PREDICTING PROTEIN-COMPOSITION, BIOCHEMICAL-PROPERTIES, AND DOUGH-HANDLING PROPERTIES OF HARD RED WINTER-WHEAT FLOUR BY NEAR-INFRARED REFLECTANCE

Breadmaking quality in wheat is one of several considerations that pla nt breeders face when developing new cultivars. In routine breeding pr ograms, quality is assessed by small-scale dough-handling and bake tes ts, and to some extent, by biochemical analysis of gluten proteins. An alternative, not yet fully examined, method for wheat flour quality a ssessment is near-infrared reflectance (NIR) spectrophotometry. The pr esent study was performed on 30 genotypes of hard red winter wheat gro wn during two crop years at eight to nine locations in the Great Plain s area of the United States. Biochemical testing consisted of measurin g protein fractions from size-exclusion HPLC (M-r > 100k, M-r 25-100k, and M-r < 25k designated as glutenin, gliadins, and albumin and globu lins, respectively), pentosan content, and SDS sedimentation volume. D ough-handling properties were measured on a mixograph and recorded as the time to peak dough development, the peak resistance, the width of the mixing curve, and the width of the curve at 2 min past peak. Parti al least squares analyses on diffuse NIR spectra (1,100-2,498 nm) were developed for each constituent or property When applied to a separate validation set, MR models for glutenin content, gliadin content, SDS sedimentation volume, and mixograph peak resistance demonstrated refer ence vs. predicted correlations ranging from r = 0.87 to r = 0.94. Suc h models were considered sufficiently accurate for screening purposes in breeding programs. NIR spectra were responsive to each constituent or property at a level higher than expected from a correlation between the constituent or property and protein content (recognizing that pro tein content is modeled by NIR with high accuracy).