Protective effect of thiols on wine aroma volatiles.

The ability of glutathione, oxidized glutathione, N-acetyl-cysteine, and N-acetyl-serine to protect wine aroma volatiles was examined. Muscat-white and Xinomavro-red wine were stored in open bottles at 20 o C and aroma volatiles were determined using solid phase microextraction along with GC-MS. Glutathione and N-acetyl-cysteine inhibited the decrease of several ace- tate esters, ethyl esters and terpenols, while oxidized glutathione and N-acetyl-serine did not. Present results show that the free -SH is responsible for the ability of glutathione and N-acetyl-cysteine to protect white and red wine aroma volatiles. Consequently, the protective action of any thiol in any wine may be taken into account.