Team:UNITN-Trento/Extra/Fruit Info

Plants naturally produce ethylene starting from a common amino acid: methionine (MET), which is transformed in S-adenosyl-methionine (SAM) by a reaction catalyzed by SAM synthetase. The key enzyme of the pathway, ACC synthase, converts SAM to 1-aminocycloprane-1-carboxylic acid (ACC), the immediate precursor of ethylene. Quite recently, the final enzyme of the pathway was identified: ACC oxidase, which converts ACC to ethylene.

All fruits, with a few exceptions (European pears, avocados and bananas), reach their best eating quality when allowed to ripen on the tree or plant. However, some fruits are usually picked mature but unripe so that they can withstand the post-harvest handling system when shipped long-distance. Bananas, for example, are treated with 10-100 ppm of ethylene to initiate their ripening during transport or at destination handling facilities. Treatment of avocados, kiwi fruit, mangos and pears before marketing is increasingly being performed to provide consumers with the choiche of purchasing ready-to-eat, ripe fruits or mature fruits that can be ripened at home. This practice has, in many cases, resulted in increased sales and profits.