On the Relation Between Water Pools and Water Holding Capacity in Cod Muscle

Abstract

Low-field 1H nuclear magnetic resonance (NMR) relaxations were measured on muscle, minced muscle and centrifuged mince from cod that had been treated under various frozen and chill storage conditions. By using multi-way chemometrics, uniexponential profiles were obtained, from which the transverse relaxation times (T2-values) and the water pool sizes (m-values) were determined. Three pools of water were identified with the different relaxation times and m-values in the centrifuged samples reflecting the removal of loosely bound water. The m-values and the full NMR-signal decays were correlated to two measures of water holding capacity (WHC) in a way that WHC related to the original water content could be predicted well for the whole and the minced muscle. The centrifuged samples gave optimal predictions of WHC related to the dry matter content, probably because the centrifuged samples are similar to the samples used for measuring WHC. The twoWHC quantities were also correlated to the water distribution itself as measured by the relative pool sizes.