Cereal Chem 64:407-411   |  VIEW ARTICLE

Near-Infrared Reflectance Spectra of Hard Red Winter Wheats Varying Widely in Protein Content and Breadmaking Potential.

G. L. Rubenthaler and Y. Pomeranz. Copyright 1987 by the American Association of Cereal Chemists, Inc. 

Near-infrared (NIR) reflectance spectra were determined on 173 hard red winter wheat flour samples. The flours included two groups of samples: 51 milled from six wheat selections and cultivars grown at one location for 11 years and 97 varietal and 25 station composites. The samples were selected to obtain a wide range in flour protein content (7.9-20.7%) and breadmaking quality. The correlation coefficient between protein content and loaf volume was only 0.308 because of the large variation in protein quality. Water absorption ranged from 48.0 to 76.0%, mixing time from 0.75 to 9.50 min, and loaf volume of bread baked from 100 g of flour from 568 to 1,328 cm3. The logs of 1/R reflectance calibrations were derived using a Technicon 500 scanning spectrophotometer in the range 1,100-2,400 nm. The data were correlated with protein content, water absorption, dough mixing time, and loaf volume. The linear multiple correlation coefficients between NIR reflectance at 1,870, 2,052, and 2,304 nm and water absorption were 0.898 and 0.932 in calibration and prediction samples, respectively; the standard error of estimate (SEE) was 1.8%. The linear multiple correlation coefficients between NIR reflectance at 1,604, 1,632, and 1,884 nm and log mixing time were 0.848 and 0.795 for the calibration and prediction samples, respectively, and SEE 0.12 (equivalent to 1.3 min). The linear multiple correlation coefficients between NIR reflectance at 1,506, 1,534, and 1,618 nm and loaf volume were 0.896 and 0.849 for the calibration and prediction samples, respectively, and SEE was 48 cm3. The correlation coefficient increased from 0.308 to 0.896 for the relation between protein and loaf volume or specific loaf volume, respectively, reflecting the ability of NIR to measure protein quality for breadmaking independently of protein quantity. There were differences in NIR reflectance calibration wavelengths responsible for breadmaking parameters in various groups of populations. This indicated a potential for using the spectra in varietal identification.