Effect of Storage and Heat Treatments on the Sugar Constituents in Cassava and Yambean Roots

Abstract

The effect of storage and heat treatments on the sugar constituents of cassava and yambean roots were investigated using a high performance liquid chromatography (HPLC). Essentially, the total sugar content increased during the first one or two weeks of any 18-28 days storage period. Also, the ratios of fructose and glucose to total sugar content increased, while the ratios of sucrose and inositol decreased. The linamarin content increased markedly in the first 7 days, and continued to increase for several additional days; then it gradually declined and almost disappeared before decay. In yambean root, the three sugars of glucose, fructose and sucrose were found. Although heat treatments by boiling, roasting, and drying all tended to increase the total sugar content of these roots, the linamarin content of cassava roots and of finely-chopped cassava leaves significantly showed a tendency to decrease by such treatments. Investigated at the same time were changes in the constituent pectic substances of these roots. Finally, the changes in appearance occurring in cassave root tissue during storage and heat treatment were observed by a scanning electron microscope (SEM).