The colour betrays the poison
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CTA. 2000. The colour betrays the poison. Spore 88. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/46856
Internet URL: http://spore.cta.int/images/stories/pdf/old/spore88.pdf
Over 2500 plants punish their predators by producing poison when they are eaten by catalysing cyanogenic glycosides. The best known is cassava. Analysing and determining the levels of toxicity in plants is often constrained by a lack of required...
Over 2500 plants punish their predators by producing poison when they are eaten by catalysing cyanogenic glycosides. The best known is cassava. Analysing and determining the levels of toxicity in plants is often constrained by a lack of required chemicals, equipment, money or expertise. Together with colleagues, Howard Bradbury from the Australian National University has developed a range of practical kits that can be used by an unskilled person for looking at cyanide levels in cassava roots and products, as well as other cyanogenic plant parts such as sorghum leaves, bamboo shoots and flax seed meal. The general principle is that a small sample of the plant or product is placed in a container with filter paper containing the required catalyst and a piece of picrate paper that reveals the amount of poison produced. The bottle is left overnight at room temperature. Next morning, when the breakdown to poisonous gas is completed, the colour of the picrate paper indicates the level of toxicity. The researchers have also developed a similar kit for determining the amount of cyanide ingested after consuming cassava or other cyanogenic plants. Ingested cyanide is converted in the body to thiocyanate, which is excreted in the urine. The kits are available free of charge to health workers and agriculturalists in developing countries, through funding from the Australian Centre for International Agricultural Research (ACIAR). J H Bradbury Division of Botany & Zoology Australian National University Canberra ACT 0200 Australia Fax: +61 2 6249 0775 Email: firstname.lastname@example.org