Food might not be all that common on airlines anymore, but one particular beverage seems to be particularly popular for frequent flyers.

Look around the next time you're on a plane and you might see an inordinate volume of tomato juice being sipped. Back in 2008, the folks at German airline Lufthansa noticed they were going through a lot of tomato juice. At the time, the airline was serving 1.7 million litres a year to passengers.

Interestingly, many of those tomato juice drinkers admitted that they never bought the stuff at home. The observation led to research being done in Germany that suggests flyers tend to like punchy flavours in low-pressure environments.

Robin Dando, a food scientist at Cornell University in Ithaca, N.Y., has written a report, published in the Journal of Experimental Psychology: Human Perception and Performance, that looks at the loud noise of airplanes, and the effect it has on our tastebuds.

"There aren't very many situations where we tolerate something quite as loud as an airplane," he said. "It's very, very loud. There aren't many situations where we experience that. But it also happens to be a situation where people complain about the quality of the food on airlines, we thought this would be an interesting model."

Dando invited study subjects into his lab on two separate occasions. On one of those visits, they listened to recordings of airplane noise through headphones and after some baseline tasks, questions and time to settle in, they were given various foods.

Dando found that under noisy conditions, there wasn't much effect on salty, sour or bitter tastes. Sweet tastes, however, were inhibited. While one taste, umami, was actually enhanced — in some cases by 20 per cent.

'Packed with umami flavour'

Umami is a Japanese term that describes that rich, savoury flavour found in things like grilled meat, roasted nuts, sauteed mushrooms, cheese, soy sauce and tomato juice.
Dando wasn't expecting it, but his study suggests that umami-rich foods such as tomato juice just taste better in the air.

"All the other drinks would be very high in sweetness, cans of soda, fruit juices, which of course would be inhibited by the loud noise conditions. But tomatoes are absolutely packed with umami flavour, which is part of the reason we like them so much. So it might be that the glass of tomato juice you have on a plane might be the best tasting glass of tomato juice you ever have," he said.

The popularity of tomato juice on an airplane is not necessarily tied to Dando's noise theory. It might have something to do with a learned cultural behaviour — just as we've come to crave popcorn at the movies, we've come to crave tomato juice on planes.

It might have to do with the fact that it's verbally offered to us, or maybe we just notice the person next to us drinking tomato juice and we want some too. But all in all, Dando said once we do taste something rich in umami on a plane, it tastes particularly good. And we keep coming back to it.

"I'm not actually a tomato juice drinker, I'm not keen on it myself," he said. "But this is making me think maybe I should try it next time. I've only ever had it on the ground, so maybe that's what I need to do."