Effects of pH Adjustment and Subsequent Heat Treatment on the Formation of Volatile Compounds of Garlic

Effects of pH adjustment during the blending of garlic cloves and subsequence heat treatment on the formation of volatile compounds of garlic were studied by means of gas chromatography (GC). The formation of the two isomeric cyclic compounds 3-vinyl-4H]-l,2-dithiin and 2-vinyl-4H]-l,3-dithiin, which were artifacts from allicin, was favored around pH 5.5. Formation of diallyl trisulfide, methyl allyl trisulfide, cis-1-propenyl allyl disulfide, isobutyl isothiocyanate, 2,4-dimethylfuran, 1,3-dithiane, aniline, methyl allyl sulfide, dimethyl disulfide and 3-methyl-2-cyclopentene-l-thione were favored in neutral or weak acidic conditions, whereas formation of diallyl disulfide, diallyl sulfide, methyl allyl disulfide, propenylthiol, propyl allyl disulfide and 1,2-epithiopropane were favored around pH 9.0.