Comparison of Morphology and Physicochemical Properties of Starch Among 3 Arrowhead Varieties

Arrowhead (Sagittaria trifolia var. sinensis) is a source of starch worldwide, but arrowhead starch has been rarely studied. In this work, starch was separated from arrowhead corm. The morphology and physicochemical properties of starch were then investigated and compared among 3 different arrowhead varieties (Purple‐corm, Hongta, and Japanese). Results showed that starches from the 3 varieties similarly featured an oval shape containing a visible polarization cross, a C_A‐type crystalline structure, and an ordered structure in the external granule region. However, starch content, granule size, crystal characteristics, and pasting properties differed among the 3 varieties. Japanese arrowhead exhibited the highest starch content and degree of ordered structure in the external granule region, as well as onset, peak, and final gelatinization temperature. Purple‐corm arrowhead starch demonstrated the highest amylose content and relative degree of crystallinity, smallest granule size, and lowest swelling power and solubility. Purple‐corm arrowhead starch also showed the highest gelatinization enthalpy, as well as peak, trough, final, and setback viscosities. This starch further presented the lowest breakdown viscosity and degree of hydrolysis by HCl and porcine pancreatic α‐amylase. These findings can provide useful references for arrowhead variety selection in food and nonfood industries.