Effect of controlled and modified atmospheres on the production of biogenic amines and free amino acids during storage of hake

Free amino acids (FAAs) and biogenic amines were determined in whole hake (Merluccius merluccius L) stored in bulk under controlled or modified atmosphere (60% CO2:15% O2:25% N2) for 12 days at 2°C and followed by storage in trays either under the same special atmosphere or under air for 31 days at 2°C, which was the control. At the end of the storage, significant differences were observed (P≤0.05) in the amino acids isoleucine, leucine, methionine, phenylalanine, valine, glutamic acid and glycine between the control lot and the treated lots, and it was the control lot which exhibited the highest concentrations. However, the lots kept in special atmospheres exhibited higher levels of alanine, β-alanine, threonine, and tryptophan than the control lot. There was no relationship between the decreases in histidine, tyrosine, lysine, arginine and ornithine initial concentrations and the increases in their corresponding biogenic amine concentrations (histamine, tyramine, cadaverine, agmatine and putrescine, respectively) which appeared as a result of decomposition of fish by decarboxylation of the FAA. Significant differences (P≤0.05) were observed in the biogenic amine concentrations among the lots kept under special atmospheres. The bulk-stored lot in controlled atmosphere for the first 12 days and then packed in trays with modified atmospheres exhibited the lowest levels of biogenic amines, except for agmatine, throughout storage. © Springer-Verlag 2002.Peer Reviewe