this study was develop a liquid/liquid extraction ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the 3MH 3MHA Sauvignon Blanc Methods Results A novel sample...

Wine varietal thiols are important contributors to wine aroma. The chemical nature of makes them difficult measure due low concentrations, high sensitivity oxidation, and ionization. Methods for the measurement usually consist multiple steps sample preparation followed by instrumental measurement. Studies have collected large datasets in white but not red wine, lack availability suitable methods. In this study, first time, convergence chromatography was used at ultratrace levels with...

The aim of the study was to propose a methodology for elucidation sensory and chemical wine quality drivers. winners 2018 Top 10 Chenin Blanc Pinotage challenges additional lower scoring wines each cultivar were evaluated. two sets underwent profiling by Check-All-That-Apply (CATA) 20-point rating industry experts in non-competition conditions fingerprinting Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS). Data submitted Correspondence Analysis (CA) Principal Component...

The increased incidence of vegetation fires near vineyards in the Western Cape, South Africa has led to growing concern over appearance smoke taint affected grapes.This study focused on effect exposure volatile phenol (VP) composition wines made from grapes two vintages (2012 and 2013).Cabernet Sauvignon were exposed, 10 days post-véraison, a single, hour-long treatment with derived burning mixture (including fynbos) under controlled conditions enclosures.Enclosures sealed for 24 h after...

The odor detection threshold (ODT) of a compound is the lowest concentration at which individuals can reliably perceive difference between sample and its corresponding control, with 50% performance above chance. Wine complex matrix, ODTs used in studies on wine be based inappropriate matrices informal sensory methodologies. Formal confirming are relatively scarce literature, expensive to carry out. In this study, sensitivity panelists previously published for five compounds: Guaiacol,...

Lipids are essential components of all living cells. In an oenological context, the supply unsaturated lipids in grape juice allows yeasts to grow and ferment, despite very low levels oxygen. The current study proposes a systematic optimization procedure for analysis fatty acids sterols relevant fermentation process, including both extracellular intracellular (i.e., yeast cells) lipids. Even though it was extensive, sample preparation yielded reproducible results compounds interest....

In oenology, statistical analyses are used for descriptive purposes, mostly with separate sensory and chemistry data sets. Cases that combine them supervised, usually seeking to optimize discrimination, classification, or prediction power. Unsupervised methods as preliminary steps achieving success in supervised models. However, there is potential unsupervised different sets into comprehensive, information-rich This study detailed stepwise strategies creating fusion models using techniques...

Abstract A procedure is described for the slurry packing of 50‐μm ID fused silica capillaries with 3‐μm octadecyl (ODS) particles capillary electrochromatography (CEC) and its hyphenation electrospray ionisation mass spectrometry (ESI/MS). homogeneous packed bed obtained by using a slow process in an upward direction balanced density solvent MeOH as solvent. Special attention was paid to in‐ outlet frit preparation order avoid gas bubble formation which renders CEC‐ESI/MS problematic. Frits...

The qualitative perceptual interactions of single and binary mixtures four compounds: guaiacol ('burnt/smoky'), o-cresol ('phenolic/tar'), 4-ethylphenol (4-EP, 'leather/barnyard'), 2-isobutyl-3-methoxypyrazine (IBMP, 'green pepper/herbaceous'), were studied in a partially de-aromatised red wine matrix. Using Descriptive Analysis, each compound was characterised individually by trained panel eleven judges at peri- sub-threshold levels. Binary all compounds subsequently the same matrix using...