Amino acid decarboxylase activity and other chemical characteristics as related to freshness loss in iced cod (Gadus morhua).
Biogenic amine levels and other biochemical indicators were measured to study the safety of and the loss of freshness in iced Atlantic cod. Biogenic amine content exhibited high variability during iced storage of Atlantic cod. Ornithine and lysine decarboxylase activity apparently increased at the end of the storage period. Amino acid activity was probably generated by endogenous amino acid decarboxylases of raw fish. No statistical differences were observed in the total volatile base fraction or in the ammonia or monomethylamine contents during iced storage. However, trimethylamine contents showed a significant exponential relationship with time and sensory score. Cod formed inosine as the major metabolite of IMP. The H and G indices showed a linear relationship with time and sensory score and served as good indicators of cod freshness quality. However, the K, Ki, and P indices showed a logarithmic relationship with time and sensory score. IMP, K, Ki, and P served as indicators of freshness lost during the early stages of chilled storage of cod.
Departament de Ciencia Animal i dels Aliments, Facultat de Veterinaria, Universitat Autonoma de Barcelona, Spain. manuela.hernandez@uab.es
M Manuela
MM
Hernández-Herrero
Guillaume
G
Duflos
Pierre
P
Malle
Stéphane
S
Bouquelet
D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000378:metabolism*; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D005399:Fishes / Q000378:metabolism* / Q000382:microbiology; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D005519:Food Preservation; D007053:Ice; D007700:Kinetics; D009812:Odorants; D017747:Seafood / Q000382:microbiology / Q000592:standards*; D013649:Taste
D001679:Biogenic Amines; D007053:Ice; D002262:Carboxy-Lyases