单选题
Men Smell of Cheese and Women of Onions
Little girls may be made of sugar and all things nice, but their armpits (腋部)
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of onions. And while free of slug or snail odours, men"s armpits pack a
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cheesy whiff. That"s the
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of research in Switzerland that involved taking armpit sweat samples from 24 men and 25 women after he had
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time in a sauna or ridden an exercise bike for 15 minutes.
The researchers found marked
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in the sweat from men and women. "Men smell of cheese, and women of grapefruit (葡萄柚) or onion," says Christian Starkenmann of Firmenich, a company in Geneva
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researches flavors and perfumes for food and cosmetics companies.
The team
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that the women"s armpit sweat constrained relatively high levels of an odourless sulphur-containning compound—5 milligrams per milliliter of sweat versus 0.5 milligrams in men.
When the researchers mixed this compound in the lab with bacteria commonly found in the armpit, the bugs turned it into a thiol (硫醇)—a previously discovered odour from armpits that is
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to onion.
"The more sulphur (硫) precursor we
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, the more intense was the malodour (难闻的 气味，恶臭)," says Starkenmann, whose team"s results appear in
Chemical Senses
. Bacterial enzymes (酶) turn the otherwise odourless precursor
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the malodour.
The men, meanwhile, had relatively high levels of an odourless fatty acid which turned into a cheesy odour when
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to the same types of bacteria. The balance of oniony to cheesy precursors in women"s sweat made it smell worse than men"s as rated by independent smell assessors.
Nest; the team hope to develop new ingredients for deodorants that
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the smells. "We could make inhibitors that neutralize the precursors, or block the bacterial enzymes that do the conversion," says Starkenmann.
Some researchers are skeptical that gender is the main deciding factor,
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that the patterns found in Swiss volunteers might not apply to other populations with different diets and genetic background. "Other factors
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what you eat, what you wash with, what you wear and what genes you
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," says Tim Jacob of Cardiff University in the U.K.