Cereal Chem 66:15-18   |  VIEW ARTICLE

Air-Aspirated Wheat Cleaning in Grading and in Separation by Functional Properties.

A. Bettge, G. L. Rubenthaler, and Y. Pomeranz. Copyright 1989 by the American Association of Cereal Chemists, Inc. 

Thirty-seven commercial wheat samples (17 soft white and 20 hard red) were graded by State of Washington/U.S. Dept. of Agriculture-Federal Grain Inspection Service inspectors for dockage and foreign material. The clean grain and dockage were recombined, mixed, and separated by the Carter dockage tester and the Kice dockage tester DT4 (KDT). The KDT operates on the principle of air aspiration. Results from the KDT apparatus at a low airflow were highly correlated (r = 0.889) with the results of the Federal Grain Inspection Service separation. At high airflow, the KDT also separated whole kernels of various densities. The separated kernels significantly differed in 1,000-kernel weight, ash, near-infrared hardness, and protein content from the portion of the sample passing through the system. The hard wheat samples also differed in kernel density (determined by helium pycnometer) between these fractions. Separated fractions were milled experimentally and evaluated in cookie making. The less dense fraction exhibited higher flour ash, protein, and mixograph absorption but lower flour yield and cookie diameter.