TED演讲:辣味的科学(1)

　　Why does your mouth feel like it's on fire when you eat a spicy¹ pepper? 为什么吃辣椒时嘴里像是着了火一样？

　　And how do you soothe² the burn? 怎样才能缓解这种灼烧感？

　　Why does wasabi make your eyes water? 为什么芥末酱能让人流泪？

　　And how spicy is the spiciest³ spice? 最辣的辛香料究竟有多辣？

　　Let's back up a bit. First, what is spiciness⁴? 让我们从头说起。首先想一个问题：什么是辣味？

　　Even though we often say that something tastes spicy, it's not actually a taste, like sweet or salty or sour. 我们常说一些食物很辣但实际上辣并不是一种味道它不同于甜、咸、酸这些可以尝到的味道。

　　Instead, what's really happening is that certain compounds in spicy foods activate⁵ the type of sensory⁶ neurons called polymodal nociceptors. 之所以会感到辣是因为辛辣食物中的一些复合物激活了人体中一种叫“伤害性感受器”的感觉神经元。

　　You have these all over your body, including your mouth and nose, and they're the same receptors that are activated⁷ by extreme heat. 这种神经元遍布全身，包括嘴巴和鼻子，值得一提的是，当身体接触到热烫物体时也能激活这种神经元。

　　So, when you eat a chili⁸ pepper, your mouth feels like it's burning because your brain actually thinks it's burning. 当你吃辣椒时，嘴里之所以像是着了火是因为大脑的确认为嘴里起火了。

　　The opposite happens when you eat something with menthol in it. 而如果这时再吃一些含薄荷醇的食物，嘴里就会有相反的感觉，灼烧感会缓解很多。

　　The cool, minty compound is activating⁹ your cold receptors. 这是因为凉凉的薄荷味复合物激活了你的冷觉感受器。

　　When these heat-sensitive receptors are activated, your body thinks it's in contact with a dangerous heat source and reacts accordingly. 当热敏感受器被激活，会认为你贴近了危险的热源，身体会做出一定的反应。

　　This is why you start to sweat, and your heart starts beating faster. 因此这时你会开始流汗心跳加速。

　　The peppers have elicited¹⁰ the same fight-or-flight response with which your body reacts to most threats. 吃辣椒引起的身体本能反应跟身体应对危险状况的本能反应是一样的。

　　But you may have noticed that not all spicy foods are spicy in the same way. 你可能已经发现不同辣食的辣味各有不同。

　　And the difference lies in the types of compounds involved. 食物中的不同复合物形成了不同的辣味。

　　The capsaicin and piperine, found in black pepper and chili peppers,  比如，黑胡椒和红辣椒中含有的辣椒素和胡椒碱是由一种叫“烷基胺”的分子组成的，

　　are made up of larger, heavier molecules¹¹ called alkylamides, and those mostly stay in your mouth. 这种分子较大、较重能滞留在嘴中。

　　Mustard, horseradish, and wasabi are made up of smaller molecules, called isothiocyanates, that easily float up into your sinuses. 而芥末酱、辣根酱、芥末酱中含有一种叫“异硫氰酸盐”的分子这种分子较小能轻松扩散到鼻窦处。

　　This is why chili peppers burn your mouth, and wasabi burns your nose. 所以，吃红辣椒时，嘴里会有灼烧感而吃芥末酱时，鼻子里会有灼烧感。

1 spicy   

adj.加香料的；辛辣的，有风味的

参考例句：

• The soup tasted mildly spicy.汤尝起来略有点辣。
• Very spicy food doesn't suit her stomach.太辣的东西她吃了胃不舒服。

2 soothe   

v.安慰；使平静；使减轻；缓和；奉承

参考例句：

• I've managed to soothe him down a bit.我想方设法使他平静了一点。
• This medicine should soothe your sore throat.这种药会减轻你的喉痛。

3 spiciest   

adj.用香料调味的( spicy的最高级 )；有香料味的；有刺激性的；（故事、新闻等） 刺激的

参考例句：

4 spiciness   

n.香馥，富于香料；香味

参考例句：

• For that extra spiciness, add powdered nutmeg to taste. 至于要得到那种额外的香味，酌量加入肉豆蔻粉。 来自互联网
• Aside from a graph a thermometer will be used to show spiciness. 除了文字标记以外，还将用温度表图像形象地表达辣度。 来自互联网

5 activate   

vt.使活动起来，使开始起作用

参考例句：

• We must activate the youth to study.我们要激励青年去学习。
• These push buttons can activate the elevator.这些按钮能启动电梯。

6 sensory   

adj.知觉的，感觉的，知觉器官的

参考例句：

• Human powers of sensory discrimination are limited.人类感官分辨能力有限。
• The sensory system may undergo long-term adaptation in alien environments.感觉系统对陌生的环境可能经过长时期才能适应。

7 activated   

adj. 激活的 动词activate的过去式和过去分词

参考例句：

• The canister is filled with activated charcoal.蒸气回收罐中充满了活性炭。

8 chili   

n.辣椒

参考例句：

• He helped himself to another two small spoonfuls of chili oil.他自己下手又加了两小勺辣椒油。
• It has chocolate,chili,and other spices.有巧克力粉，辣椒，和其他的调味品。

9 activating   

活动的，活性的

参考例句：

• "I didn't say we'd got to stop activating the masses! “我并没说就此不发动！ 来自子夜部分
• Presumably both the very small size and activating influence of fluorine atoms contribute to this exception. 这大概是由于氟原子半径小和活性高这两个原因的影响，氟原子对这种例外做出了贡献。

10 elicited   

引出，探出( elicit的过去式和过去分词 )

参考例句：

• Threats to reinstate the tax elicited jeer from the Opposition. 恢复此项征税的威胁引起了反对党的嘲笑。
• The comedian's joke elicited applause and laughter from the audience. 那位滑稽演员的笑话博得观众的掌声和笑声。

11 molecules   

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。