used glucose syrup from cassava starch, having 97.6% glucose and 2.4% maltose (dwb) for isomerization and found that the isomerized syrup had 36.9% fructose, 60.7% glucose and 2.4% maltose. The fructose yield is dependent on the glucose content in the syrup prior to isomerization and this in turn was dependent on the initial starch content in cassava and sweet potato. As the latter root had much less starch content than cassava, the glucose and fructose yield were also significantly lower than that from cassava (Table 4). Nevertheless, the percentage conversion to fructose was independent of the glucose content in the hydrolysate used for isomerization and almost similar percentage conversion was observed for cassava and sweet potato.