Inhibition of the decrease of volatile esters and terpenes during storage of a white wine and a model wine medium by glutathione and N-acetylcysteine

Glutathione and N-acetylcysteine, each at 20 mg L-1, were tested as inhibitors of the decrease of volatile esters and terpenes during storage of Debina white wine. Moreover, the inhibition of the decrease of isoamyl acetate, ethyl hexanoate and linalool in a model wine medium by glutathione and N-acetylcysteine, each at 0-20 mg L-1, was also tested. Several volatiles, such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and linalool, decreased during wine storage. Glutathione or N-acetylcysteine significantly restricted the decrease of these volatiles. In the model medium, each thiol inhibited the decrease of the three volatiles in a dose-dependent manner. N-acetylcysteine inhibited the decrease of all three volatiles at 2.5 mg L-1 while glutathione at 2.5 or 5.0 mg L-1. The present results indicate that glutathione and N-acetylcysteine may be taken into account as potent inhibitors of the disappearance of aromatic esters and terpenes in wines.