Cereal Chem. 73 (5):567-570  |  VIEW ARTICLE

Grain Quality

Determining Endosperm Texture of Developing Hard and Soft Red Winter Wheats Dried by Different Methods Using the Single-Kernel Wheat Characterization System.

D. B. Bechtel (1,2), J. D. Wilson (1), and C. R. Martin (1). (1) U. S. Grain Marketing Research Laboratory, USDA-ARS, 1515 College Avenue, Manhattan, KS 66502. Mention of company or trade names is for purposes of description only and does not imply endorsement by the U.S. Department of Agriculture. (2) Corresponding author. E-mail: <don@usgmrl.ksu.edu> Accepted June 12, 1996. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. American Association of Cereal Chemists, Inc., 1996. 

Field-grown hard (Pioneer 2163, Arkan, Karl, Newton, TAM 107, and TAM 200) and soft (Caldwell and Clark) red winter wheats were harvested at 15, 18, 21, 23, 25, 28, and 35 days after flowering (DAF). Wheat was dried by a variety of methods: air-dried in the spike at 28ºC; oven-dried in the spike at 40ºC; freeze-dried following both freezing and threshing under liquid nitrogen; field-dried mature grain; and freeze-thawed and air-dried, in which samples were first frozen in liquid nitrogen, thawed at room temperature (23ºC), and then air-dried in the spike at 28ºC. The U.S. Grain Marketing Laboratory's single kernel wheat characterization system was used to measure various grain parameters including the hardness of individual kernels. Air-dried and oven-dried samples generally had similar hardness indices when compared to that of mature grain. Soft wheats were also softer than hard samples when dried by these two methods. Freeze-dried grain had similar low values of hardness for samples harvested between 15 and 28 DAF, but mature 35 DAF grains had normal hardness indices. Freeze-thawed samples had hardness indices slightly higher than those of either air- or oven-dried grain.