Evaluation of antioxidant supplementation in must on the development and potential reduction of different compounds involved in atypical ageing of wine using HPLC-HRMS

Abstract

Atypical aging of white wines (ATA) is an off-flavour characterised by rapid loss of fruity aromas and the development of unpleasant odours.This study aims to evaluate the effectiveness of different oenological adjuvants (4-ethylcatechol, 4-methylcatechol, gentisic acid, hydroxytyrosol, ascorbic acid, glutathione, ellagic acid, gallic acid, galla tannin, ellagic tannin, quebracho, grape tannins) added to musts before fermentation for preventing the possible development of ATA. High resolution mass spectrometry made it possible to quantify and qualify free and conjugated IAA in wine at the end of the fermentation and subsequently 2-aminoacetophenone (AAP) was quantified after the force ageing period (6 days at 40 °C). Ascorbic acid was confirmed as the most appropriate antioxidant adjuvant which can be used for ATA defect prevention. With an almost comparable effect, gallotannin addition prevented AAP production to exceed 1 μg/L. A predicted model (ANCOVA) indicated that over 80% of the variability of potential AAP formation in wines was explained by the amount of precursors, grape variety and antioxidant treatment. Moreover, a suspect screening approach made it possible to study the kinetic formation and the consumption of the reaction metabolites formed during the oxidative degradation of IAA leading to AAP.