REDUCTION OF CYANOGEN LEVELS DURING SUN-DRYING OF CASSAVA IN TANZANIA

Sun-drying of cassava roots is known to be an ineffective processing method as it yields products with relatively high residual levels of cyanogenic glucosides.
Studies in Tanzania have shown that sun-drying whole roots into makopa, a product which is usually milled or pounded into flour, reduces glucoside levels from 751 to 254 mg HCN equivalent kg^-1 (dry weight basis). Cyanohydrin and hydrogen cyanide (HCN) levels were negligible in the flour, which retained 11% moisture.
In a short-cut, sun-dried product called chinyanya, which can be obtained within one day after alternate pounding and sun-drying of fresh roots, the glucoside levels were reduced from 822 to 97 mg HCN equivalent kg^-1 (dry weight basis). However, the mean residual level of cyanohydrin was 39 mg HCN equivalent kg^-1 (dry weight basis) in the final chinyanya flours which had a moisture range of 10–19%. These findings confirm that direct sun-drying of cassava roots is an ineffective method for removal of cyanogens.

International Workshop on Cassava Safety

N. L.V. Mlingi, Z. Bainbridge

Cassava processing, moisture levels, cyanogen removal

https://doi.org/10.17660/ActaHortic.1994.375.23