Temperature’s role in how we perceive our foods’ flavors
Many foods taste delicious piping hot, but then lose their luster as they cool. This may be a texture issue (looking at you, McDonald’s french fries) but new research has found that we may taste specific flavors differently when they’re hot or cold. In addition to explaining why cold broccoli may taste more bitter than cooked broccoli, researchers also found a strange clue about this all stemming from our own sensory abilities rather than changes in the food itself.
The core of this research had participants rate the intensity of flavored liquids a different temperatures. This way shifts in texture would be eliminated, as texture can be an overwhelming factor in experiencing food for some people. It also helped avoid other sensory inputs, like sights or smells, which commonly help shape our impression of a flavor. Instead, the variables were reduced to flavors and temperatures of either 41° or 95 °Fahrenheit.
The only flavor be intensified at lower temperatures was bitterness, as in the aforementioned broccoli example. On the other end of the scale, sour and astringent flavors were stronger in warm liquid. The oddball flavor was everyone’s favorite: sweetness. While it took longer to sense sweetness when it was cold, it eventually was noted as tasting just as strongly in either solution. Perhaps our species’ evolutionary history so strongly prioritized finding sources of sugar that our tongues are sure to note sweetness at every opportunity?
All the taste without the (ingested) calories
Since cooking food does change its chemistry, it’d be easy to assume that the warmer liquids simply interact differently with our tongues than the cold liquids. However, researchers also found a group of people, possibly between 20 – 30% of the population, that are ‘thermal tasters.’ Thermal tasters can have flavor responses triggered simply by warming or cooling regions of their tongue, with no food present. This indicates that our perception of flavor may have more ties to our own physiology than just being a passive receptor of flavors from food.
Source: 'Thermal tasters' can experience taste from heating or cooling tongue without any food by Spring Science + Business Media, Science Daily