Study on physicochemical characteristics of waxy potato starch in comparison with other waxy starches

摘要

The physicochemical properties of wx potato, wx corn, and wx rice starches were examined and compared, wx potato starch displayed the B-type XRD pattern, whereas wx rice and wx corn displayed the A-type. Shapes of wx potato starch were oval or slightly round, wx corn and wx rice starch granules were polygonal. AM contents of the three starches were between 1.0 and 1.5%. Rapid viscosity analyzer data showed initial pasting temperatures of wx potato, wx corn, and wx rice starches as 69.6, 75.4, and 76.8°C, respectively, peak viscosity, breakdown, and setback of wx potato starch were 2114,1084, and 4 mPa s. Using DSC, onset temperature of gelatinization of wx potato starch was 5.5-7.2°C higher than those of wx rice and wx corn starches. The thermal enthalpies of the starches studied in our laboratory were in the range of 0.2268-1.9900 J/g with decreasing order of wx potato > wx corn > wx rice starch.