Alternative Perspective on Rapid Wine Oxidation through Changes in Gas-Phase Volatile Concentrations, Highlighted by Matrix Component Effects.

A new perspective is presented to investigate the sensorially relevant gas-phase concentrations of volatile compounds in wine. This is achieved by measuring the partition coefficients and matrix-phase concentrations of volatiles using static headspace-gas chromatography-ion mobility spectrometry. Physicochemical properties that can contribute to the partition behaviors of 10 volatile esters, such as hydrophobicity and matrix temperature, are also discussed.

Validation Study on the Simultaneous Quantitation of Multiple Wine Aroma Compounds with Static Headspace-Gas Chromatography-Ion Mobility Spectrometry.

A new quantitative method based on static headspace-gas chromatography-ion mobility spectrometry (SHS-GC-IMS) is proposed, which enables the simultaneous quantitation of multiple aroma compounds in wine. The method was first evaluated for its stability and the necessity of using internal standards as a quality control measure. The two major hurdles in applying GC-IMS in quantitation studies, namely, nonlinearity and multiple ion species, were also investigated using the Boltzmann function and generalized additive model (GAM) as potential solutions.

Volatile-Based Prediction of Sauvignon Blanc Quality Gradings with Static Headspace-Gas Chromatography-Ion Mobility Spectrometry (SHS-GC-IMS) and Interpretable Machine Learning Techniques.

The analytical scope of static headspace-gas chromatography-ion mobility spectrometry (SHS-GC-IMS) was applied to wine aroma analysis for the first time. The method parameters were first fine-tuned to achieve optimal analytical results, before the method stability was demonstrated, in terms of repeatability and reproducibility. Succinct qualitative identification of compounds was also realized, with the identification of several volatiles that have seldom been described previously in Sauvignon Blanc wine, such as methyl acetate, ethyl formate, and amyl acetate.

New precursor of 3-mercaptohexan-1-ol in grape juice: thiol-forming potential and kinetics during early stages of must fermentation.

Two volatile thiols, 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA), are key aroma impact compounds in many young white wines, especially of the variety Sauvignon blanc (SB). Although great effort has been invested to identify their precursors in recent years, the origin of the majority of 3MH and 3MHA generated during wine fermentation still cannot be explained. Here we demonstrate that supplying an external source of hydrogen sulfide to grape juice hugely increases its thiol-forming potential.

Evaluation of key odorants in sauvignon blanc wines using three different methodologies.

In this study three different approaches were employed to identify key odorants in Sauvignon blanc wines. First, the concentrations of the odorants were compared to their respective aroma detection thresholds. The resulting odor activity values (OAV) were transformed into a normalized and weighted measure that allows the aroma profiles of different wines to be compared and the contribution of a single aroma in a complex mixture to be evaluated.