An aroma compound, also known as odorant, aroma, fragrance, flavor, is a
chemical compound that has a smell or
odor. A chemical compound has a smell or
odor when two conditions are met: the compound needs to be volatile, so it can be transported to the
olfactory system in the upper part of the nose, and it needs to be in a sufficiently high concentration to be able to interact with one or more of the
olfactory receptors.
See more at Wikipedia.org...