Protection of some aroma volatiles in a model wine medium by sulphur dioxide and mixtures of glutathione with caffeic acid or gallic acid

摘要

Sulphur dioxide and mixtures of glutathione with caffeic acid or gallic acid were tested as inhibitors of the decrease of isoamyl acetate,ethyl hexanoate and linalool during storage of a model wine medium.Model wine samples were analysed by SPME and GC-MS.Isoamyl acetate,ethyl hexanoate and linalool decreased during storage of the model wine medium containing 0,20,40 or 60 mg/l free SO2.SO2 protected the three volatiles at 20(isoamyl acetate),40(ethyl hexanoate)and 60 mg/l(linalool).Mixtures of glutathione with caffeic acid or gallic acid were also protective;they were more active at 10 + 30 mg/l than at 5 + 15 mg/l.Glutathione + caffeic acid was more effective than glutathione + gallic acid.In most cases,SO2 at 40 mg/l increased the protective effect of the mixtures.SO2 at 60 mg/l exhibited protective ability comparable to that of glutathione + gallic acid 5 + 15 mg/l.The present results indicate that SO2 protects some wine aroma volatiles,but at high concentrations.On the other hand,mixtures of the wine constituents glutathione + caffeic acid or gallic acid are more effective at concentrations similar to those existing in wines.