Melon

Cucumis melo, also known as melon or true melon, is a species of Cucumis that has been developed into many cultivated varieties. The flesh is either sweet or bland, with or without an aroma. Melons were domesticated four times independently. Some botanists consider melons native to the Levant and Egypt, while others place the origin in Persia, India or Central Asia.

Origin and Production

Melon is a fruit in the cucurbitaceous family, like zucchini, squash, pumpkin and cucumber. Iran, India, Uzbekistan, Afghanistan and China became centers for melon production. In 2018, world production of melons was 27 million tonnes, led by China with 46% of the total.

Uses of the Fruit

In addition to being eaten fresh, melons are sometimes dried. Some varieties are grown for their seeds, which are processed to produce melon oil. The oil obtained from the seeds is used in cosmetics. Still other varieties are grown only for their pleasant fragrance. A Japanese liqueur is flavored with melon.

Chemistry

Esters, alcohols and aldehydes are the most abundant volatile compounds in melon. Some key volatile compounds identified in melon are nonanal, 6-nonenal (Z) and 2,6-nonadienal-(E,Z). In melon, most esters contribute fruity and sweet notes, while aldehydes and alcohols contribute green, fresh, cucumber-like ones. The compounds 6-nonenal (Z) and nonanal give melon-like and citrus notes. Together, 2,6-nonadienal and 6-nonenal (Z) give honeydew and cucumber notes. Esters such as hexyl acetate and ethyl acetate are highly abundant in climacteric melons. Calone, a white solid, is known in the fragrance industry as watermelon ketone.

Properties of cis-6-Nonenal

cis-6-Nonenal has a molecular weight of 140.22. It is a colourless to pale yellow liquid. Its boiling point is 87.00 °C at 19.00 mm Hg. It is soluble in alcohol and essential oils and insoluble in water.