Antinutritional Factors Reduction from Cassava (Manihot esculenta Crantz) Roots by Grating or Chipping Processing Technique in Mtwara Tanzania

Regular intake of diets high in cyanogenic amount in iodine deficiency areas with limited sulfur supply diets have been associated with the development of hypothyroidism, goiter and cretinism in young and adult populations. This study aimed at the investigation of the suitable processing technique for the production of high-quality cassava flour (HQCF) with acceptable consumption level of cyanide residues from different cassava varieties available at Mmongo village in Mtwara region. Grating technique was used to produce wet and dried cassava grits, whereas chipping technique produced wet and dried cassava chips. The wet and dried cassava products were all produced in a single day and under the same environmental conditions. The results showed that the hydrogen cyanide (HCN) in fresh cassava roots was 62.18–139.28 mg HCN/kg. Upon processing, the cyanide was lower (P<0.05) in wet cassava grits 24.27–76.74 mg HCN/Kg but higher in wet cassava chips 44.81–92.57 mg HCN/kg. After sun drying, the HCN retention was higher in dried cassava chips (10.7–14.2%) and lower in dried cassava grits (7.3–9.1%). Grating, efficiently reduced HCN from bitter cassava roots to the level within the WHO/FAO recommended safe limit (10 mg HCN/kg) as chipping only suite for sweet cassava roots. Therefore, HQCF can be nutritionally strategic cassava product consumed regularly and during food shortage without causing potential health problems even in iodine deficiency areas.