Cereal Chem 69:137-141   |  VIEW ARTICLE

Estimation of Milling Efficiency: Prediction of Flour Refinement by the Measurement of Pericarp Fluorescence.

S. J. Symons and J. E. Dexter. Copyright 1992 by the American Association of Cereal Chemists, Inc. 

Millstreams from pilot-scale millings of commercially grown wheat representing different crop years and several Canadian wheat classes were used to evaluate the measurement of flour refinement by fluorescence imaging of pericarp tissue. Flour fluorescence was measured using a No. 09 filter combination (excitation 450-490 nm, emission greater than 520 nm) specific for pericarp. Pericarp fluorescence was able to discriminate between four groups of divide flours (first patent, second patent, straight grade, and clears) prepared from No. 1 Canada Western Red Spring (CWRS) millstreams. However, the measurements were not fully within each divide flour group. The relationships of fluorescence measurements to flour ash content, grade color, and the tristimulus brightness component (L*) for millings of Grain Research Laboratory harvest survey No. 1 CWRS eastern and western prairie composites from three successive crop years were completely homogeneous between crop years and growing location. Comparisons of millstreams from composites of the No. 1 grade of Canada Western Red Winter, Canada Prairie Spring (red), and Canada Western Utility wheat classes showed highly significant relationships between pericarp fluorescence and flour ash, flour grade color, and L*. The relationships between pericarp fluorescence and the flour refinement indices for the different wheat classes were heterogeneous, however, indicating that the prediction of ash content or flour color established from millstreams obtained from one wheat class connot be extrapolated to other wheat classes.