Cereal Chem 62:41-46   |  VIEW ARTICLE
Determination of Hardness in Mixtures of Hard Red Winter and Soft Red Winter Wheats. I. Bulk Samples.

Y. Pomeranz, S. Afework, and F. S. Lai. Copyright 1985 by the American Association of Cereal Chemists, Inc. 

Four methods were used to determine wheat hardness: time to grind and resistance to grinding wheat, and particle size index and near infrared reflectance (NIR) at 1,680 nm of ground wheat. The methods were used to evaluate 12 soft red winter (SRW) and 12 hard red winter (HRW) wheats that differed widely in hardness. Coefficients of variation were much higher for the four hardness measurments in the SRW than in the HRW wheats. There was little overlap in hardness parameters between the HRW and SRW wheats. Hardness in blends of HRW and SRW wheats was determined in four groups of samples: mixtures of Arkan (HRW) and Arthur (SRW) prepared in the laboratory; four sets of coded mixtures of Arkan and Arthur prepared by the Federal Grain Inspection Service (FGIS), U.S. Department of Agriculture; eight coded blends of eight different HRW and eight different SRW wheat varieties or selections prepared by the FGIS; and five blends of five commercial samples, each, of HRW and SRW wheats provided by FGIS and mixed in the laboratory. Generally, NIR reflectance was linearly related and effective in determining the HRW:SRW wheat ratios in blends. The standard errors of estimate for the four methods varied and depended, among others, on the percent of admixed wheat. The hardness methods were most powerful in determining admixtures of large amounts of one class of wheat to another, especially, if the hardness of the individual wheats used for blending was known.