Bush tucker has emerged as Australia's secret weapon in the worldwide war on famine and starvation - with the vision of a "great green wall" of wattle trees extending around the globe to arrest the march of deserts and provide a new source of nutrition.
Australian acacias have the potential to be used to provide food and fuel, halt soil erosion, protect other crops and restore fertility to damaged semi-arid regions of Africa and Asia, a national scientific study has found.
Wattle seeds are highly nutritious, have been a staple food for Aboriginal people for thousands of years and are finding ready acceptance as a food crop on the western fringes of the Sahara, according to Dr. Chris Harwood and Dr. Alan House of CSIRO's Division of Forestry.
"We believe there is great potential to use wattle seeds to help alleviate hunger in semi-arid countries, many of which already grow wattles for firewood and as windbreaks," the two researchers argue in a new book, Australian Dry-Zone Acacias for Human Food.
Study of the seeds of 44 acacia species most commonly eaten by Aboriginal people out of 900-plus which grow here - have led researchers to conclude that they are in many ways an ideal and highly nutritious food. Typically, acacia seeds contain 23 per cent protein, 26 per cent carbohydrates, 32 per cent fibre and 9 per cent fats.
"That's a good profile, but of course it varies a lot from species to species. Still it suggests we could pick out the species to meet particular nutritional needs," Dr. Harwood says. The best kinds of wattle compare favourably with other high-protein grains such as peas, lentils, chickpeas and soybeans.
While there is some concern over toxicity, the wattle species used for food tend to be fairly innocuous. One of their main drawbacks, protease inhibitors which interfere with digestion of protein, can be eliminated by cooking, he says.
Seed yields are also heavy - typically 2-4 kilos a tree - offering a potential harvest of a tonne or more of grain a hectare from a close-planted stand of wattles.
An ample supply of high-protein food available at a time of drought when other annual crops fail could spell the difference between life and death, Dr. Harwood suggests.
Wattles are already extensively planted in West and East Africa, parts of the Middle East, India, China and arid parts of South-East Asia, he says.
"They also taste pretty good. They have a rather nice, nutty flavour - not unpleasant at all. But we'd see them being ground to make flour to blend with other kinds of flour," Dr. Harwood says.
"To date, Australian plants haven't contributed much to the world's dinner plate. Despite our rich heritage of native flora, only one - the macadamia nut - is grown widely as a food crop," he says. "There are lots of species with potential."
But across the world, in other dry countries, Dr. Harwood sees Australian species increasingly coming to the rescue of regions facing devastation.
DATE: November 1992
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