Taste Panel Assessment of Cod Fillets After Single and Double Freezing

Abstract

Taste panel assessment is reported for Atlantic cod (Gadus morhua) frozen once and twice, and stored at −23 C. The fish were bled, gutted, and iced immediately after capture, and frozen as fillets or dressed fish before, during, and after rigor mortis. Dressed fish were thawed later in recirculated tap water, then processed, refrozen, and stored as fillets. The procedure was conducted three times (June 27, July 19, July 30) during the inshore trap fishery and twice (March and October) during the offshore Grand Bank fishery.For trap-caught landings, the quality of the stored fillets frozen once depended upon the season of catch; for Grand Bank cod, upon the time and place of catching. Trap fish, feeding lightly, caught in cold water in June, were of best quality, grades equalling 70 and over after 20 weeks storage. Those caught on July 30 while feeding heavily in warm water were second; the July 19 fish, obtained under nearly similar conditions, were not significantly poorer than those taken on July 30 and were still acceptable. March landings of Grand Bank fish, once frozen, scored over 70 after 20 weeks storage; October landings only 40 (borderline quality) after 30 weeks. Physiochemical and chemical assessment confirmed the poor quality of the latter.Thawing, refreezing, and storage of June trap fish longer than a few weeks resulted in poor but still acceptable samples. The stored product was soon similar in quality to samples prepared from July landings. In contrast, twice-frozen samples prepared from the March landings from the Grand Bank continued to score high, 70 after 28 weeks storage. Refrozen October samples from the Grand Bank yielded much lower scores, similar to those given the once-frozen samples of the same catch. Thus, in general, an acceptable or better twice-frozen product was obtained by starting with material well handled and quickly chilled, from either the inshore or offshore fishery.