Starch-water, gluten-water, and flour-water model systems as well as straight-dough bread were investigated with (1)H NMR relaxometry using free induction decay and Carr-Purcell-Meiboom-Gill pulse sequences. Depending on the degree of interaction between polymers and water, different proton populations could be distinguished. The starch protons in the starch-water model gain mobility owing to amylopectin crystal melting, granule swelling, and amylose leaching, whereas water protons lose mobility due to increased interaction with starch polymers. Heating of the gluten-water sample induces no pronounced changes in proton distributions. Heating changes the proton distributions of the flour-water and starch-water models in a similar way, implying that the changes are primarily attributable to starch gelatinization. Proton distributions of the heated flour-water model system and those of fresh bread crumb are very similar. This allows identifying the different proton populations in bread on the basis of the results from the model systems.

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The potential of Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) for non‐invasively monitoring the subcellular and intercellular redistribution of water in cellular tissue during drying and freezing processes is assessed and it is concluded that despite exciting advances in NMR micro‐imaging and NMR microscopy, nonspatially resolved NMR relaxation and diffusion techniques still provide the best probes of subcellular water compartmentation in tissue. The power of the NMR relaxation technique is illustrated by using the changes in the distribution of NMR water proton transverse relaxation times to monitor the subcellular compartmentation of water and ice during the drying and freezing of parenchyma apple tissue. The NMR drying data are analysed with a numerical model of the cell and show that mild air‐drying in a fluidized bed results in loss of water from the vacuolar compartment, but not from the cytoplasm or cell wall regions. The loss of vacuolar water is associated with overall shrinkage of the cell and only a slight increase in air space. During freezing the vacuolar compartment is found to be the first to freeze, with the cytoplasmic and cell wall compartments only freezing at much lower temperatures. Freeze‐drying apple tissue gives much lower water contents than fluidized bed drying, but the NMR data confirms that it destroys membrane integrity and causes cell wall collapse.