市售石榴汁的纯度鉴定
文章来源:未知 文章作者:meng 发布时间:2010-11-30 03:57 字体: [ ]  进入论坛
(单词翻译:双击或拖选)

You pick up a bottle of pomegranate juice(石榴汁) at the store because you've learned that, although it costs more than most juices, it is replete1(充满的) with antioxidants that bring health benefits. But wait: Is the juice you've purchased really pomegranate juice? Or is the product label you have carefully read promising2 more than it delivers? A chemist at the University of California, Riverside is determined3 to find out. Cynthia Larive, a professor of chemistry, is playing detective by applying chemical tests to juice products sold as pomegranate juice or pomegranate juice blends, in order to authenticate4(鉴定,证明) their contents.

"We are measuring levels of unique compounds in pomegranate juice and are able to use this 'molecular5 fingerprint6' to discriminate7 against adulterated(掺入次级品的) juice products," said Larive, whose research on pomegranate juice is being funded by a nearly $50,000 one-year grant from Pom Wonderful, a company that grows and markets pomegranates and pomegranate-based products.

In the lab, Larive and her graduate student Daniel Orr are measuring levels of different biochemicals, called small-molecule metabolites, present in juices. To make their measurements, the researchers are using nuclear magnetic resonance8 spectroscopy, liquid chromatography-mass spectroscopy, and gas chromatography-mass spectroscopy – three methods that together allow them to measure amino acids, organic acids, sugars, pomegranate pigment9 compounds, as well as health-producing antioxidant molecules10 that are unique to pomegranate juice.

"We have received a collection of pomegranate samples from around the world, as well as commercial juices such as beet11, grape, apple and pear – to name just a few," Larive said. "We're looking at whether or not our molecular fingerprint method can be used to identify products claiming to contain pomegranate juice when they don't, and products claiming to be pomegranate juice when they are not."

According to Larive, the three methods her lab used on pomegranate juices can be used to authenticate other products such as wine and olive oil by checking whether their metabolite profiles match what the products are claimed by their manufacturers to be.

"We are really curious to see how far we can push the technology," she said. "This research dovetails(吻合) nicely with some of the research we're already doing at UC Riverside on hypoxia(低氧) in plants with Julia Bailey-Serres. Where our experiments are concerned, juices, wine and olive oil are simply different sets of plant compounds. So it should be relatively12 easy to extrapolate(推断) the work we're doing on pomegranate juices to these products."

Larive explained that by examining the levels of different compounds in, say, pomegranate juice, a statistical13 picture – or chemical profile – emerges that describes the juice. Then, depending on how much an unknown product's profile differs from the pomegranate juice profile, her lab can determine whether that unknown product is pomegranate juice or contains only some or none of it.



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1 replete BBBzd     
adj.饱满的,塞满的;n.贮蜜蚁
参考例句:
  • He was replete with food and drink.他吃喝得饱饱的。
  • This immense space may be replete with happiness and glory.这巨大的空间可能充满了幸福和光荣。
2 promising BkQzsk     
adj.有希望的,有前途的
参考例句:
  • The results of the experiments are very promising.实验的结果充满了希望。
  • We're trying to bring along one or two promising young swimmers.我们正设法培养出一两名有前途的年轻游泳选手。
3 determined duszmP     
adj.坚定的;有决心的
参考例句:
  • I have determined on going to Tibet after graduation.我已决定毕业后去西藏。
  • He determined to view the rooms behind the office.他决定查看一下办公室后面的房间。
4 authenticate 0u4zr     
vt.证明…为真,鉴定
参考例句:
  • We would have to authenticate your relationship with the boy.我们必须证实一下您和那个孩子的关系。
  • An expert was needed to authenticate the original Van Gogh painting from his imitation.这幅画是凡·高的真迹还是赝品,需由专家来鉴定。
5 molecular mE9xh     
adj.分子的;克分子的
参考例句:
  • The research will provide direct insight into molecular mechanisms.这项研究将使人能够直接地了解分子的机理。
  • For the pressure to become zero, molecular bombardment must cease.当压强趋近于零时,分子的碰撞就停止了。
6 fingerprint 4kXxX     
n.指纹;vt.取...的指纹
参考例句:
  • The fingerprint expert was asked to testify at the trial.指纹专家应邀出庭作证。
  • The court heard evidence from a fingerprint expert.法院听取了指纹专家的证词。
7 discriminate NuhxX     
v.区别,辨别,区分;有区别地对待
参考例句:
  • You must learn to discriminate between facts and opinions.你必须学会把事实和看法区分出来。
  • They can discriminate hundreds of colours.他们能分辨上百种颜色。
8 resonance hBazC     
n.洪亮;共鸣;共振
参考例句:
  • Playing the piano sets up resonance in those glass ornaments.一弹钢琴那些玻璃饰物就会产生共振。
  • The areas under the two resonance envelopes are unequal.两个共振峰下面的面积是不相等的。
9 pigment gi0yg     
n.天然色素,干粉颜料
参考例句:
  • The Romans used natural pigments on their fabrics and walls.古罗马人在织物和墙壁上使用天然颜料。
  • Who thought he might know what the skin pigment phenomenon meant.他自认为可能知道皮肤色素出现这种现象到底是怎么回事。
10 molecules 187c25e49d45ad10b2f266c1fa7a8d49     
分子( molecule的名词复数 )
参考例句:
  • The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
  • Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里,大分子裂变为小分子。
11 beet 9uXzV     
n.甜菜;甜菜根
参考例句:
  • He farmed his pickers to work in the beet fields. 他出租他的摘棉工去甜菜地里干活。
  • The sugar beet is an entirely different kind of plant.糖用甜菜是一种完全不同的作物。
12 relatively bkqzS3     
adv.比较...地,相对地
参考例句:
  • The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
  • The operation was relatively painless.手术相对来说不痛。
13 statistical bu3wa     
adj.统计的,统计学的
参考例句:
  • He showed the price fluctuations in a statistical table.他用统计表显示价格的波动。
  • They're making detailed statistical analysis.他们正在做具体的统计分析。
TAG标签: research juice molecule
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