Cereal Chem 66:374-377   |  VIEW ARTICLE

Wheat Pentosans. II. Estimating Kernel Hardness and Pentosans in Water Extracts by Near- Infrared Reflectance.

B. H. Hong, G. L. Rubenthaler, and R. E. Allen. Copyright 1989 by the American Association of Cereal Chemists, Inc. 

Wheats of several market classes that varied widely in kernel hardness were extracted with water, methanol- chloroform, ethanol, sodium hydroxide, and various combinations of these solvents. The extracts and their corresponding residues were scanned by a near-infrared spectrometer and the reflectance values log (1/R) at all wavelengths were examined for a relationship to three types of pentosans and for kernel hardness. Water extracts of the whole wheat meals contained a component(s) at 1,366, 1,436, and 2,108 nm that highly correlated with hardness (r = 0.86). Attempts to identify the active component(s) by selective treatments of the extracts showed it was likely not a protein, lipid, or pentosan (hemicellulose). Measurement of water extracts significantly improved the near-infrared reflectance estimation of water-soluble, enzyme- extractable, and total pentosans in wheat compared with estimates made on dry whole wheat meal: r = 0.88 versus 0.84; 0.89 versus 0.68, and 0.94 versus 0.62, respectively.