The ripening of fruits is hastened by using ethene. Ethene is a plant hormone that regulates the process of ripening in fruits. It is produced naturally by plants, including fruits, and can also be produced synthetically. When ethene gas is introduced to a fruit, it triggers a series of biochemical reactions that lead to the ripening of the fruit. The gas promotes the breakdown of chlorophyll, which gives fruits their green color, and the conversion of starches into sugars. This process makes the fruit softer and sweeter, and also stimulates the production of more ethene gas, which in turn hastens the ripening of the fruit.