Influence of glutathione oxidation and pH on thermal formation of Maillard-type volatile compounds

The Maillard-type volatile compounds obtained from the reaction of glutathione and glucose were mainly furans, carbonyl compounds, and sulfur-containing compounds including thiophenes, thiazoles, and cyclic polysulfides. Both pH 8.0 and 6.0 were favorable conditions for sulfur-containing compound formation, whereas acidic conditions were favorable for furan and derivative formation. The reaction between glutathionesulfonic acid, an oxidized form of glutathione, and glucose primarily produced furans, carbonyl compounds, pyrazines, and pyrroles. Furans dominated the products obtained from the reactions at pH 6.0 and 8.0. Pyrazines increased as the reaction pH increased. The disappearance of sulfur-containing compounds in the products of glutathionesulfonic acid and glucose reaction systems indicated glutathionesulfonic acid could not provide hydrogen sulfide for the reaction. Keywords: Glutathione; glutathionesulfonic acid; sulfur-containing; oxidation; pH