美国科学60秒 SSS 2013-02-13
时间:2013-07-23 03:21:38
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(单词翻译)
Too little salt makes for(导致) a bland(温和的;乏味的) meal. But too much is offensively briny1(海水的;咸的). Now, scientists have discovered why too much tastes bad. The work is in journal Nature.
As the previous podcast
noted2, the cells that process taste send a unique signal to the brain for each kind of flavor. The signals for sweet and umami make animals
crave3 more, while sour and bitter are often rejected. But saltiness is appealing in low doses and aversive at high levels. The researchers found out why: too much salt
activates4 the cells that sense sourness and bitterness, sending unpleasant signals to the brain and transforming a tasty bite into a turn-off(使厌烦).
The study used mice unable to taste sourness, bitterness, or both. Animals that could still sense one of the flavors rejected overly salty water. But mice unable to taste sour and bitter were happy to lick up liquid that was far too briny for normal animals.
With salt being a variable flavor, our bodies can better keep its levels within a healthful range. And leave a good taste in the mouth.
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