Stansted has worked with a food scientist and luxury cafe to create a sandwich with flavours that are enhanced at altitude.

Airline passengers perceive fewer flavours when flying, so the taste of the new sandwiches will be boosted by adding ingredients rich in umami – the fifth taste after sweet, sour, salty and bitter.

The airport said many airlines no longer serve free food, so passengers often buy their snacks before their flights.

Working with Stansted café Not Always Caviar and Professor Barry C. Smith – director of the Centre of the Study of the Senses at the University of London – the airport developed the Sky High Sandwich to offer passengers the types of flavours used by airlines for business class passengers.

Professor Smith (pictured) said: “Science shows that the combination of dry air and low-pressure during flights reduces our sensitivity to food aromas. Additionally, the sound of white noise at 80 decibels or above has an impact on the brain’s ability to perceive sweet, salt and sour from the tongue – reducing its intensity by about 10-15%.

“Foods rich in umami provide depth of flavour and boost other basic tastes.”

Aboudy Nasser, chief commercial officer at Stansted, added: “The Sky High Sandwich is part of our mission to innovate, by harnessing science to create something unique for our guests that tastes great on the ground and even better up in the air.”

Ingredients in the seafood sandwiches include smoked salmon, shrimp and avocado with lemon and chilli flakes, beef tomato and spinach leaves.

The salt beef deli sandwich contains salt beef, mayonnaise, mustard, cheese, gherkins and spinach leaves.

Both sandwiches include a special umami blend spice which is added as a powder to give it an umami boost.

The Signature Seafood Club costs £9.95, while the Salt Beef Deli is £8.50.