It's not a common juice, like orange or apple.

這不是如柳橙汁或蘋果汁這樣常見的果汁。

So why are so many people drinking it in flight?

那為什麼這麼多人在飛機上喝番茄汁呢？

Put simply?

簡單來說嗎？

Your taste changes while you're in the air.

因為你的味覺在空中改變了。

And there's a biological reason for that.

而這可以從生物的角度去解釋。

If you grab a bite before your flight, you probably have an idea of what it will taste like.

如果你在登機之前有吃點東西，你大概知道這個東西嚐起來應該是怎樣。

But once you're in the air, your sense of taste isn't the same as it is on the ground.

但一旦到空中，你的味覺就跟在地面上時不一樣了。

A lot of factors on the plane are all coming together to suppress your sense of smell, which makes up a large portion of our sense of taste.

飛機上有很多因素箝制了你的嗅覺，而嗅覺佔了很大一部分味覺。

Think back to the last time you had a cold.

回想上次你感冒的時候。

Remember how you couldn't taste anything because your nose was clogged up?

還記得因為你鼻子都塞住了所以吃不出任何味道嗎？

When you have a weakened sense of smell, your perception of taste is reduced.

當你的嗅覺減弱，你對味覺的認知也會因此變弱。

So your in-flight nose is similar to your nose when you have a cold, but hopefully with less phlegm.

所以搭乘飛機的鼻子與你感冒時的鼻子狀態類似，但好在痰比較少。

Let's start with the cabin, which is extremely dry.

那先讓我們談談超級乾燥的機艙。

Drier-than-some-deserts dry.

是比沙漠更沙漠的乾。

The dry cabin dries out your nasal passages, which means your taste buds become less perceptive.

乾燥的機艙使你的鼻腔乾燥，意味著你的味蕾也變遲鈍。

But that's not the only part of the cabin suppressing your sense of taste.

但這不是機艙內唯一會箝制你味覺的因素。

The low cabin pressure actually decreases the levels of oxygen in your blood, which means your olfactory receptors, the part of your nervous system that responds to smells, become less sensitive, which actually weakens your sense of smell.

機艙內的低氣壓會降低血液中的氧含量，意味著你的嗅覺受器，你神經系統中反饋味覺的部分，會變得遲鈍，而這也使你的嗅覺變得遲緩。

But it's not just the environment inside the cabin that's affecting your senses.

但不只是機艙內的環境影響了你的感官。

The noise coming from the engine isn't helping either.

引擎的噪音也是原因之一。

A 2010 study tested people's sense of taste both inside and outside a simulated plane cabin.

一個 2010 年的研究測試了在模擬機艙內與機艙外的人的味覺。

The researchers found sensitivity to sweet and salty food was reduced by 30 percent while in the cabin.

研究人員發現，機艙內的人味覺對於甜和鹹的食物敏感度減少了百分之三十。

And that weakened sense of taste can cause a lot of problems for airline caterers, who have to modify every recipe to account for it.

這變弱的味覺會為航空餐飲業者帶來很多麻煩，因為他們需要根據這個狀態修改食譜。

To top it off, not every flavor is affected equally.

除此之外，每種味道被影響的程度不同。

Some ingredients, like curry and lemongrass, actually become more intense in the sky, while cinnamon, ginger, and garlic tend to maintain their taste.

有些原料，例如咖哩和檸檬草，在空中其實變得更強烈，而肉桂、薑和大蒜則是持平。

Some airlines will use naturally intense flavors, like certain fruit and vegetable oils and concentrates, which helps to lessen the amount of extra salt a recipe might need.

某些航空業者會使用天然就強烈的味道，例如某些特定水果、植物油或濃縮汁，這幫助減少原本菜單可能要額外加的鹽量。

So, what does tomato juice have to do with all of this?

所以，番茄汁到底跟這一切有什麼關係呢？

Well, tomato juice tends to have a savory flavor referred to as umami.

番茄汁往往都有一種鹹味，而這個鹹味稱之為「鮮味」。

It's one of the five categories of taste, along with sweet, sour, salt, and bitter.

它是五種味覺中的其中一種，其他四種為甜、酸、鹹和苦。

A 2015 study found that, with umami, the taste phenomenon is actually reversed.

一個 2015 年的研究發現，鮮味在味覺上的改變是相反的。

Umami is actually enhanced in the air.

鮮味在空中通常會變強烈。

So the next time you're on a flight, give the tomato juice a try.

所以下次如果你搭飛機，可以試試喝番茄汁。

And don't get too upset if your meal doesn't taste as good as you hoped.

還有，如果你的飛機餐沒有預期中的好吃，不要覺得失望。

The chefs are just trying to accommodate for something you didn't know was happening right underneath your nose.

廚師們已經試著去配合那些你所不知道的、發生在鼻子裡的事了。