Impact of Process Parameters on the Acid Modification of Potato Starch

Abstract

The acid-modification of a regular potato starch (PS) using the slurry process is systematically investigated. The hydrolysis parameters temperature (30, 40, and 50 °C), acid concentration (0.3, 0.6, and 0.9 M HCl), and reaction time (4, 10, and 20 h) are graded, and characteristics regarding the modification process as well as the resulting acid-thinned samples are analyzed based on size exclusion chromatography-multi angle laser light scattering-differential refractive index detection (SEC-MALS-DRI) experiments. The data are examined statistically. Significant impacts on the amount and the molecular composition of solubilized starch polymers are identified. Increasing parameter values increased the carbohydrate solubilization and concurrently decreased the weight average molar mass (Mw) of the dissolved starch. Moreover, the Mw of the resulting acid-thinned starch samples as well as the corresponding amylose fraction (AM) decreased incrementally with enhanced temperature, acid concentration, and hydrolysis time, respectively. The results indicated the simultaneous molecular degradation of both AM and amylopectin (AP) during the acid modification in slurry. The potential for preparing almost identical acid-thinned samples by applying combinations of different parameter specificities is shown.