Summary:
The distribution and characteristics of water in the muscle of various commercially available Icelandic heavily salted Atlantic cod products were analyzed with proton magnetic resonance methods. The products varied in choice of catching method, in pre- or post-rigor processing, flattening or filleting cut, and pre-salting technique (brine injection with salt with / without polyphosphates, brining and pickling) and choice of brine-injection instruments.
All products had heterogeneous water distributions, but the level of heterogeneity was dependent on the handling during processing. Brine injection led to salt-induced swelling, which effect remained after the kench dry salting step. Double brine injection induced needle traces in the muscle, even after kench salting. Relaxation time analysis indicated that pickle salted products had the highest degree of protein denaturation in the muscle amongst the analyzed pre-salting methods. The multi-parametric analysis indicated how powerful the MR methods are for process and product characterization and optimization.