By Joshua Kato
IT was supposed to be a relieving lunch, especially after two days of starvation. However, even before cooking the prized cassava that the family had gathered from the garden, they started dying. Each of them had chewed a small piece of the raw cassava. It turned out that the cassava was poisonous.
So far, eight people have died after eating poisonous cassava during the current famine ravaging Acholi, Teso and Lango regions. According to Dr. Titus Alicai, a plant pathologist working with the National Crops Resources Research Institute, all cassava is potentially poisonous. Cassava does not contain common poisons, but the highly fatal cyanide. The same element is also traced in sorghum and millet, although in less quantities.
In almost all cases, the cyanide element remains in stable form, thus not dangerous to humans. However, if the cassava is mishandled during the harvest, there is a minimal likelihood that it may react dangerously.
â€œThe plant has an enzyme that breaks it up to release the poison, however, if it is damaged during harvest, for example, this enzyme may not break it up,â€ Alicai says.
Alicai explains the species being released by the National Agricultural Research Organisation are the sweet type of cassava that people can even eat raw.
â€œThese are low on cyanide and are harmless,â€ he says. The compound is more active in the bitter varieties.
â€œMost of these are local breeds. Farmers like them because they are not attacked by animals,â€ he says.
However, if these varieties are eaten raw, there is a likelihood that a person may be affected by cyanide.
Communities in Teso, Acholi and Lango that plant these varieties know how to process them to release the cyanide.
â€œThey ferment them in water, dry them and turn them into flour. By the end of the process, the fatal compound has already evaporated.
When the bitter cassava is peeled and washed, the cyanide drops to around 40%. When it is cut into pieces, it reduces by around 35%, fermenting for at least five days lowers it to 15%, while roasting or drying pushes it to 3%, which is not dangerous for human consumption.
â€œNot all bitterness in cassava is caused by cyanide. Bad weather, rocky soils and poor handling after harvest also contributes to the problem,â€ he says.
For bad weather, the cassava turns bitter if the plant is attacked by hailstorms. However, Alicai says some of the people who were poisoned did not eat real cassava, but its wild relative. â€œWe followed up one of the cases and discovered that these people ate roots of a wild tree that resembles cassava.â€