Effects of Formaldehyde on Salt Extractable Proteins of Gadoid Muscle

1973 ◽  
Vol 30 (8) ◽  
pp. 1205-1213 ◽  
Author(s):  
C. H. Castell ◽  
B. Smith ◽  
W. J. Dyer
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Frozen Storage ◽  
Active Protein ◽  
Muscle Enzyme ◽  
Trimethylamine Oxide ◽  
Extractable Protein ◽  
Silver Hake ◽  
Merluccius Bilinearis ◽  
Fish Proteins

Addition of formaldehyde to fresh cod muscle, to give concentrations of 10 to 200 ppm, brought about marked decreases in the extractable protein content during holding periods of 24 hr or less at 0 C. Similar levels of formaldehyde, produced during frozen storage of gadoid (Atlantic cod, Gadus morhua, pollock, Pollachius virens, cusk, Brosme brosme, and silver hake, Merluccius bilinearis), fillets at −5 C, brought about similar reductions in the extractable proteins. Comparative tests showed that, in the concentrations normally encountered in deteriorating frozen gadoid fillets, formaldehyde was a much more active protein-insolubilizing agent than free fatty acid. It is evident that in these protein changes more than one mechanism is involved. Observed species-differences in the extent to which fish proteins became insolubilized during storage appeared to be related to presence or absence of these different mechanisms. The more rapid and more extensive denaturation of most gadoid fillets in frozen storage than of fillets of nongadoid species appears to be directly related to the presence of muscle enzyme of the former group that is capable of producing formaldehyde from trimethylamine oxide, which is absent in the muscle of the nongadoid species so far tested.

Comparison of Changes in Trimethylamine, Dimethylamine, and Extractable Protein in Iced and Frozen Gadoid Fillets

1973 ◽  
Vol 30 (8) ◽  
pp. 1246-1248 ◽  
Author(s):  
C. H. Castell ◽  
W. E. Neal ◽  
J. Dale
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
The Other ◽  
Protein Nitrogen ◽  
Extractable Protein ◽  
Frozen Fish ◽  
Silver Hake ◽  
Merluccius Bilinearis

When fillets of Atlantic cod (Gadus morhua), pollock (Pollachius virens), cusk (Brosme brosme), and silver hake (Merluccius bilinearis) were iced and the opposite fillets frozen, large amounts of trimethylamine were rapidly produced in the iced fish but none was formed in the frozen fish within 60 days. Hake produced large, similar amounts of dimethylamine (DMA) in iced and frozen fillets. The other three species produced more DMA in the frozen than in the iced fillets, but always much less than in the hake. In both frozen and iced fish the production of DMA was accompanied by a corresponding decrease in extractable protein nitrogen.

Deteriorative Changes During Frozen Storage in Fillets and Minced Flesh of Silver Hake (Merluccius bilinearis) Processed from Round Fish Held in Ice and Refrigerated Sea Water

1976 ◽  
Vol 33 (11) ◽  
pp. 2560-2567 ◽  
Author(s):  
Doris Fraser Hiltz ◽  
Barbara Smith Lall ◽  
D. W. Lemon ◽  
W. J. Dyer
Keyword(s):  
Lipid Oxidation ◽  
Sea Water ◽  
Frozen Storage ◽  
Fat Content ◽  
Storage Life ◽  
High Fat ◽  
Lipid Hydrolysis ◽  
Extractable Protein ◽  
Silver Hake ◽  
Merluccius Bilinearis

During frozen storage at −10 C, deterioration in muscle of silver hake (Merluccius bilinearis) was marked by rapid and extensive production of dimethylamine, concomitant decrease in extractable protein, and by lipid hydrolysis. Evidence of lipid oxidation in this gadoid species of relatively high fat content (2–4%) was also obtained. In minced flesh the rates of deterioration were about twice as fast as in fillets. Holding round fish for up to 6 days in refrigerated sea water (RSW) at 0–1 C before processing extended the frozen storage life of fillets at −10 C by 2–3 wk and of minced flesh by 1 wk over that for comparable materials prepared from round fish held in ice. Materials prepared from winter (March) and summer (August) fish showed little or no difference in rates of deterioration. The susceptibility of silver hake to deterioration at −10 C is similar to cusk; deterioration is faster than in cod or haddock, but not as fast as in red hake (Urophycis chuss). In all silver hake materials negligible deterioration occurred during frozen storage at −26 C for up to 6 mo.During preprocessing storage of round silver hake in RSW, a firm texture and acceptable appearance were retained for several days longer than in round fish held in ice, where objectionable softening of the flesh occurred, particularly in summer-caught fish. Saturation of the sea water with CO2 retarded the onset of bacterial spoilage in RSW-held fish, which otherwise developed more rapidly than in iced fish.

Storage Life of Refrozen Silver Hake (Merluccius bilinearis) Processed as Fillets am Minced Flesh from Thawed, Stored, Round-Frozen Fish

1977 ◽  
Vol 34 (12) ◽  
pp. 2369-2373 ◽  
Author(s):  
Doris Fraser Hiltz ◽  
D. H. North ◽  
Barbara Smith Lall ◽  
R. A. Keith
Keyword(s):  
Key Words ◽  
Frozen Storage ◽  
Storage Life ◽  
Freeze Thaw ◽  
Acceptable Quality ◽  
Frozen Fish ◽  
Silver Hake ◽  
Merluccius Bilinearis ◽  
Protein Extractability

Refrozen silver hake (Merluccius bilinearis), processed as fillets and minced flesh after thawing of stored round fish that had been frozen within 14 h of capture, underwent rapid deterioration during storage at −18 °C compared with once-frozen control materials from the same lot of fish. The estimated maximum storage life of silver hake refrozen as fillets after 3 and 6 mo storage of the round fish at −25 °C was reduced to about 4.5 and 1 mo, respectively, from 10 mo for once-frozen control fillets. Quality of the refrozen materials immediately after thawing and refreezing was similar to that of the round-frozen fish, except after 6 mo, where some initial deterioration occurred, particularly in minced flesh. Minced flesh was more unstable in frozen storage than fillets. In all once- and twice-frozen materials, formation of dimethylamine occurred concomitantly with decrease in protein extractability. Round-frozen fish underwent no loss in protein extractability during 6 mo storage at −25 °C, but some lipid hydrolysis occurred. These results suggest that the freeze–thaw–refreeze process as applied to silver hake will yield a final product of acceptable quality provided that storage of the round fish does not exceed 3–4 mo and that the refrozen materials are marketed within a month after processing. Key words: silver hake, Merluccius bilinearis, refrozen storage, dimethylamine, minced flesh

Preheat Treatment for Improvement of Frozen Storage Stability at −10 C in Fillets and Minced Flesh of Silver Hake (Merluccius bilinearis)

1975 ◽  
Vol 32 (8) ◽  
pp. 1450-1454 ◽  
Author(s):  
Barbara Smith Lall ◽  
Alison R. Manzer ◽  
Doris Fraser Hiltz
Keyword(s):  
Fatty Acid ◽  
Free Fatty Acid ◽  
Storage Stability ◽  
Frozen Storage ◽  
Preheat Treatment ◽  
Fatty Acid Accumulation ◽  
Acid Accumulation ◽  
Fishery Products ◽  
Silver Hake ◽  
Merluccius Bilinearis

Dimethylamine (DMA) formation occurs in the muscle of silver hake (Merluccius bilinearis) during frozen storage. The rate of its formation in fillets and minced flesh during subsequent frozen storage for 1 mo at − 10 C is not affected by preheating at temperatures up to 60 C. Preheating to 80 C, however, greatly retards DMA development. Lipid hydrolysis (free fatty acid accumulation) is arrested by preheating to 60 C, but is little affected by preheating at temperatures up to 45 C. These deteriorative reactions are faster in minced flesh than in fillets, and in materials prepared from summer (spawning) fish than in those prepared from winter fish.In breaded fishery products, preheat treatment as presently practiced is insufficient to inactivate these deteriorative enzymic reactions in sensitive gadoid species such as the hakes and pollocks.

Protein Instability in Minced Flesh from Fillets and Frames of Several Commercial Atlantic Fishes During Storage at −5 C

1975 ◽  
Vol 32 (6) ◽  
pp. 775-783 ◽  
Author(s):  
J. R. Dingle ◽  
J. A. Hines
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Protein Solubility ◽  
Kidney Tissue ◽  
Rapid Loss ◽  
Atlantic Mackerel ◽  
Trimethylamine Oxide ◽  
Minced Fish ◽  
Protein Instability ◽  
Hippoglossoides Platessoides

Minced flesh of Atlantic cod (Gadus morhua) and pollock (Pollachius virens), recovered by means of meat-separator machines from frames left after filleting operations, suffered a rapid loss of protein solubility during storage at −5 C. This was due to the presence of kidney tissue which caused the formation of dimethylamine and formaldehyde from the trimethylamine oxide of the muscle. The minced flesh of witch flounder (Glyptocephalus cynoglossus), American plaice (Hippoglossoides platessoides), and Atlantic mackerel (Scomber scombrus) was relatively stable when mixed with homogenates of their own kidney tissue, but cod kidney caused the same changes in gray sole as it did in minced cod flesh. The exclusion of gadoid kidney and blood from minced fish preparations is recommended.

The diet of harbor porpoises (Phocoena phocoena (L.)) in coastal waters of Eastern Canada, with special reference to the Bay of Fundy

1974 ◽  
Vol 52 (6) ◽  
pp. 777-782 ◽  
Author(s):  
G. J. D. Smith ◽  
D. E. Gaskin
Keyword(s):  
Coastal Waters ◽  
Gadus Morhua ◽  
Stomach Contents ◽  
Clupea Harengus ◽  
Osmerus Mordax ◽  
Phocoena Phocoena ◽  
Eastern Canada ◽  
Silver Hake ◽  
Merluccius Bilinearis ◽  
Harbor Porpoises

Stomach contents of 81 harbor porpoises (Phocoena phocoena (L.)) collected from eastern Canadian coastal waters during 1969–1972 were examined. A total of 454 free otoliths and 54 undigested specimens representing a minimum of 281 fish, consisting of nine species in seven families, were recovered from the copious semidigested fish remains found in 52 of the stomachs. Clupea harengus (herring), Gadus morhua (cod), and Scomber scombrus (mackerel) otoliths accounted for more than 78% of the total. Osmerus mordax (smelt), Pollachius virens (pollock), Merluccius bilinearis (silver hake), Sebastes marinus (redfish), and Macrozoarces americanus (ocean pout) otoliths were also identified. Squid (Illex sp.), hagfish (Myxine glutinosa), and polychaetes (Nereis sp.) were identified in a few stomachs. Fifteen of the stomachs examined were empty or contained only fluid. Examination of the stomachs of the 16 smallest animals indicated that weaning occurred at body lengths of 100–104 cm.

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