The enhancement of orange oil oxidation by sulphur dioxide

Reactions at 35°C of orange oil in contact with air and water were investigated by gas-liquid chromatography (g.l.c.) and by oxygen absorption measurements. Degradation of the orange oil was reduced in the presence of citric acid, but addition of sulphur dioxide caused a drastic increase, the extent and the rate of which were proportional to the initial concentration of the preservative. Several degradation products were identified.