Cereal Chem 45:358 - 364. | VIEW
An Instrument for Objective Measurement of Degree of Milling and Color of Milled Rice.
R. A. Stermer. Copyright 1968 by the American Association of Cereal Chemists, Inc.
An instrument has been developed to provide an objective method for measuring three of the important quality factors of milled rice: degree of parboiling, color (general appearance), and degree of milling. Degree of milling measurements are made by comparing the light-transmittance properties of the rice sample at two specified wave lengths, 660 and 850 nanometers. Color of white milled rice and degree of parboiling of parboiled rice are objectively evaluated by measuring the lightness, a reflectance characteristic of the rice. A special optical unit permits either measurement to be made without transferring the sample from one instrument to another. Tests of the instrument with over 500 samples of white and parboiled milled rice samples show that the instrument is highly accurate in measuring degree of milling (r = 0.878) and color (r = 0.934) of white milled rice compared to visual grades determined by official inspectors. Correlation coefficients between meter reading and visual grades were somewhat lower for parboiled rice (r = 0.623) because of interactions that exist between degree of parboiling and degree of milling. Rice quality control and inspection or grading are potential uses of this instrument.