Inhibitory effect of betel quid on the volatility of methyl mercaptan

Betel quid, a popular natural masticatory in Taiwan, is mainly composed of fresh areca fruit, Piper betle (leaf or inflorescence), and slaked lime pas te. People say that halitosis disappears during betel quid chewing. In this study, the removal of mouth odor during betel quid chewing was discussed b y using a model systemwhich measured its inhibition on the volatility of me thyl mercaptan. Results showed that crude extracts of betel quid (the mixtu re of areca fruit, Piper betle, and slaked lime paste) and extracts of the mixture of areca fruit and slaked lime paste exhibited marked effects on th e volatility of methyl mercaptan, and the inhibition function increased whe n increasing amounts of slaked lime paste were added. The same condition (i ncreased inhibition) was also found by replacing the slaked lime paste with alkaline salts (calcium hydroxide, potassium hydroxide, or sodium hydroxid e). Areca fruit, the major ingredient of betel quid, contained abundant phe nolics. However, the crude phenolic extract of areca fruit did not show any inhibitory activity on the volatility of methyl mercaptan. Great inhibitor y activity occurred only when the crude phenolic extract of areca fruit was treated with alkali. Further studies by using gel filtration determined th at the effect probably came from the oxidative polymerization of phenolics of areca fruit after alkaline treatment.