Amino acid composition of fish meat after different frozen storage periods

A new approach is used to investigate one definite aspect of frozen ocean fish (including scad, mackerel, gray/humped rock cod, red/black sea bream, belted bonito-filleted) after different terms of storage at -35°C. We intended to prove whether the season, place and depth of catch influence the amino acid content of the frozen fish meat. The analysis of the bound amino acids in the proteins of the fish muscle in intervals of 3, 6, 9 and 12 months after draught has shown that even to the end of the storage the irreplaceable amino acids remain unchanged and slight deviations are observed in the amount of the others. The appearance of diaminopimelic acid (DAP) shows a microbiological contamination, especially after long storage, but this very low temperature does not allow a drastic increase of the psychrophyles. The methionine sulfoxide (Ms) which appeared also, shows only an oxidation of the metliionine which is common in long storage of samples. © 2000 by The Haworth Press, Inc. All rights reserved.