Thawing, Refreezing and Frozen Storage Effects on Muscle Functionality and Sensory Attributes of Frozen Cod (Gadus morhua)

Thawing and re‐freezing of cod fillet blocks did not necessarily result in greater deterioration (relative to a ‘once frozen’ control) of cooked fish sensory attributes after 9 months frozen storage at –22°C. Thawed and refrozen fish muscle displayed a faster decline in myofibril protein solubility than once frozen controls and had reduced water‐holding capacity but analysis of proton spin‐spin relaxation times indicated no change in water location. The decline in protein solubility was not caused by complete protein unfolding. Long thawing times (30 hr) before re‐freezing and storage resulted in cooked fish with more gray appearance and more stale flavor. Changes in fish muscle functionality did not enable direct inference of sensory attributes.