Enzymatic Hydrolysis of Starch from Jacatupé ( Pachyrhizus erosus L. Urban) by Thermostable Amylolytic Enzymes

An alternative source of starch obtained from jacatupé ( Pachyrhizus erosus L. Urban) a tropical tuber has been characterized enzymatically using amylolytic enzymes. The best hydrolysis conditions were obtained using α‐amylase of 13.56U/ml at pH 7.0 and 80°C; amyloglucosidase of 177.5U/ml at a pH range from 3.5 to 4.0 and 70°C, respectively. Michaelis constants were determined in terms of substrate concentration; Km and Vmax for α‐amylase and amyloglucosidase were found to be 16.8g/1, 1.49g/1, 11.2μmol/h and 3.10μmol/h, respectively. Scanning electron microscopy studies suggest that the enzymes tunnelled into the granular interior of the starch granules and then hydrolysed from within, along concentric holes ‐ a well established phenomenon in the starch granules from classical crops.