Segregating hard red winter wheat into dough factor groups using single kernel measurements and whole grain protein analysis

In accordance with the Grain Quality Acts of 1986 and 1990, scientists at K ansas State University are studying the feasibility of implementing a quali ty-based marketing system for hard red winter (HRW) wheat in the Southern P lains. This research addresses the development of a segregation system that uses the single kernel characterization system and the whole grain near-in frared analyzer to evaluate the milling and baking quality of wheat as a si ngle value called "dough factor". This single value represents the amount o f flour-water dough that can be produced from a given unit of wheat. Sample s of HRW wheat (approximate to 100 per location) were collected at five Kan sas country elevators during the 1995 and 1996 harvests. After the dough fa ctor was measured for individual samples, the samples were composited into seven dough factor groups to establish binning and segregation strategies a nd to explore the relationship between wheat quality measurements and dough factor groups. Results showed that dough factor groups were significantly different from each other and that dough factor groups were related (P < 0. 05) to increases in test weight, single kernel weight, single kernel size, flour yield, and mixing time. Although locations showed year-to-year variab ility for test weight, kernel weight, and kernel size, the differences amon g dough factor groups for these characteristics across locations were consi stent, indicating that the mean values within dough factor groups are simil ar regardless of location. The lack of significant differences in protein c ontent among dough factor groups was attributable to high variability withi n dough factor groups between years. High protein values were present in lo w and high dough factor groups, indicating that protein content alone is no t a good indicator of wheat quality. Patterns of differences in wheat quali ty characteristics among dough factor groups suggest that the seven groups studied can be reduced to three groups: <107, 107-112.9, greater than or eq ual to 113. This study demonstrates that dough factor as a segregation and marketing tool is related to single kernel characteristics, differentiates wheats of varying quality, and reflects the end-use value of wheat.