Chemical safety of cassava products in regions adopting cassava production and processing--experience from Southern Africa

Abstract

The cassava belt area in Southern Africa is experiencing an unforeseen surge in cassava production, processing and consumption. Little documentation exists on the effects of this surge on processing procedures, the prevailing levels of cyanogenic glucosides of products consumed and the levels of products commercially available on the market. Risk assessments disclose that effects harmful to the developing central nervous system (CNS) may be observed at a lower exposure than previously anticipated. We interviewed farmers in Zambia and Malawi about their cultivars, processing procedures and perceptions concerning cassava and chemical food safety. Chips, mixed biscuits and flour, procured from households and markets in three regions of Zambia (Luapula-North, Western and Southern) as well as products from the Northern, Central and Southern regions of Malawi, were analyzed for total cyanogenic potential (CNp). Processed products from Luapula showed a low CNp, <10 mg HCN equiv./kg air dried weight, while samples from Mongu, Western Province, exhibited high levels of CNp, varying from 50 to 290 mg HCN equiv./kg. Even the lowest level is five times higher than the recommended safety level of 10mg/kg decided on for cassava flour. Our results call for concerted efforts in promoting gender oriented processing technologies.