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Dimethyl Sulphide, A background flavor compound that is desirable in low amounts in lagers, but that at high concentrations tastes of cooked vegetables. | Dimethyl Sulphide, A background flavor compound that is desirable in low amounts in lagers, but that at high concentrations tastes of cooked vegetables. | ||
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| + | '''What sort of smell does dimethyl sulphide have?''' | ||
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| + | It has been described as extremely unpleasant, as it is a substance added to odourless gases (like natural gas) as an odouriser, so that leaks can be detected. Others say that the smell is at least in part due to impurities, such as polysulphides, and that pure dimethyl sulphide has a more pleasant smell ("sweetcorn"). The odour may also depend upon concentration. | ||
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| + | '''Cooked cabbageDoes it crop up anywhere else?''' | ||
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| + | Recent research reveals dimethyl sulphide to be one of the main odour components (along with H2S and CH3SH) of human flatus. It has been found to be an odour component of some beers (germinating barley produces S-methyl methionine, a source of (CH3)2S), and is responsible for the smell of cooked cabbage (picture right), possibly from bacterial metabolism of methionine or S-methylmethionine, present in large quantities in brassicas. It has also been associated with the rotting smell of dead-horse arum florets, which fools flies into pollinating it by emitting a smell like a dead animal. It is produced by some sponges, though probably not as a protection against fish predators, but with other defensive functions (e.g. antimicrobial, antifouling). And you may smell it in the bracing air at the seaside! | ||
Revision as of 10:54, 22 July 2007
Dimethyl Sulphide, A background flavor compound that is desirable in low amounts in lagers, but that at high concentrations tastes of cooked vegetables.
What sort of smell does dimethyl sulphide have?
It has been described as extremely unpleasant, as it is a substance added to odourless gases (like natural gas) as an odouriser, so that leaks can be detected. Others say that the smell is at least in part due to impurities, such as polysulphides, and that pure dimethyl sulphide has a more pleasant smell ("sweetcorn"). The odour may also depend upon concentration.
Cooked cabbageDoes it crop up anywhere else?
Recent research reveals dimethyl sulphide to be one of the main odour components (along with H2S and CH3SH) of human flatus. It has been found to be an odour component of some beers (germinating barley produces S-methyl methionine, a source of (CH3)2S), and is responsible for the smell of cooked cabbage (picture right), possibly from bacterial metabolism of methionine or S-methylmethionine, present in large quantities in brassicas. It has also been associated with the rotting smell of dead-horse arum florets, which fools flies into pollinating it by emitting a smell like a dead animal. It is produced by some sponges, though probably not as a protection against fish predators, but with other defensive functions (e.g. antimicrobial, antifouling). And you may smell it in the bracing air at the seaside!
