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

    這是個眾所周知,且顯而易見的道理。

  • You can't unboil an egg.

    你無法還原一顆煮熟的雞蛋。

  • Well, it turns out you can, sort of.

    然而,在某種程度上,你其實是可以做到的。

  • What thermal energy does to the eggs' molecules, mechanical energy can undo.

    熱能對雞蛋的分子所做的事,其實可以靠機械動能將其還原。

  • Eggs are mostly made of water and proteins.

    蛋主要是由水和蛋白質組成。

  • The proteins start off folded up into intricate shapes, held together by weak chemical bonds.

    起初,蛋白質被折疊成一種複雜的形狀,依靠著薄弱的化學鍵連接在一起。

  • Adding heat disrupts those bonds, allowing the proteins to unfold, uncoil, unwind and wiggle freely.

    加熱會分解化學鍵,使蛋白質能夠展開、鬆繞、分離而自由地擺動。

  • This process is called denaturing.

    這個過程被稱為「變性」。

  • The newly liberated proteins bump up against their neighbors and start to form new bonds with each other, more and more as the heat increases,

    隨著熱能增加,新解放的蛋白質會與鄰近的蛋白質互相撞擊,並開始與對方形成新的鍵結,

  • until finally, they're so entangled that they gel into a solid mass: a boiled egg.

    直到最後它們糾結成一個膠狀固體:一顆水煮蛋為止。

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

    這種糾結看起來是永久性的,但其實並非如此。

  • According to a chemical idea called the principle of microscopic reversibility, anything that happens, like egg proteins seizing up, can theoretically unhappen, if you retrace your steps.

    根據一個叫做「微觀可逆原理」的化學原則,任何已發生的事情,像是雞蛋中的蛋白質變為固體的情況,只要我們倒著做每一步驟,理論上應該可以還原到最初狀態。

  • But adding more heat will tangle the proteins further, and cooling them down will only freeze them, so here's the trick: spin them around ridiculously fast.

    但是增加熱量只會使蛋白質糾纏的更緊,而降低溫度也只會冷凍住它們。所以要還原蛋白質的秘訣其實是:用極快的速度旋轉它們。

  • I'm not kidding.

    我沒在開玩笑。

  • Here's how it works.

    以下是它的原理。

  • First, scientists dissolve boiled egg whites in water with a chemical called urea, a small molecule that acts as a lubricant,

    首先,科學家在水中加入稱為尿素的化學物質,用來將煮熟的蛋白溶解在水裡。

  • coating the proteins' long strands and making it easier for them to glide past each other.

    尿素是一個小分子,好像潤滑劑一樣附著在蛋白質較長的一股,讓分子之間更容易互相滑過。

  • Then, they spin that solution in a glass tube at a breakneck 5000 rotations per minute, making the solution spread out into a thin film.

    然後,他們將溶液放入試管,並以一個每分鐘 5000 轉的極快速度旋轉,使得溶液展開形成一層很薄的生物膜。

  • Here's the key part.

    接下來是關鍵的部分。

  • The solution nearest the wall spins faster than the solution closer to the middle.

    離試管壁最近的溶液旋轉地比中間的溶液旋轉得更快,

  • That difference in velocity creates sheer stresses that repeatedly stretch and contract the proteins until eventually they snap back into their native shapes and stay there.

    而這個速度上的區別產生了壓力,會重複拉伸和收縮蛋白質,直到最後它們恢復成原始的形狀並穩定下來。

  • By the time the centrifuge stops spinning, the egg white is back in its original unboiled state.

    當離心機停止旋轉後,蛋白便恢復成了未被煮過的形態。

  • This technique works with all sorts of proteins.

    這個技術適用於所有種類的蛋白質。

  • Bigger, messier proteins can be more resistant to being pulled apart, so scientists attach a plastic bead to one end that adds extra stress and encourages it to fold up first.

    更大和更混亂的蛋白質將會更加難以還原,因此所以科學家會在其尾端黏上一個塑膠球,藉此產生額外的重量並加大收縮壓力,促使它先折疊。

  • This unboiling method won't work with a whole egg in its shell since the solution has to spread throughout a cylindrical chamber.

    這個方法不適用於一顆完整的帶殼水煮蛋,因為溶液必須在圓柱體容器內擴散開來才行。

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

    但是這項技術的實際應用方式,本來就遠遠超越還原早餐這樣的目的。

  • Many pharmaceuticals consist of proteins that are extremely expensive to produce, partly because they get stuck in tangled up aggregates,

    很多含有蛋白質的藥物的生產費用非常高昂,而部分是因為它們在聚集蛋白質時被卡住了,

  • just like cooked egg whites and have to be untangled and refolded before they can do their jobs.

    就像煮熟的蛋白那樣,它們必須被解開糾纏並重新摺疊之後才能發揮效用。

  • This spinning technique has the potential to be an easier, cheaper, and quicker method than other ways to refold proteins, so it may allow new drugs to be made available to more people faster.

    這種旋轉工法相比於其他再折疊蛋白質的方式還要更加容易、便宜且快速,因此這或許能讓新藥能以更快的速度送到更多人的手中。

  • And there's one more thing you need to keep in mind before trying to uncook all of your food.

    在想方設法還原你煮過的所有食物之前,有件事情你得記在心上。

  • Boiling an egg is actually an unusual cooking process because even though it changes the way proteins are shaped and bound together, it doesn't actually change their chemical identity.

    水煮雞蛋其實是個不太尋常的烹飪方法,因為雖然它改變了蛋白質的形狀和連接方式,卻沒有改變蛋白質的化學性質。

  • Most types of cooking are more like the famous Maillard reaction, which makes chemical changes that turn sugars and proteins into delicious caramel crunchiness and are a lot harder to undo.

    大多數的烹飪方法更類似著名的「梅納反應」,期間食物會發生化學變化,將糖質與蛋白質轉變為美味的焦糖色酥脆部分,而要回溯這樣的反應難度比回溯水煮蛋還要高得多。

  • So you might be able to unboil your egg, but I'm sorry to say you can't unfry it... yet.

    所以雖然你或許能還原眼前的水煮蛋,但很抱歉,你並不能還原煎荷包蛋... 至少目前還不行。

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

這是個眾所周知,且顯而易見的道理。

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B2 中高級 中文 美國腔

【TED-Ed】怎麼把水煮蛋變回生雞蛋?Eleanor Nelsen (【TED-Ed】How to unboil an egg - Eleanor Nelsen)

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    稲葉白兎 發佈於 2021 年 10 月 28 日
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