Posted by: Glow-worm PJ18 DEC 2013
The moringa tree, Moringa oleifera, is a drought-resistant native of the Himalayas, although it is grown in many other tropical and subtropical areas. Most parts of the plant are eaten, and they are an excellent source of many vitamins, minerals and amino acids. The fresh leaves contain almost 10 per cent protein and are also a valuable source of vitamins A, B and C, as well as iron, copper and manganese. The pods and seeds contain high levels of the mono-unsaturate oleic acid.
These nutritional benefits, as well as a relative ease of cultivation and speedy growth, have resulted in the plant being advocated by welfare bodies as a “natural nutrition for the tropics”, with the recommendation that powdered leaf powder be used in situations where there is risk of starvation.
Moringa seeds have a long tradition of use in the clearing of turbid water. Since the 1970s instructions for their domestic use have been issued in areas with poor-quality drinking water. The seed kernels contain significant quantities of low-molecular weight, water-soluble proteins that, when crushed and agitated, act like synthetic polymer coagulants, binding to particles in the water, such as silt, bacteria and clay, which then flocculate and can be removed by straining or sedimentation.
Recent research, published in the journal Colloids and Surfaces, used neutron scattering techniques to examine the microscopic formation and structure of flocs produced by protein extracts of seeds from different varieties of moringa tree. The researchers found that the flocs were more tightly formed than when conventional commercial flocculating agents were used, allowing easier separation and water purification.
Several African governments have shown an interest, and it is hoped that the use of regulated seed extracts, rather than simply crushed seeds, will lead to a cheap, sustainable alternative to the conventional materials currently used in large-scale water purification plants.