食物加工的重要性
文章来源:未知 文章作者:enread 发布时间:2016-03-10 05:47 字体: [ ]  进入论坛
(单词翻译:双击或拖选)
How much time and effort do you spend chewing? Although you probably enjoy a few leisurely1 meals every day, chances are that you spend very little time and muscular2 effort chewing your food. That kind of easy eating is very unusual. For perspective, our closest relatives, chimpanzees, spend almost half their day chewing, and with much greater force. 
 
When and how did eating become so easy? And what were its consequences? 
 
According to a new Harvard study, our ancestors between 2 and 3 million years ago started to spend far less time and effort chewing by adding meat to their diet and by using stone tools to process their food. The researchers estimate that such a diet would have saved early humans as many as 2.5 million chews per year, and made possible further changes that helped make us human. The study is described in a March 9 paper published in Nature. 
 
One of the biggest puzzles in human evolution is how species3 such as Homo erectus evolved smaller teeth, smaller faces, and smaller guts4, and yet managed to get more energy from food to pay for their bigger brains and bodies before cooking was invented. "What we showed is that...by processing food, especially meat, before eating it, humans not only decrease the effort needed to chew it, but also chew it much more effectively" said Katie Zink, the first author of the study, and a lecturer working in the lab of Daniel Lieberman, the Edwin M. Lerner II Professor of Biological Sciences. 
 
By changing their diets to include just 33 percent meat, and processing their food - slicing meat and pounding vegetables - before eating, Zink and Lieberman found that the muscular effort required per chew and the number of chews required per day was reduced by almost 20 percent. They also found that by simply slicing meat with the sorts of simple tools available more than 2 million years ago, humans were able to swallow smaller, more easily digestible pieces than would have been possible without using tools. 
 
"Eating meat and using stone tools to process food apparently5 made possible key reductions in the jaws6, teeth and chewing muscles that occurred during human evolution," Zink said.


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1 leisurely 51Txb     
adj.悠闲的;从容的,慢慢的
参考例句:
  • We walked in a leisurely manner,looking in all the windows.我们慢悠悠地走着,看遍所有的橱窗。
  • He had a leisurely breakfast and drove cheerfully to work.他从容的吃了早餐,高兴的开车去工作。
2 muscular l1qyK     
adj.肌肉发达的,强壮的,(有关)肌(肉)的
参考例句:
  • He is a muscular young man.他是个健壮的年轻人。
  • The player is tall and muscular.那名运动员身高力大。
3 species FTizN     
n.物种,种群
参考例句:
  • Are we the only thinking species in the whole of creation?我们是万物中惟一有思想的物种吗?
  • This species of bird now exists only in Africa.这种鸟现在只存在于非洲。
4 guts Yraziv     
v.狼吞虎咽,贪婪地吃,飞碟游戏(比赛双方每组5人,相距15码,互相掷接飞碟);毁坏(建筑物等)的内部( gut的第三人称单数 );取出…的内脏n.勇气( gut的名词复数 );内脏;消化道的下段;肠
参考例句:
  • I'll only cook fish if the guts have been removed. 鱼若已收拾干净,我只需烧一下即可。
  • Barbara hasn't got the guts to leave her mother. 巴巴拉没有勇气离开她妈妈。 来自《简明英汉词典》
5 apparently tMmyQ     
adv.显然地;表面上,似乎
参考例句:
  • An apparently blind alley leads suddenly into an open space.山穷水尽,豁然开朗。
  • He was apparently much surprised at the news.他对那个消息显然感到十分惊异。
6 jaws cq9zZq     
n.口部;嘴
参考例句:
  • The antelope could not escape the crocodile's gaping jaws. 那只羚羊无法从鱷鱼张开的大口中逃脱。
  • The scored jaws of a vise help it bite the work. 台钳上有刻痕的虎钳牙帮助它紧咬住工件。
TAG标签: species food tools
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