Characteristic flavor constituents in water extract of garlic.

The flavoring effects of a water extract of garlic (Allium sativum L.) being added to common soups (Chinese soup and curry soup) were examined by a sensory evaluation. When a small amount (0.1 or 0.4% w/v) of the extract was added to the soups, it showed characteristic kokumi flavors (continuity, mouthfulness, and thickness), and other tests revealed that this effect was clearly recognized in the umami solution composed of 0.05 % w/v of monosodium glutamate and 0.05 % w/v of disodium inosinate. To find the key compounds which gave rise to the effect, the water extract was chromatographed on Duolite C-25 and the adsorbed fraction showed the activity. Further chromatographic studies of the fraction showed that the key compounds were sulfur-containing components, such as alliin, (+)-S-methyl-L-cysteine sulfoxide, and γ-L-glutamyl-S-allyl-L-cysteine.