Methods: Forty subjects were divided into 4 groups; 10 in each group. In each experiment, 4 Thai culinary ingredients, namely garlic, celery, shallot, and coriander were randomly assigned to the 4 groups. Subjects were requested to refrain from consuming odorous food or wearing the perfume or scented cosmetics 1 day before the experiment. On the experiment day, VSCs consisting of Hydrogen sulfide, Methyl mercaptan Dimethyl sulfide were measured by Oral Chroma and recorded as baseline value (Tb). Subjects in each group subsequently chewed and spread each Thai culinary ingredient in their mouths for 1 min and subsequently spitted out. VSCs were then recorded again at 0, 15 and 30 min. After a wash-out period of 1 week, subjects randomly changed to another Thai culinary ingredient and VSCs were measured by the same procedure until they completed all the 4 culinary ingredients. Data were analyzed by appropriate statistics.
Results: All 3 VSCs of garlic and shallot elicited statistically higher values than Tb. Celery revealed statistically higher hydrogen sulfide and methyl mercaptan than Tb, while coriander demonstrated statistically higher methyl mercaptan and dimethyl sulfide than Tb.
Conclusions: Halitosis from 4 Thai culinary ingredients results from different VSC compositions.