Abstract
Starch granules were prepared from tubers of Chinese arrowhead (Sagittaria trifolia L. var. edu-lis (Sieb.) Ohwi), 3 cultivars: Aokuwai (Ao), Shirokuwai (Shi) and Suitakuwai (Sui), and their 6 F, lines: Ao×Ao, Ao×Shi, Ao×Sui, Shi×Ao, Shi×Sui and Sui×Sui. The amylose content of the starches determined by amperometric iodotitrimetry were in a range of 28.2-29.9% and 26.6-31.3% by gel-permeation chromatography (GPC) of isoamylase-debranched starches. High performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD) of isoamylase-debranched starches showed the starches had unique amylopectin short chain length distributions of increased amounts of chains with DP 6 and 7, and decreased amounts of chains with DP 9 compared with waxy maize amylopectin. The X-ray diffractograms of the starches showed A type patterns. Among the 3 cultivars, the granular size and temperature of gelatinization by DSC of the starches were in the ascending order of Shi > Ao > Sui, and starch-granule digestibility by amyl-ase and solubility and swelling power at 70°C of the starches were in the descending order of Shi >Ao>Sui. There were positive correlations between starch-granule digestibility by amylase and either solubility at 60°C and 70°C or swelling power at 60°C and 70°C of the starches, and negative correlations between starch-granule digestibilities by amylase and temperatures of gelatinization (To and Tp) by DSC of the starches.
