Chemical and Sensory Study on the Evolution of Aromatic and Nonaromatic Compounds during the Progressive Oxidative Storage of a Sauvignon blanc Wine.

The effect of repetitive controlled oxidation on the chemical and sensory composition of a fresh and fruity style Sauvignon blanc wine was investigated. Chemical analyses were conducted together with extensive sensory profiling. A decrease in volatile thiols responsible for the fruity nuances and an increase in oxidation-related compounds, such as acetaldehyde, during the course of the oxidation was observed. The wine evolved from a fresh and fruity one to one with slight oxidation and then developed extreme oxidative characteristics. The control samples (no oxygen added) developed a "cooked" character that could indicate the formation of "reductive" compounds in these wines. Conversely, the wines that received a single dose of oxygen did not develop this flavor and were perceived to be fresher and fruitier than the control samples. The color of the wine evolved before the disappearance of the pleasant aroma.

Enantiodifferentiation of 1,2-propanediol in various wines as phenylboronate ester with multidimensional gas chromatography-mass spectrometry.

Native concentrations and enantiomeric distribution of 1,2-propanediol in various wines were studied in order to evaluate its merits as a potential marker for aroma adulteration in wine. Heart-cut multidimensional gas chromatography coupled to mass spectrometry was applied to analyze 1,2-propanediol after salting-out of the polar phase, derivatization with phenyl boronic acid, and extraction with cyclohexane. The enantiomeric separation of the derivative was achieved with heptakis-(6-O-tert. butyl dimethylsilyl-2,3-di-O-acetyl)-ß-cyclodextrin as the chiral selector. In all authentic wines studied, 1,2-propanediol showed a high enantiomeric ratio in favor of the (R)-enantiomer, proving its potential as a marker for the adulteration with flavor extracts based on industrial 1,2-propandiol as solvent. Usually, concentrations varied between 15 and 100 mg/L. Higher values (up to 170 mg/L) were found in wines made with high amounts of dry berries. However, despite the higher concentrations of 1,2-propanediol in such wines, no apparent influence on the enantiomeric distribution could be detected. Graphical Abstract Detection of fraudulent aromatization of wines by enantiodifferentiation of 1,2-propanediol as its phenylboronate ester.