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United States Department of Agriculture

Agricultural Research Service

Title: Moisture Adsorption Characteristics of Wheat and Barley

Author
item Casada, Mark

Submitted to: Transactions of the ASAE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 1, 2001
Publication Date: March 1, 2002
Citation: Casada, M. 2002. Moisture adsorption characteristics of wheat and barley. Transactions of the ASAE. 2002. 45(2):361-368.

Interpretive Summary: Computer simulations of grain storage have been developed in recent years as an aid to improve grain storage and reduce storage losses, using only data from moisture desorption from grain during drying. The accuracy and usefulness of the simulations is hampered due to insufficient data in the literature to predict rates of adsorption of moisture by wheat and barley during storage. In this study, wheat and barley samples at initial moisture contents typical of grain storage were exposed to a range of typical storage conditions to measure adsorption rates. The measured adsorption rates were lower than those of comparable desorption tests. The adsorption rates for barley were lower than for wheat, due to lower diffusion coefficients for the barley endosperm and germ as compared to wheat. The new adsorption data will allow grain storage modelers to evaluate the magnitude of the errors caused by using desorption data, and to improve the models. The resulting revised grain storage models may result in new recommendations for grain storage management and improved stored grain quality.

Technical Abstract: Moisture adsorption rates for stored grains are important for accurate modeling of drying and storage. Wheat and barley samples at initial moisture contents typical of grain storage were exposed to several levels of higher humidity at two temperatures to measure adsorption rates. The best fit to the data was achieved with the Page equation and the cellular diffusion equations. The adsorption rates were lower than those of comparable desorption tests. The adsorption rates for barley were lower than for wheat, due to lower diffusion coefficients for the barley endosperm and germ as compared to wheat.

Last Modified: 7/12/2014