On 21 May 2006 12:43:16 -0700, "Radium"
wrote:

I am interested in what chemicals are responsible for the foul odors
emitted by ripe fruits.

I find the smell of most ripe fruits to be pleasant.

If you mean overripe fruits then you are smelling the waste
products of the microorganisms that are breaking down the fruit.
The gas likely depends on which putrefying bacteria are prevalent
in your area.