Minor cucurbits from Africa: Horned melon (Cucumis metuliferus E. Mey. Ex Naudin)

Horned melon (Cucumis metuliferus E. Mey. Ex Naudin) (2n = 24) belongs to the family Cucurbitaceae and genus Cucumis. Horned melon is known by many names such as jelly melon (English), métulon (French), Kiwano® (in New Zealand), Melano® (in Israel), bitter wild cucumber (in South Africa), thorn melon (in Kenya), parachichi mwitu (Kiswahili in Kenya), African horned cucumber, orange spiky fruit, among others. Other members of the genus Cucumis are cucumber (Cucumis sativus) and melon (Cucumis melo). This review aims to present horned melon as a minor cucurbit that originated from Africa; its production, nutritive and nutraceutical values have been expounded. Horned melon originated from central and southern African region from where it spread to other regions as far north as Senegal, Nigeria, Ethiopia and Somalia. Horned melon is native to the dry Kalahari desert and it mostly grows in the dry or semi-arid places of the world. In many African countries, horned melon has generally been neglected by scientists as well as policy makers. It has been minimally exploited economically despite its high nutritive and medicinal value. The fruit has been introduced and is currently grown in other countries and continents. In Kenya, New Zealand, France, Australia, USA, and Israel, fruits of improved cultivars are commercially grown for export. Horned melon features in the international trade due to its high nutritional fruit value and as an ornament due to its interesting appearance and long shelf life. Horned melon fruit is more nutritious than cucumber. Its concentration of vitamins B complex, A and C is four times higher than in lemon. It is rich in antioxidants such as vitamin C, vitamin A, zinc, and lutein while the seeds are rich in antioxidants alpha-tocopherol and beta-tocopherol, both of which are organic forms of Vitamin E. The fruit also possess high mineral content particularly potassium, phosphorus, magnesium, calcium, iron, sodium, zinc, and copper. Consequently, it lowers the onset of heart diseases, high blood pressure, dementia and Alzheimer’s disease, and promotes good eyesight, as well as healthy and strong bones, among others. Despite all the goodness of this fruit, it is rarely consumed especially by the urban population probably due to its unfavourable taste or lack of awareness of its nutritive value. The fruit should be promoted given that lifestyle diseases are a real menace especially among the urban population. In addition, breeding efforts should be enhanced to develop horned melon varieties that are more palatable.