Australian salt-noodle flours and their starches compared to U.S. wheat flours and their starches

Abstract

The properties of flours and starches from three soft wheats segregated in Western Australia for noodlemaking were compared with those of 12 wheats from the United States representing six classes. Also included were seven Korean noodle flours and their starches. Wheat starches were isolated from the flours in =65% recovery by dough washing and in =90% yield by protease digestion. Compared to the Australian flours, three U.S. soft red wheat flours had 10% more total lipids and nonstarch lipids, whereas Western White wheat flour had less. Total lipids were low in the Australian flours, but nonstarch lipids were average. The swelling powers (SP) of the three Australian flours at 92.5°C ranged from 20.0 to 21.1 g/g, whereas those of the 12 U.S. flours ranged from 14.8 to 19.0 g/g. Multiple regression analysis showed that the SP of the 22 flours were positively correlated (r 2 = 0.93, P = 0.001) with the SP of the starches and negatively correlated with flour protein levels. The high SP (92.5) of an Australian noodle-segregate flour was attributed to its low protein level and to its starch's low amylose and lipid levels. Gels prepared at 6% from Gamenya starch, one of the high-swelling Australian wheat starches, gave a high storage modulus (G') in dynamic rheological tests when compared to the gels of low-swelling wheat starches. When the starch concentrations in gels were increased to 10.5%, the G' increased less for Gamenya than for the low-swelling starches, especially one from a soft wheat (Geneva). Low-swelling starch from the hard red winter wheat Karl gave gels at 8.0-10.5% solids with G' values that almost matched those of Gamenya. The size distributions of starch granules from Karl and Geneva wheats were the lowest and highest, respectively, among the starches tested.