The Separation of Grain by Projection. II. Systematic Differences in Physical Properties and Composition of Wheat Fractions

Analyses for test weight, 500-kernel weight, protein content, ash content, and hardness characteristics of fractions ot 13 samples of hard red winter wheat, obtained b>spectrometric separation, revealeci high negatile correlations in most cases between plumpness factors and protein and ash contents, and high positive correlations between plumpness factors and hardness, when the latter is determined with a single-stage instrument. T h e projection technic appears to provide a means for analyzing commercially mixed wheat for certain qualities of its components and i t may be applied practically to separate either high protein fractions or high test weight fractions from ordinary commercial grain. A preceding paper (3) has described a grain spectrometer capable ol separating wheat into numerous fractions differing progressively in test weight. This develop~nent prompted a more detailed analysis of the test weight, 500-kernel weight, protein content, ash content, anti hardness characteristics of fractions obtained from 15 samples of hard red winter wheat. Materials and Methods The 15 sail~ples of hard red winter wheat investigated in this study consisted of pure varieties and commercial grain grown in Kansas, Oklahoma, and Texas in the crop years 1952 and 1953. Description ot these samples is given in Table 1 which includes their origin and test weight. Quantities of 60 lb. of each sample were processed by projection in the grain spectrometer into as many as 16 fractions. The fractions at the extreme ends of the series of receiving hoppers (see Fig. 1 o i preceding paper), consisting of less than 100 g. of grain, were discarded. This produced from 12 to 14 fractions of each sarnple which were subjected to other tests. Test weight was determined by rneans of the Koerner weight-perbushel apparatus. A vacuum counter was used to count out 500 kernels and these were weighed to the nearest 0.01 g. Moisture, protein, and ash contents of the samples were determined as outlined in Cereal 1Manuscript received January 11, 1954. Contrlbution KO. 246, Department of Flour and Feed Milling Industries, and KO. 46, Department of Phys~cs, Kansas State College, Mdnbattan. This research was supported by a grant from the Millers' National Federation, Chicago, 111. 2Department of Flour and Feed Milling Industries. 3Department of Physics. Published in CEREAL CHEMISTRY 31:4 (July 1954), pp. 326-332. Published by The American Association of Cereal Chemists.