Subzero temperature NMR Imaging of the nonfreezing water in potato cylinders is used to study freeze‐drying kinetics. the analysis of the distribution of transverse relaxation rates of the samples between +5C and ‐25C is used to determine the state of water in potato tissue and establish imaging protocols. the evolution of the Residual Water Content, the diameter of the frozen core observed visually and of the nonfreezing water detected by NMR Imaging, are monitored as a function of the freeze‐drying time. These results are interpreted with a theoretical model based on pure sublimation from the surface of a finite cyl
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