Influence of ascorbic acid, sulfur dioxide and glutathione on oxidation product formation in wine-like systems

Abstract

Abstract. The impact of the addition of ascorbic acid, sulfur dioxide and glutathione on oxidation product formation under accelerated oxidative conditions was evaluated in model wines. The effects of these antioxidants have been compared in aqueous ethanol solutions containing (+)-catechin and metal ions at pH 3.2 by monitoring O2 consumption, color evolution by CIELab, as well as (+)-catechin and glutathione decrease by LC-DAD/FD. The analysis of oxidation products formation was focused on the determination of yellowish colored xanthylium compounds by LC-ESI-ToFMS and acetaldehyde by HS-GC-FID. The results could show, that under some conditions glutathione could not inhibit carboxymethine-briged (+)-catechine dimer formation and subsequent xanthylium cation pigment generation, compared to ascorbic acid or sulfur dioxide addition providing a good protection against oxidative color changes. In systems containing 0.08 to 0.32 mmol/L glutathion without any further addition of SO 2 or ascorbic acid, increasing acetaldehyde concentrations could be observed. These results demonstrate clearly the need for further research to highlight the reactions of glutathione.

Detection with flash gas chromatography electronic nose of the general influences of glutathione, ascorbic acid, tannin and carbon dioxide treatments on the volatile profiles of white wines of feteasca regala

“…After 1 year from bottling time, the addition of carbon dioxide in the bottles did not influence significantly the aroma profile. All the sub-clusters containing wines with CO 2 overlapped with their corresponding sub-cluster without CO 2 , with the exception of the samples with both 40 mg/l GSH and 50 mg/l AA, which, as shown in other studies too [6,23] are the most prone to oxidation. Thus, we can see that after 1 year in bottle, without CO 2 protection, the wines containing a larger dose of GSH and in the presence of AA (group G40A) show different profiles of the volatile substances as compared to all the other wines.…”

Influence of Glutathione on Yeast Fermentation Efficiency under Copper Stress

“…18,19 However, GSH might play a role in the formation of sulfuric off-flavors 16 or the discoloration of white wines due to the formation of colored compounds. 20 A lack of studies exists on the complex interactions of yeast, copper stress, and GSH.…”

“…The use of GSH as an antioxidant in must and wine has recently received attention and its application is discussed controversially . Its inhibitory property against oxidative browning is well established, and the influence of GSH addition on the stability of aroma and color of wine has been reported. , However, GSH might play a role in the formation of sulfuric off-flavors or the discoloration of white wines due to the formation of colored compounds . A lack of studies exists on the complex interactions of yeast, copper stress, and GSH.…”