Ethylene is effective at ripening fruits at a parts-per-billion level.
It only begins to smell sweet at concentrations above 500
parts-per-million. much higher than would be found in a ripening fruit.

"An ethylene by any other name would smell as sweet!"

John
Aspen Research, - www.aspenresearch.com
"Turning Questions into Answers"

Opinions expressed herein are my own and may not represent those of my
employer.