ABSTRACT

The effects of Solar, Oven, Sun and Tray drying methods on the cyanogenic content of Pro-Vitamin A Cassava cultivars (UMUCASS 36 and UMUCASS 37) was investigated using spectrophotometric method. The toxicity of this Pro-Vitamin A High Quality Cassava Flour (HQCF) was also studied in male albino wistar rats fed for 28days on the Cassava diet containing 4.794 mgCN^-kg^-1 and 10% protein supplement. The total cyanide concentrations of the fresh (unprocessed) samples were 97.812 mgCN^-kg^-1 and 102.564 mgCN^-kg^-1 and those of the dewatered samples were 11.088 mgCN^-kg^-1 and 17.028 mgCN^-kg^-1 for the Pro-Vitamin A Cassava cultivar UMUCASS 36 and UMUCASS 37 respectively. The total cyanide concentration of dried Pro-Vitamin A HQCF (UMUCASS 36) were 2.772 mgCN^-kg^-1, 2.544 mgCN^-kg^-1, 7.920 mgCN^-kg^-1 and 5.940 mgCN^-kg^-1 for Solar, Oven, Sun and Tray dried samples respectively. Moreover, The total cyanide concentration of dried Pro-Vitamin A HQCF (UMUCASS 37) were 7.920 mgCN^-kg^-1, 3.168 mgCN^-kg^-1, 7.128 mgCN^-kg^-1 and 3.376 mgCN^-kg^-1 for Solar, Oven, Sun and Tray dried samples respectively. Analysis of serum and urinary cyanide and thiocyanate concentrations of the test groups showed statistically significant increase (p < 0.05) when compared with the control group. There was increase in the serum glucose concentration, serum activity of Aspartate Aminotransferase and Alanine Aminotransferase of the test groups compared with the control group. The serum total protein concentration showed significant decrease (p < 0.05) between the test and control groups. The haematological studies showed no significant difference (p < 0.05) between the test and control groups. The results showed that the Pro-Vitamin A Cassava cultivar (UMUCASS 36 and UMUCASS 37) have low cyanide content. Results also showed that Oven dried method, which reduced cyanogenic content by 97.4% and 96.9% for UMUCASS 36 and 37 respectively, is the most potent drying method, out of the four (4) drying methods investigated. Toxicity study suggested that the in vivo metabolism of Pro-Vitamin A HQCF was capable of altering some biochemical parameters such as elevation of serum glucose concentration and some enzymes such as aspartate aminotransferase and alanine aminotransferase, whereas a reduction in serum total protein concentration was observed. The nutritional and toxicological implications of these findings are discussed.