And for good reason. Add these foods to your gelatin, and it won't set.

這是有原因的。如果你添加這些東西, 果凍就不會凝固。

It will remain a big, goopy mess.

它會維持一大坨黏稠的型態。

The reason why is pretty straightforward, but if you understand it, it can help you learn how to make better desserts, and how to up your cooking game in general.

原因很簡單, 了解這個原因可以幫助你做出更棒的甜點, 並提升你的烹飪技術。

To understand why these fruits ruin gelatin, you need to know what this stuff is made of.

要了解這些水果破壞果凍的原因, 你得知道這種物質是由什麼組成的。

Once it sets, gelatin is basically a mesh of interconnected collagen molecules.

一旦凝固, 明膠基本上就是一團互相連結的膠原蛋白分子。

Collagen is a long, fibrous protein found in things like skin and bones.

膠原蛋白是一種長纖維狀蛋白質, 存在於皮膚和骨骼中。

And… yes, the collagen in gelatin does traditionally come from animals.

沒錯, 明膠的膠原蛋白最初的確源自於動物。

Manufacturers boil things like hides or bones until the proteins come out, and then they turn them into a powder you can buy at the store for, like, a dollar.

製造商將獸皮或骨頭之類的東西煮沸, 直到其產生蛋白質為止, 然後將其製成商店裡約賣1美元的粉末。

When you dissolve the powder in hot liquid, the collagen separates into individual fibers.

當粉末在熱液體中溶解時, 膠原蛋白會變成單獨的纖維。

Then, as the solution cools, those fibers start to bind to one another and gradually form a mesh.

然後, 在溶液冷卻的過程中, 這些纖維開始互相連接, 逐漸形成網狀結構。

But if you add certain fruits as you're making your gelatin, that last process will never happen.

但如果在製作果凍時添加某些水果, 最後的步驟就不會成功。

It's because fresh kiwi, pineapple, and some other fruits contain high concentrations of proteases, or proteolytic enzymes.

這是因為新鮮的奇異果、鳳梨和一些其他水果含有高濃度的蛋白酶或水解酶。

These are substances that digest proteins, basically, chopping them into tiny pieces.

這些物質會分解蛋白質, 基本上就是將其切成碎片。

If this stuff gets into your gelatin mix, it will cut up those strands of collagen until they're too short to link together, so your dessert will come out looking like a soup.

這些物質被加入果凍混合物中後, 它們就會切斷膠原蛋白纖維, 使其因為太短而無法相連, 讓你的甜點看起來像湯一樣。

If you know why this happens though, it's easy to find some ways to work around it.

但如果你知道它的原理, 你就能輕易地想到對策。

For one, if you cook the fruit, the heat will inactivate those enzymes, so your gelatin will turn out just fine.

首先, 如果你烹煮水果, 熱度會使酶失去活性, 那麼用來做果凍就沒問題。

This is also why something like canned pineapple doesn't cause issues.

因此鳳梨罐頭就不會有這些問題。

Alternatively, you could make your dessert with agar instead of gelatin.

或者你做甜點時, 可以用瓊脂代替明膠。

Agar is made from certain types of red algae, and like gelatin, it forms an interconnected meshwork of fibers.

瓊脂由某種紅藻製成, 和明膠一樣, 會形成互相連接的纖維網。

But it's made of carbohydrates, not proteins, so proteases won't digest it.

但它是由碳水化合物製成, 而不是蛋白質, 所以不會被酶分解。

Of course, while these fruity enzymes aren't great for gelatin, they do have their uses.

當然, 雖然水果酶對果凍沒有幫助, 它們有其他用途。

For one, they have some surprising industrial and medical benefits.

首先, 它們具有令人驚豔的工業和醫療效益。

Like, they can be used to prep damaged areas for skin grafts if someone gets a severe burn.

例如, 如果有人嚴重燒傷, 就能使用它們為受損區域的皮膚移植做準備。

The treatment breaks down and clears away dead and damaged tissue.

這種處理方式能分解並清除壞死和受損的組織。

But maybe more importantly to you, you can also use juice or pulp from protease-containing fruits in the kitchen to tenderize tough cuts of meat.

但也許對你來說更重要的是, 你也可以用廚房裡含有蛋白酶的果汁或果肉軟化肉塊。

The enzymes break down stringy bundles of proteins, making the meat easier to chew.

酶可以分解纖維狀的蛋白質, 讓肉更容易咀嚼。

So, go ahead and save that fresh pineapple for your steak, and stick to the canned stuff when it comes to gelatin. Everyone will thank you.

所以, 把新鮮的鳳梨留到料理牛排時再用, 製作果凍時用罐頭就好。大家一定會感謝你！

If you want to learn more science-inspired cooking hacks, we've got an episode with seven more of them for you.

如果你想了解更多受科學啟發的烹飪技巧, 我們還有一集影片提供了七種妙方。

And as always, thank you for watching this episode of SciShow!

一如既往, 感謝各位收看本期的 SciShow。