Release of volatile compounds from microwave heating of garlic juice with 2,4-decadienals

Garlic (Allium sativum L.) juice and 2,4-decadienals were heated in a microwave oven at the full power of 700 W. The volatile compounds of heated samples were isolated using diethyl ether solvent extraction and analysed using gas chromatography and gas chromatography-mass spectrometry. A total of 23 compounds were identified from these samples, among which 14 sulfide compounds, five aldehydes, two alcohols, one acid and one furan were identified. Three tentatively identified compounds, dithio(1-propenyl)propionate, dihydro-2(3H)-thiophenthione and n-hexanethiol were newly found in deep-fried garlic flavor. During microwave heating, levels of most volatiles decreased as the heating time continued. 2-Pentylfuran, isopropyl alcohol, hexanal and (E)-2-octenal were formed from the degradation of 2,4-decadienals. Sulfur dioxide was generated predominantly from the degradation and oxidation of sulfide compounds. (C) 1999 Elsevier Science Ltd. All rights reserved.