Cereal Chem 54:345 - 351. | VIEW
Infrared Reflectance Spectroscopy for Estimation of Moisture of Whole Grain.
R. A. Stermer, Y. Pomeranz, and R. J. McGinty. Copyright 1977 by the American Association of Cereal Chemists, Inc.
A spectrophotometer employing the tilting-filter wheel principles developed by Karl Norris in the early 1970's was used to study the infrared (IR) reflectance properties of whole-kernel corn and sorghum grain. Reflectance properties were compared with oven moisture content to determine the feasibility of using IR spectroscopy for rapid estimation of the moisture content of whole grain. Spectral reflectance, at two selected groups of wavelengths, was measured wiht the tilting-filter wheel instrument. The IR reflectance readings were compared with oven moisture analyses by use of multiple regression analysis. Correlation coefficients were 0.959 for sorghum grain and 0.993 for corn for samples ranging in moisture content from 13 to 55%. REsults were similar (R = 0.997 and 0.974 for corn and sorghum, respectively) from a commercial IR instrument (Neotec-GQA-41). For native wet samples, standard errors of the estimate ranged from 0.8% for corn to 3.4% for s orghum grain. Electric moisture meters were also used to estimate the moisture contents; standard errors of estimate were reduced by applying a power curve regression analysis (y = axb) to the data since the readings were nonlinear above about 30%. However, in general, the standard errors of the estimate were higher for the electric mositure meters than for the IR methods. The IR method shows promise for rapid estimation of the moisture content of high-moisture whole grain. Certain modifications in the instrumentation are suggested for improvement of results.