Montreal Gazette - Gases are key to how fruits, veggies ripen

Chemistry professor Joe Schwarcz: It's alive! The banana's alive. So is the broccoli and the asparagus and the melon. A new horror movie? No. But real-life horror for fruit and vegetable marketers.

Such produce contains living cells that continue to "respire" even after picking. Just like us, they inhale oxygen and exhale carbon dioxide and water. During respiration, which is exactly the opposite of photosynthesis, oxygen reacts with stored glucose, and provides the energy needed to fuel the reactions we interpret as "ripening."