Volatile Compounds in Stir-Fried Garlic

Abstract

Stir-fried garlic was extracted by supercritical CO 2 at 200 kg/cm 2 and 40 °C. The extract contained only ∼1% of the original frying oil. The volatile compounds of the extract were then analyzed by the purge and trap method and by the simultaneous distillation and extraction method. Dimethyl sulfide, allyl alcohol, diallyl sulfide, methyl allyl disulfide, and diallyl disulfide were the major volatile compounds found by headspace gas analysis. On the other hand, the major volatile compounds of stir-fried garlic isolated by simultaneous distillation and extraction were diallyl disulfide, diallyl trisulfide, and dithiins. The advantages and disadvantages of these flavor isolation methods are discussed and compared with published data. The lower thermal effect of the headspace gas analysis resulted in no propyl sulfides and heterocyclic compounds being found and a higher yield of low-boiling-point compounds. The total percentage of vinyldithiins of stir-fried garlic was >30% as isolated by the simultaneous distillation and extraction method ; however, vinyldithiins were still not significantly recovered, even when the purge time was prolonged to 35 min.