Distribution of Water in Fresh Cod

Low-field ¹H nuclear magnetic resonance (NMR) transverse relaxation was used to measure water mobility and distribution of water in fresh cod fillets. The NMR relaxations were analysed with the so-called SLICING method giving uni-exponential profiles from which the transverse relaxation time (T₂-values) and the relative sizes of the water populations were calculated. Two water populations with the T₂-values of 50 and 94 ms were obtained. The shortest relaxation time was primarily found near the head, and water with the longest relaxation time was primarily found near the tail. This variation can be explained by the smaller muscle cells and muscle fibers in the tail, which may influence the distributions of water into the different pools. The amount of one of the water populations was correlated to the overall water content with a correlation coefficient of −0.94.