The Work of Ethylene and Enzymes

The final stage of fruit development is ripening, a drastic change in the life of the fruit that leads to its death. It consists of several simultaneous events. Starch and acid levels decrease, and sugars increase. The texture softens; defensive compounds disappear. A characteristic aroma develops. Skin color changes, usually from green to a shade of yellow or red. The fruit thus becomes sweeter, softer, and tastier, and it advertises these improvements visually. Because ripening soon gives way to rotting, ripening was long considered to be an early stage in the fruit’s general disintegration. But it’s now clear that ripening is a last, intense phase of life. As it ripens, the fruit actively prepares for its end, organizing itself into a feast for our eye and palate.