Dextrose Equivalent Analysis of Acid Hydrolysed Corn and Cassava Starch Sourced from Ghana

Abstract

The use of acid hydrolysis to convert starch into dextrose can be difficult and time-consuming. The process requires high acidic medium and temperature which tends to contaminate the end-product hydrolysate. Therefore, this research was carried out to obtain optimum conditions necessary to produce a high and quality Dextrose Equivalent by varying the initial starch concentration and acid volume. The mass of corn and cassava starch and the total hydrochloric acid volume used for the hydrolysis ranged from 100 to 400 g and 1-3 liters respectively. The results showed that the optimum conditions for hydrolyzing the two starch types to Dextrose were within a temperature range of 100°C-120°C, 12 w/w% starch concentration, 4 atmospheric pressure and 30 minutes operating time. The optimum conditions produced a Dextrose Equivalent of 79.80% and 78.66% for cassava and corn starch respectively. The amount of dextrose produced in the process is a function of temperature, pressure, acid volume, operating time and initial starch concentration. Experimental results also confirmed an increase in pH of the hydrolysate with a temperature rise, and this influenced the Dextrose quality. The outcomes provided new findings to complement existing outcomes on how initial starch concentration and acid volume affect Dextrose Equivalent by acid-type hydrolysis.