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A magnetic resonance study of water uptake in whole barley kernels
Author(s) -
Gruwel Marco L. H.,
Chatson Brock,
Yin Xiang S.,
Abrams Suzanne
Publication year - 2001
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1046/j.1365-2621.2001.00445.x
Subject(s) - imbibition , fick's laws of diffusion , viscosity , distilled water , chemistry , relaxation (psychology) , analytical chemistry (journal) , nuclear magnetic resonance , thermodynamics , diffusion , physics , chromatography , germination , botany , psychology , social psychology , biology
Summary The water uptake by barley kernels was followed by 1 H NMR spectroscopy. A model was used to explain the first 7 h of imbibition. Measurement of the 1 H spin‐lattice relaxation rate, R 1 , showed that during the first 7 h of imbibition, water uptake is dominated by a purely diffusive process with a dependence, where D is the diffusion constant and t is time. While increasing during the first 7 h of imbibition, R 1 slowly but continuously decreased afterwards. The observed changes in R 1 with imbibition time allowed discrimination between the first two phases in water uptake, as generally observed in germinating seeds. The second phase was characterized by a slow but continuous decrease in R 1 , indicating a redistribution of water within the kernel. Observed spin‐lattice relaxation rates, R 1 , were treated as a superposition of rates from water molecules in two different physical phases; a mobile and a less mobile phase. Using the Stokes–Einstein–Debye theory for viscosity, the overall water viscosity within the kernel was determined using the two‐phase model to describe water mobility.