为什么茶凉了味道会不一样?

Chris -问得好。我认为可能有三到四个原因。最主要的原因是温度。当你把食物和饮料放进嘴里的时候，我们所说的味觉可以归结为嗅觉。你可以自己证明。如果你把味道很重的东西放进嘴里，然后捂住鼻子，你会注意到它似乎失去了大部分的味道。这是因为当你把热的或冷的东西放进嘴里时，你嘴里的热量就会挥发，换句话说，食物中的一些挥发性化学物质会变成蒸汽。然后它们漂浮在你的鼻子后部进入你的鼻咽部，在那里它们与你的嗅觉上皮中的化学受体对接。这就是你闻到的味道。这会告诉大脑有特定的味道。 Most of the food we eat we actually experience the taste as a smell. When you put cold tea into your mouth the temperature means that many of the volatile chemicals that are in the tea don't escape the tea in the same way or at the same rate that they would do with hot tea. The more energy that these chemicals are given the more of them will be driven off. This means that as a result less stimulation goes into the olfactory epithelium so the taste is less strong for some chemicals than others. The tea tastes different. The second point is that when tea's cold the viscosity is very different. It's a thicker fluid than when it's hotter. This means that the stimulation into your mouth and tongue is a bit different. So it tastes and feels different in the mouth which also changes your perception of the flavour of the tea. Then there's another possibility and that's when tea has stood for a long time and gets cold it has separated out according to density of the different components of the tea. If you have got a hot cup of tea you have thermal activity in the fluid so hot things are rising to the top and cold fluid is going to the bottom. This keeps the contents mixed. When you have a tea cup standing there for a long time and the temperature's fallen then it stops mixing like this and things get separated out. The fatty, less dense things go to the top and the more dense things go to the bottom. The mouthful of tea you get isn't a mixture of tea like it would have been before when it was hot.