Impact of must hyperoxygenation on the aromatic profile of Fernão Pires white wine

Abstract

This work intended to evaluate the impact of must hyperoxygenation on the aromatic profile of Fernão Pires variety. After grapes pressing, the must was hyperoxygenated, with a Vivelys micro-oxygenator, at two different levels of oxygen: 7 mg/L and 14 mg/L, for 6 hours. The must control was only sulphited. The fermentations took place at a controlled temperature of 15ºC. After the liquid-liquid extraction with dichloromethane from the wine samples, the obtained extracts were analyzed by high resolution gas-liquid chromatography coupled with mass spectrometry (CG-MS). The wines obtained were also subjected to sensory analysis. There was an increase in the content of ethyl acetate, isoamyl acetate, ethyl 3-hydroxybutyrate, ethyl decanoate, ethyl monosuccinate and ethyl hexadecanoate, and of most alcohols with the increase in the oxygen dose applied, especially isoamyl alcohols and 2-phenylethanol. Hyperoxygenation negatively affected terpenes alcohols (linalool and α-terpineol) and benzene compounds such as benzyl alcohol and 4-vinylguaiacol, contrary to what was observed for most fatty acids. The sensory analysis did not reveal significant differences between the wine modalities for olfactory attributes and taste attributes. There were only significant differences for the overall quality. The tasters considered that the wine subjected to the highest dose of oxygen and the control wine had better overall quality.