Various methods of nuclear magnetic resonance (NMR) and their application for determinig water- and temperature distributions as well as self diffusion coefficients during food processing operations are presented. Starting from the physical basics of the magnetic resonance, various NMR applications are shown, which may contribute to a more comprehensive understanding of the food processes: Presented examples are the determination of water distributions during the rehydration of dried samples, of temperature distributions during a microwave heating process and of self diffusion coefficients during microwave vacuum drying. These observation time dependent self diffusion coefficients may be used to receive further information about the internal tissue structure, like tortuosity and pore radii.