I want to know that how I can ripen fruit as fast as possible. Fruit sellers are using chemicals to do that which is harmful. I would like to know if there are any safe chemicals or other techniques that can hasten the ripening of fruit sustainably.
All fruits and vegetables give off ethylene, a harmless, natural plant hormone that stimulates ripening. Ripe bananas give off a relatively 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.
Some examples of fruits that produce relatively much ethylene are: apples, apricots, avocados, ripe bananas, cantaloupe, kiwifruit, mangos, melons, nectarines, papayas, peaches, pears, plums and tomatoes. If you bruise a fruit or vegetable it generally will produce more ethylene.
Note that not all fruits and vegetables are equally sensitive to ethylene.