Why does cream go bad faster than butter? Some researchers think they have the answer, and it comes down to the structure of the

admin2016-06-22  28

问题     Why does cream go bad faster than butter? Some researchers think they have the answer, and it comes down to the structure of the food, not its chemical composition—a finding that could help rid some processed foods of chemical preservatives.
    Cream and butter contain pretty much the same substances, so why cream should sour much faster has been a mystery. Both are emulsions—tiny globules(小球)of one liquid evenly distributed throughout another. The difference lies in what’s in the globules and what’s in the surrounding liquid, says Brocklehurst, who led the investigation.
    In cream, fatty globules drift about in a sea of water. In butter, globules of a watery solution are locked away in a sea of fat. The bacteria which make the food go bad prefer to live in the watery regions of the mixture. "This means that in cream, the bacteria are free to grow throughout the mixture," he says.
    When the situation is reversed, the bacteria are locked away in compartments(密封舱)buried deep in the sea of fat. Trapped in this way, individual colonies cannot spread and rapidly run out of nutrients. They also slowly poison themselves with their waste products. "In butter, you get a self-limiting system which stops the bacteria growing," says Brocklehurst.
    The researchers are already working with food companies keen to see if their products can be made resistant to bacterial attack through alterations to the food’s structure. Brocklehurst believes it will be possible to make the emulsions used in salad cream, for instance, more like that in butter. The key will be to do this while keeping the salad cream liquid and not turning it into a solid lump.
According to the passage, which of the following statements is NOT true?

选项 A、Cream gets bad faster than butter due to their different food structures, not their chemical composition.
B、In cream, fatty globules drift about in a sea of water. In butter, globules of a watery solution are locked away in a sea of fat.
C、The researchers are working with food companies keen to see if their products can be made resistant to bacterial attack through substitutions of one or two ingredients.
D、It’s possible to prolong salad cream’s shelf life while keeping it liquid and not turning it into a solid lump.

答案C

解析 事实辨认题。解题依据在文章最后一段第一句话中,即研究人员正在接触食品厂商,努力通过改变食品的结构以使食品可以抵抗细菌的侵害。所以C中研究人员试图通过其他方法使食品可以抵抗细茵的侵害的说法是不对的,即C为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/RlQi777K
0

最新回复(0)