How to unboil an egg - Eleanor Nelsen

翻译人员: Cissy Yun 校对人员: Zongzhen Yang

It's so obvious that it's practically proverbial.

很明显又众所周知的是

You can't unboil an egg.

你不能把一个熟蛋变生

Well, it turns out you can, sort of.

然而，其实在某种程度上， 你是可以的

What thermal energy does to the eggs' molecules,

热能对蛋的分子所做的事

mechanical energy can undo.

机械能可以将其还原

Eggs are mostly made of water and proteins.

蛋主要是由水和蛋白质组成

The proteins start off folded up into intricate shapes,

蛋白质最开始折叠成一种复杂的形状

held together by weak chemical bonds.

依靠弱的化学键连接在一起

Adding heat disrupts those bonds,

加热能分解化学键

allowing the proteins to unfold, uncoil, unwind and wiggle freely.

使的蛋白质展开，松绕，分离， 变得可以移动

This process is called denaturing.

这个过程被称为“改性”

The newly liberated proteins bump up against their neighbors

新的被解放的蛋白质互相撞击

and start to form new bonds with each other,

并在其中形成新的化学键

more and more as the heat increases,

当热量变得越来越多后

until finally, they're so entangled that they gel into a solid mass,

到达某一刻时，蛋白质之间的精密缠绕， 最终形成一个固体

a boiled egg.

就是煮熟的蛋

That entanglement might look permanent, but it's not.

这个过程可能看起来不可逆， 但其实不是的

According to a chemical idea

根据一个叫做

called the principle of microscopic reversibility,

微观可逆原理的化学观点

anything that happens, like egg proteins seizing up,

任何已发生的， 比如说鸡蛋中的蛋白质变为固体的情况

can theoretically unhappen if you retrace your steps.

如果你反之重复每一步，理论上可以反转

But adding more heat will tangle the proteins further,

但增加更多的热量会使蛋白质纠缠的更紧

and cooling them down will only freeze them,

而冷却只会冻住它们

so here's the trick:

所以这里的窍门是

spin them around ridiculously fast.

将其极快的旋转

I'm not kidding.

我没在开玩笑

Here's how it works.

它们是这样做的

First, scientists dissolve boiled egg whites in water

首先，科学夹将煮熟的蛋白溶解在水中

with a chemical called urea,

加以一种化学物质，尿素

a small molecule that acts as a lubricant, coating the proteins' long strands

它是一个小分子，被用作润滑剂， 涂上蛋白质较长的一股

and making it easier for them to glide past each other.

使得它们更容易得滑过对方

Then, they spin that solution in a glass tube

然后，他们将溶液放入试管以

at a breakneck 5000 rotations per minute,

一个极快的5000转每分钟的速度旋转

making the solution spread out into a thin film.

使得溶液展开形成一层很薄的生物膜

Here's the key part.

接下来是关键的部分

The solution nearest the wall spins faster

离试管壁最近的溶液旋转地比

than the solution closer to the middle.

中间的溶液旋转得快

That difference in velocity creates sheer stresses

这个速度上的区别产生了剪应力

that repeatedly stretch and contract the proteins

会重复拉伸和收缩蛋白质

until eventually they snap back into their native shapes and stay there.

直到最后它们恢复成原始的性状， 并稳定下来

By the time the centrifuge stops spinning,

当离心机停止旋转

the egg white is back in its original unboiled state.

鸡蛋白恢复成了未被煮过的形态

This technique works with all sorts of proteins.

这个技术适用于所有蛋白质

Bigger, messier proteins can be more resistant to being pulled apart,

更大和更混乱的蛋白质将会更难还原

so scientists attach a plastic bead to one end

所以科学家会在蛋白质一股的一端 黏上一个塑料珠

that adds extra stress and encourages it to fold up first.

产生额外的重量，并会加大收缩 促使它先折叠

This unboiling method won't work with a whole egg in its shell

这个方法不适用于一个完整的带壳的蛋

since the solution has to spread throughout a cylindrical chamber.

因为溶液必须在圆柱体容器内展开

But the applications go way beyond uncooking your breakfast, anyhow.

但它的应用远超出仅是还原你的早餐

Many pharmaceuticals consist of proteins that are extremely expensive to produce,

很多含有蛋白质的药物的生产费用非常高

partly because they get stuck in tangled up aggregates,

有些是因为他们卡在了聚集蛋白质中

just like cooked egg whites

就像煮熟的蛋白

and have to be untangled and refolded before they can do their jobs.

这些必须在他们开始工作前被打散和展开

This spinning technique has the potential

这个旋转方法， 相比于其他再折叠蛋白质的方式

to be an easier, cheaper and quicker method

有着成为一个更简单，便宜，快速的方法

than other ways to refold proteins,

的潜力

so it may allow new drugs to be made available to more people faster.

所以，它可能会使新药物的出现更加快捷

And there's one more thing you need to keep in mind

还有一个事情你需要记住

before trying to uncook all of your food.

在还原你的食物之前

Boiling an egg is actually an unusual cooking process

煮蛋实际上是个不寻常的过程

because even though it changes the way proteins are shaped and bound together,

因为即使它使蛋白质的形状和连接方式 发生了改变

it doesn't actually change their chemical identity.

它的化学性质并没有改变

Most types of cooking are more like the famous Maillard reaction,

大多数烹饪过程类似著名的“梅拉德反应”

which makes chemical changes

就是会发生化学变化

that turn sugars and proteins into delicious caramel crunchiness

将糖分和蛋白质转换成美味的焦糖脆

and are a lot harder to undo.

这会非常难还原

So you might be able to unboil your egg,

所以你可以还原你的煮蛋

but I'm sorry to say you can't unfry it...yet.

但很抱歉，目前为止， 还不能还原你的煎蛋