All fruits and vegetables give off Ethyleneethylene is, a harmless, natural plant hormone that can be used to ripen fruitstimulates ripening. BananasRipe bananas give off a smallrelatively large amount of etyhlene, so placing other fruits in a confined space (a paper bag works great) together with some ripe bananas or banana peels will speed up the ripening of the other fruits.
I know from experienceSome examples of fruits that it works for ripening applesproduce relatively much ethylene are: apples, apricots, avocados, ripe bananas, cantaloupe, kiwifruit, mangos, melons, nectarines, papayas, peaches, pears, plums and other bananastomatoes. I'm not sure if If you bruise a fruit or vegetable it generally will work withproduce more ethylene.
Note that not all fruit typesfruits and vegetables are equally sensitive to ethylene.