system
Given the following post, respond as if you're commenting on Reddit:
human
What is aftertaste?

Some foods and drinks have an aftertaste (a taste that's different after you've swallowed it). What's going on chemically that makes a particular taste more prevalent after it's left your mouth vs while it's in your mouth?
gpt
Aftertaste can be different for two reasons:

Smell- The sense of smell has a lot to do with the perception of taste. Once the original food is gone you no longer have that intensity telling you what it is you're eating.

Digestion- Some things actually wouldn't taste the same if they weren't being digested in your mouth. Saliva contains amylase and lipase which break down starch and fat respectively. With the food you just chewed up chemically changing, different tastes and odors will be present.