Ethylene is a hydrocarbon gas which is thought as the ageing hormone in plants. It also causes ripening in fruits so known as the ripening hormone. As the fruit ripens many changes occurs; the unripen fruits are usually green, sour, odorless and hard. The process of ripening makes the fruits appealing, sweet the colour also changes as the chlorophyll is broken down and sometimes new pigments are also formed. The acids that make the fruits sour are also broken down, the mealy starch are converted into sugar, hard nature get softened and sweet aroma are formed. So that the fruits after ripening becomes soft, juicy, sweet, fragrant and also colorful too. Certain fruits itself produces the ethylene hormone this ethylene hormone triggers the genes that in turns make the enzymes that causes the ripening.