Moringa, widely grown in Kerala and Tamil Nadu, have excellent ability as natural water purifier. The seeds of drumstick have also oil content which can be extracted on a commercial basis, says Geoffrey Keith Folkard, a faculty member of the university.

According to him, research in the Leicester University led by the environmental engineering group of the university, over the last 12 years has succeeded in identifying these properties and field trials in some African countries have already established the commercial potential.

However, Folkard ruled out the possibility of he or his team patenting the knowhow. "I am not a man of economics or commerce to go for patenting," said Folkard who is on a private visit to the State.

He said drumstick seeds contain 40 per cent oilwhich could be extracted in a commercial manner. The dried drumsticks and the presscakes after oil extraction could also be used a natural water purifier.

Folkard said more than 250 papers giving the various possibilities of value-addition from drumsticks have now become available.

"Crushed seeds of the tree are a viable replacement coagulant for proprietary chemicals such as aluminim sulphate (alum) in developing countries," he said.

The pilot and full scale trials in Malawai have demonstrated the effectiveness of moringa seed coagulant for the clarification of highly turbid river water. Inlet turbidities of 270-380 were consistently reduced to below 4 NTU in the finished water," he said.

The seed contains 40 per cent oil. After oil extraction, the presscake contains the active constituents effecting coagulation. Confirmation of the high market value of the oil made the economic case for adoption of presscake as coagulant overwhelming, he said. The golden coloured oil could be used for edible andcosmetic purposes, he added.

The growth of the trees by smallholder farmers should be promoted. This crop diversification strategy should provide both vegetable and raw material for oil extraction. According to Folkkard, "Simple and proven technology is available to allow small scale oil milling enterprises to be established in rural areas with many benefits accruing."

A native tree of India Moringa was now widely cultivated in Africa, Asia and South America, he said. According to Folkard, the some section of people in Africa use the leaves for cooking. But nobody uses the sticks.

Moringa grows rapidly from seed and cuttings even in marginal soil. It needs little or no horticultural attention and possesses a hardiness that enables it to survive prolonged periods of drought, he said.