Liken the black spots on bananas to the liver spots on mature
adult, they appear with age, even if they go untouched. The hormone ethylene, a ripening
agent found in the skin of the banana, transforms a green
banana into the appealing yellow fruit we purchase at the
market.
Ethylene, however, continues the ripening process, which gives
the banana a "bruised" appearance, and eventually turns the banana
black in color. There is no switch to turn off this process, but by
placing the banana in a cool place, one can slow the process. The
refrigerator is no place for a banana, because this is certain to
blacken it prematurely. The cold air, to which the banana is
exposed, causes the production of blackening compounds known as
polyphenols.
Did you know?
In North America more bananas are eaten every day than any other
fruit.
Bananas aren't grown on trees. They're part of the
lily family, a cousin of the orchid, nothing but a very yellow and plump
member of the herb family. With stalks 25 feet high, they're the
largest plant on earth without a woody stem.
The word banana
is African, though, a word carried to the New World by Portuguese
slave traders. In Alexander the Great's time, bananas were called
"pala" in Athens.
North America got its first taste of the
tropical fruit in 1876 at the Philadelphia Centennial Exhibition.
Each banana was wrapped in foil and sold for 10 cents. |
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note:
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hormone: 荷尔蒙
ethylene: 乙烯
ripening agent: 催熟剂
polyphenol: 多酚
lily family: 百合科
orchid:
兰花
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