Milling and flour pasting properties of waxy endosperm mutant lines of bread wheat (Triticum aestivum L)

Two waxy endosperm mutant lines, K107Wx1 and K107Wx2, derived from a bread wheat cultivar, Kanto 107, had a lower flour yield in test milling and a lower peak temperature in flour pasting measurement than their parent. Starch content in the kernel of waxy mutants was low, while fat and (1→3),(1→4)-β-D-glucan content was high compared with cv Kanto 107, but protein content was similar for all of them. Waxy mutants had less α-amylase activity than their non-waxy parent, and had lower peak viscosity of flour paste in the pasting medium of water. A pasting test in silver nitrate solution increased peak viscosity in both waxy and non-waxy flours. The viscosity of waxy flour paste rapidly increased above 60°C, while that of non-waxy flour paste increased gradually at 60–80°C. The difference in pasting behaviour was attributed to the presence of amylose in starch granules. © 1999 Society of Chemical Industry