Effects of Water and Dielectric Thawing Processes on Shelf Life of Double-Frozen Cod and Redfish

• Published in: Journal of the Fisheries Research Board of Canada
• Main Authors: MacCallum, W. A., Chalker, Dorothy A., Dyer, W. J., Idler, D. R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1967
• Subjects: General Medicine; Gadus morhua
• Online Access: http://dx.doi.org/10.1139/f67-011; http://www.nrcresearchpress.com/doi/pdf/10.1139/f67-011

Analytical taste panel results showed that immersion-thawing in tap water at two different temperatures (7.2 and 15.5 C) and dielectric thawing (at 38 Mc/s) had similar effects on the cold-storage life (at −23 C) of processed, refrozen fillets of cod (Gadus morhua) and of redfish (Sebastes marinus mentella) (water thawing at 15.5 C only).Refrozen fillets from Grand Bank cod, captured in March, iced 4 days and frozen, water-thawed, and reprocessed as above, though not quite as good as once-frozen controls, were still of good quality after 35 weeks storage.Lightly feeding June trap cod, captured in cool (4 C) inshore water, iced, and frozen before and during rigor mortis, then water-thawed and refrozen, were still acceptable after 28 weeks storage, but were considerably poorer than samples frozen once. Quality was similar at both thawing, temperatures (7.2 and 15.5 C) and both conditions of rigor at first freezing.Heavily feeding July trap cod, captured in warmer (7–9 C) inshore water, similarly handled and similarly processed and refrozen following thawing in water at 15.5 C or dielectrically, were of just acceptable quality up to 32 weeks in storage and were similar to samples frozen once.Grand Bank redfish, similarly frozen before and during rigor and later processed and refrozen, maintained very acceptable quality up to 28–34 weeks with both thawing procedures and state of rigor at freezing and were equal to samples frozen once. Thiobarbituric acid values increased on storage.