Measurement of Water Diffusivities in Barley Components Using Diffusion Weighted Imaging and Validation with a Drying Model
| Autor: | Marco L.H. Gruwel, Digvir S. Jayas, Prabal K. Ghosh |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Permeability (earth sciences)
Water transport Moisture Chemistry General Chemical Engineering Restricted Diffusion Analytical chemistry Effective diffusion coefficient Physical and Theoretical Chemistry Diffusion (business) Porosity Barley Magnetic resonance Modeling Pore geometry Restricted diffusion Water mobility Endosperm |
| Zdroj: | Drying Technology. 27:382-392 |
| ISSN: | 1532-2300 0737-3937 |
| DOI: | 10.1080/07373930802682973 |
| Popis: | Diffusion-weighted magnetic resonance imaging was used to determine water diffusion coefficients (D) in hull-less barley kernel components (endosperm and embryo) at 20.5±0.5°C. The D values in barley components were time-dependent and restricted in nature as indicated by the decrease in the apparent diffusion coefficient with increasing diffusion time (from 3 to 25 ms). A four-parameter Padé approximation model was used to estimate D and pore geometry (pore surface area–to-volume ratio, pore size, porosity, electrical conductivity and permeability of water) of the barley components after long diffusion time (t → ∞) using data obtained during a relatively short period of diffusion. The D of embryo and endosperm were 2.2±0.07 × 10−5 mm 2 2. Czuchajowska , Z. ; Klamczynski , A. ; Paszczynska , B. ; Baik , B.-K. Structure and functionality of barley starches . Cereal Chemistry 1998 , 75 ( 5 ), 747 – 754 . [CrossRef], [Web of Science ®] View all references/s and 1.0±0.10 × 10−5 mm 2 2. Czuchajowska , Z. ; Klamczynski , A. ; Paszczynska , B. ; Baik , B.-K. Structure and functionality of barley starches . Cereal Chemistry 1998 , 75 ( 5 ), 747 – 754 . [CrossRef], [Web of Science ®] View all references/s, respectively. These D values were used to simulate moisture and temperature patterns during the drying of a barley kernel using a two-dimensional simultaneous heat and moisture transfer model and compared with literature D values for validation purposes. Based on the comparison, the D values of barley components obtained from our study can be used to develop realistic models of water transport in barley during different postharvest processing operations (e.g., drying, kilning, steeping). |
| Databáze: | OpenAIRE |
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