Comparative evaluation of native and modified starches produced from rice, cocoyam and cassava

Abstract

The study focused on comparative evaluation of native and modified starches produced from rice, cocoyam and cassava. Starch was  respectively extracted from rice, cocoyam and cassava. The starch from each of the food material was divided into two parts. One part  was modified while the other served as the raw counterpart giving a total of six samples. The functional, pasting and physical properties  of the samples were analyzed. The results obtained for functional properties of the starches ranges from 1.21% to 3.82% (water  absorption capacity), 0.26% to 0.85% (Bulk density), 0.84% to 2.49% (oil absorption capacity), 1.12% to 3.61% (swelling capacity), 1.61 to  7.63±0.04% (foaming capacity) and 6.34±0.05 to 6.56±0.02% (pH). Significant (p<0.05) differences were observed from the functional  properties of the starches due to modification. The pasting properties analyzed were, peak, trough, breakdown, final and setback  viscosities as well as pasting temperature and peak time with their values ranging from 96.40 to 216.16RVU, 32.32 to 163.94RVU, 17.89 to  64.51RVU, 59.33 to 276.3RVU, 25.24 to 111.39RVU, 60.78 to 83.26 0C and 3.80 to 6.00 minutes respectively. All the parameters analyzed for  pasting properties as well as physical properties (solubility, pH, etc.) differed significantly (p<0.05) from each other. The study generally  proved that modification enhanced the functional, pasting and physical properties of the respective starch samples. The modified starches are therefore recommended for inclusion in food formulation where their qualities can be harnessed.