QQs: Why Is Red Meat...Red?
快問快答：為什麼紅肉...是紅的？
It's kind of unavoidable—if you cut into a big, juicy, rare steak, you're gonna get some juice. Watery red liquid seeps out of the meat and onto the plate and...it kinda looks like blood. But I have good news for people who like to eat red meat but don't like to eat blood: It's not blood. It's just water, plus a handy protein called "myoglobin."
這有點難以避免－－如果你切進一塊又大又多汁的一分熟牛排，你會看到一些肉汁。水水的紅色液體從肉中滲出然後流到盤子上...那看起來有點像血。不過我有好消息給那些愛吃紅肉但不愛吃血水的人：那不是血。那只是水，加上一種叫作「肌紅素」的有用蛋白質。
All meat is muscle, but the muscle looks different depending on what it's used for. White meats, like turkey and chicken, come from muscles that are used in short spurts every so often, but have to get moving quickly. Think of a chicken breast. They don't actually use their wings very often.
所有的肉都是肌肉，不過肌肉的外表會視其作用而有所不同。白肉，像是火雞肉和雞肉，來自偶爾用來快速衝刺但得快速動起來的肌肉。想想雞胸肉。雞其實並不常使用牠們的翅膀。
Red meats, like beef, lamb, and even pork, come from muscles used for long, strenuous activities, like carrying a huge cow around all the time. Before cooking, these meats are a pinky-reddish color. Holding up a heavy cow is some serious work, work that requires a lot of oxygen for fuel, which is where myoglobin comes in.
紅肉，像是牛肉、羊肉，甚至是豬肉，來自用來進行冗長費力活動的肌肉，像是一直帶著一隻大牛走來走去。在煮之前，這些肉呈現一種紅中帶粉的顏色。支撐一隻沉重的牛是很累人的工作，需要許多氧當燃料的工作，這就是肌紅素發揮功能的地方了。
Myoglobin is a special protein with an iron atom at its center, which bonds with, then stores and delivers oxygen to muscle cells. It works together with hemoglobin, another oxygen carrier, to get oxygen to the cells that need it. The difference between red meat and white meat comes from the levels of myoglobin in the muscle. The myoglobin protein itself is red, so the more myoglobin in the cells, the redder the meat appears. And that juice that's spilling out of your meat? That's a combination of water and myoglobin. The animal's blood was removed when the meat was processed.
肌紅素是種中心有個鐵原子的特殊蛋白質，它能夠結合然後儲存並運送氧氣到肌肉細胞中。它和血紅素合作，血紅素是另一種攜氧蛋白質，一同將氧氣帶到有需要的細胞。紅肉和白肉的差異是因為肌肉中肌紅素含量不同的緣故。肌紅蛋白本身是紅的，因此細胞中有越多肌紅素，肉看起來就越紅。而從你的肉中溢出的那種肉汁呢？那是水和肌紅素的混合。動物的血在肉被處理時就清掉了。
Beef is around 0.8 percent myoglobin, and lamb has a little less, at 0.6 percent. And all of those ads have been lying to you, because at 0.2 percent myoglobin, pork is generally considered red meat, too. Chicken only has about a quarter of that amount. But what about humans? Well, our flesh is about as red as red meat can get—at two percent myoglobin.
牛肉的肌紅素含量約是 0.8%，羊肉少一點，0.6%。而所有廣告一直以來都在騙你，因為肌紅素含量 0.2%，豬肉通常也被視為紅肉。雞肉的含量大概只有那的四分之一。但人類呢？嗯，我們的肉大概是紅肉最紅的程度吧－－肌紅素含量百分之二。
If you happen to like steak, but you don't want red juice, you have options. Myoglobin is red when it's bonded with oxygen. When meat is cooked rare, up to about 60 degrees Celsius, the color stays. Above that temperature, the iron atom in myoglobin loses an electron, and therefore its ability to bind with oxygen. Instead, the myoglobin forms a new molecule called "hemochrome" that gives medium and well-done meat it's brown-gray color. Myoglobin will also turn brown if it's exposed to air for long enough, because that makes the iron atoms lose an electron too, which is why checking the color can be a handy way to tell if your store-bought meat is still fresh.
如果你剛好愛吃牛排，但不想要有紅色肉汁的話，你有選擇。肌紅素在和氧氣結合時是紅的。當肉被煮成一分熟，大約接近攝氏六十度時，那顏色還在。高於那溫度，肌紅素中的鐵原子失去一個電子，因此失去與氧結合的能力。取而代之，肌紅素會形成一個叫作「血色素」的新分子，它帶給五分熟和全熟肉那種棕灰的色澤。肌紅素若曝露在空氣中夠久也會變成棕色，因為那也會使鐵原子失去一個電子，這就是為什麼檢查顏色可以是種看出從店內買的肉是否還新鮮的簡便方法。
It doesn't always work, though, because some meat producers add compounds that keep the meat red, and the color can last way past the expiration date. But if you do end up buying that red meat and cooking it rare, I hope you enjoy your oxygen-rich protein water.
不過那不總是有用，因為有些肉品製造商會添加能讓肉保持鮮紅的化合物，而那顏色能維持到保存期限過很久後。不過如果你最後真的買了那紅肉然後煮成一分熟，希望你好好享用那富含氧的蛋白質水。
Thanks for asking, and thanks especially to all of our patrons on Patreon who keep these answers coming. If you'd like to submit questions to be answered or get these Quick Questions a few days before everyone else, go to patreon.com/scishow. And don't forget to go to youtube.com/scishow and subscribe.
謝謝發問，然後特別感謝在 Patreon 上讓我們能持續解惑的所有贊助人們。如果你想提交希望得到解答的問題，或早別人幾天看到這些快問快答的話，就到 patreon.com/scishow。別忘了到 youtube.com/scishow 並訂閱喔。
- 「偶爾、有時」- Every So Often
White meats, like turkey and chicken, come from muscles that are used in short spurts every so often, but have to get moving quickly.
白肉，像是火雞肉和雞肉，來自偶爾用來快速衝刺但得快速動起來的肌肉。 - 「支撐、抬起來」- Hold Up
Holding up a heavy cow is some serious work, work that requires a lot of oxygen for fuel, which is where myoglobin comes in.
支撐一隻沉重的牛是很累人的工作，需要許多氧當燃料的工作，這就是肌紅素發揮功能的地方了。 - 「碰巧、剛好」- Happen To
If you happen to like steak, but you don't want red juice, you have options.
如果你剛好愛吃牛排，但不想要有紅色肉汁的話，你有選擇。
