Abstract
The effects of nitrogen topdressing at anthesis on the milling property, physical dough characteristics and bread-making quality of wheat were investigated with two cultivars, “Minaminokaori” and “Nishinokaori” in Northern Kyusyu. The protein content of grain increased as the amount of topdressed nitrogen increased, at a rate of about 1% per 2 g m-2 nitrogen topdressing, and the protein content reached 11.5% which is the standard value of protein content when 2 g m-2 was applied. Valorimeter value of farinogram increased as the amount of applied nitrogen increased. “Nishinokaori” had lower dough development time, valorimeter value of farinogram and extensogram characteristics than “Minaminokaori”. The volume-to-weight ratio of loaf increased when 4 g m-2 nitrogen was topdressed in “Minaminokaori”, but only slightly in “Nishinokaori”. “Nishinokaori” was considered to have a lower gluten index and sedimentation value, and therefore it had a lower quality of gluten than “Minaminokaori”. Bread score tended to be superior when the amount of applied nitrogen was increased, and the multiple regression analysis showed a large contribution of valorimeter value and protein content of the 60% extraction flour to bread score. Comparison of the variance component between the amount of nitrogen topdressing at anthesis and variety indicated that the protein content of 60% extraction flour greatly varied with the amount of topdressing, and that physical dough characteristics and the volume-to-weight ratio of loaf greatly varied with the variety.
