Influence of Some Preservatives on the Quality of Prepacked Cod Fillets in Relation to the Oxygen Permeability of the Film

S ummary : The deterioration of prepacked cod fillets in relation to different concentrations of citric acid (HC) and of potassium sorbate (PS) was studied bacteriologically and chemically. Spoilage of fish treated with PS in relation to the oxygen permeability (OP) of the polyethylene film was also examined. The trimethylamine (TMA) and formalin bound nitrogen compounds (FBN) formation at 0° in prepacked cod fillets is inhibited by the addition of HC and PS. A concentration of 0·4% of PS in the cod fillets is sufficient to inhibit the TMA production completely. The OP of the film determines the keeping quality of the cod fillets containing 0·4% of PS. The film with the lowest OP gives the best results, since the spoilage of PS treated fish during the first 12 days is exclusively caused by an increase of FBN. The formation of this fraction at 0° is related directly to the OP of the packing film. From the experiments with PS treated cod fillets it can be deduced that a film with a low OP gives the best results.