The logical explanation is the journey our meal takes between the kitchen and the plane. Food is prepared, left to cool and then reheated. But this is certainly not the only influencing factor. Kilometers high in the air, the cabin should be pressurized and heated. The fact that the air is cooler and drier with less pressure affects the sense of smell and taste. As a result, the food on the plane is often as tasteless as it is during a cold. Research in a pressurized cabin has shown that the salinity and sweetness of the meal are sharply reduced, while the sour, bitter and spicy portions are not affected at all.
Stimulating our senses can also affect our taste experience. Scientists have noted that if travelers are disturbed by unpleasant noises, their ability to perceive sweet and salty tastes is impaired. Only flavors that have already experienced flight to great heights. On the other hand, umami can be slightly appreciated. So noise canceling headphones with some salt and sugar might help. Although the latter will not benefit your health much. Then an extra drink to make up for the dry air.