Wild Melons

Citrullus lanatus / Mashamba (Sh) / Amajodo (N)

Bush melons are the biological ancestor of the watermelon, now found all over the world, but which originated in the Kalahari region of Southern Africa.

The fruits differ in shape (from small and round in the wild, to larger and more oblong-shaped under cultivation) and colours. The flesh can be white, yellow, green, orange or red, with a high water content, diverse also in texture and taste. The seeds again vary in seed coat pattern and colour.

Two major forms occur: C. lanatus var. lanatus, the sweet watermelons, and C. lanatus var. citroides, the cow-melons which, although non-bitter, are not sweet. Citrullus lanatus var. citroides is often cultivated but a diversity of feral forms exist. By contrast, C. lanatus var. lanatus is only known from cultivation and has emerged as a result of a domestication process involving selection for reddish colour and sweetness.

BIZ is busy recording the wild melon varieties and landraces available in Zimbabwe, each with distinct local names, morphological characteristics and traditional uses, their main source areas and current volumes, and collecting samples to determine whether their seed oil is commercially usable.

BIZ would like to establish if the fatty acid profiles of the oils that come from different varieties fit within the Kalahari Melon Seed oil specifications. If they do, this implies we can produce KMS oil from varieties currently available in Zimbabwe. If there are differences, perhaps they result in new and different oils of commercial interest.

Overview

Where they can be found: Bush melons are highly adapted to surviving drought and high light stress conditions. They are therefore adapted to desert habitats and found all over Southern Africa, most closely associated with the Kalahari sands of Namibia, Botswana, south-western Zambia and western Zimbabwe.

What is harvested – Harvesting time: Melons grow in summer and have a long growing period though there are some short-season varieties. Fruits are harvested while fresh. The flesh contains numerous oil and protein rich seeds.

Properties

Melon seeds have both nutritional and cosmetic importance.

The seeds contain vitamin C, B2 and G, minerals, riboflavin, fat, carbohydrates and protein.

The oil content of the seeds is high. The oil is cholesterol free, and rich in unsaturated and essential fatty acids. There is a high anti-oxidants activity. These characteristics make the melon seed oil particularly interesting to the cosmetic industry where it is used for moisturising, regenerating and restructuring skin-care formulations.

Use

Cow-melons have a longer shelf life than sweet watermelons and can be stored for more than a year under shade. Traditionally, wild melons have been consumed as a food, a dessert, and for animal feed. The fruit can be eaten fresh; cow-melons are consumed mainly after cooking to produce a meal called nhopi in the Shona or umxhanxa in the Ndebele language, and are also used as livestock feed. They are especially useful for fruit preserves, because of a high pectin content. In some areas, wild melons are used as a source of water during dry seasons.The rind can be pickled or candied.

The seeds are highly prized both as a protein-rich snack food (baked or roasted for consumption), and for their oil content. The seeds are rich in a clear, yellow oil which has a long history of use as a cosmetic. Traditionally used as a moisturiser to protect the skin from the sun, to ensure a blemish-free complexion, to promote hair growth and in soaps. Modern entrepreneurs have developed effective and popular skin lotions and tonics building on this traditional heritage.