Oxygen transfer rate measurements of closure systems after 12 years of aging. Impact on the aroma compounds of Sauvignon Blanc wines

Abstract

Three Sauvignon Blanc wines sealed with seven closure types (natural corks, three microagglomerate corks, synthetics and two screw caps) were analyzed after 12 years of aging. OTR (oxygen transfer rate) of old stoppers (12 years) were determined by a strandardized protocol using coulometry. The other analytical markers were volatile thiols and Strecker aldehydes determined by gas chromatography coupled with tandem mass spectrometry. Sulfites, dissolved CO₂ measurements and sensory analysis of the wines were also carried out. We showed that the OTR value changed after 12 years and the variability depends on the type of stoppers and ranged from 0.05 to 89.11 mg/year. The molecular markers analysed made it possible to illustrate the sensory perception of the evolution of this wine. Molecular characterisation revealed that an average OTR_12years of 0.27 mg/year allows preservation of thiols while delaying the formation of Strecker aldehydes whereas beyond 0.82 mg/year in average, wines develop first signs of oxidation.