On Food and Cooking

mature but still green, and will ripen well on
their own, especially if nudged by an artificial
dose of ethylene. They often store their sugars
in the form of starch, which enzymes convert
back into sweetness during the post-harvest
ripening.
The other style of ripening is undramatic.
“Nonclimacteric” fruits don’t respond to
ethylene with their own escalating ethylene
production. They ripen gradually, usually
don’t store sugars as starch, and so depend on
their connection to the parent plant for
continued sweetening. Once harvested, they
get no sweeter, though other enzyme actions
may continue to soften cell walls and generate
aroma molecules.
These basic styles of ripening determine
how fruits are handled in commerce and in the
kitchen. Climacteric fruits like bananas and
avocados, pears and tomatoes can be picked
mature but still hard to minimize physical
damage, packed and shipped to their