The Effect of Freeze-Thawing on the Magnetic Resonance Imaging Parameters of Cod and Mackerel

Magnetic Resonance Imaging (MRI) was used to measure the MR parameters of water (T1, T2, Tsat1, Msat, M0and the Magnetisation Transfer (MT) rate) in fresh and frozen-thawed cod (Gadus morhua) and mackerel (Scomber scombrus); those species were chosen to be representative of the demersal and pelagic marine fish, respectively. Samples of a cod were obtained `freshʹ from a local fish market and as cod fillets in an Individually Quick Frozen (IQF) state. The extent of deterioration during storage was monitored over 2, 4, 8 and 12 wk periods. It was found that T1, Tsat1and MT rate were particularly sensitive to the effects of frozen storage.