We now know that when some fruits (like a banana or tomato) ripen, they give off high levels of ethylene gas. The ethylene prompts the fruits to change color, become softer and sweeter, and have a stronger aroma.
If we have unripened fruits such as an unripe tomato, we can put them together with a banana. The ethylene from the banana will speed up the ripening process of the other fruits.
This video below shows how a banana can turn a green and unripe tomato ripe and red in just a matter of days.
Neat, isn't it?
photo: patronestaff/depositphotos