A THERMAL-ANALYSIS INVESTIGATION OF PARTIALLY HYDROLYZED STARCH

Porous starch granules are formed by the partial hydrolysis of starch using glucoamylases. These porous granules can be used to reveal struc tural information about the starch itself. Starches from four differen t sources were used as substrates in this study. These starches were p artially hydrolyzed using glucoamylase. The material left behind after enzyme treatment was then treated to thermal analysis using TG and DS C to characterize the hydrolysis product. A structural analysis was ma de using SEM and powder X-ray diffraction to investigate whether the p artial hydrolysis had any effect on the granule structure and the crys tallinity of the different starches. In each case, except for potato s tarch, combustion in air took place at a lower temperature. On the oth er hand, the gelatinization temperature increased as the porosity incr eased. (C) 1998 Elsevier Science B.V.