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Physicochemical And Microbiological Parameters Associated With The Formation Of Histamine In Freeze Brine Of Commercial Yellowfin Tuna Fishing Boats

J.A.Gallegos-Infante, G.Barba-Quintero, G.Garcia-Tapia , R.F.Gon zalez-Laredo, N.E.Rocha-Guzman, J.A.Ramirez de Leon

Freeze brine used on board to freeze yellowfin tuna fishes is commonly used during several travels before being replaced. The aim of this work was to evaluate changes in the physicochemical and microbiological properties of freezing brine used in two fishing boats during two years, to determine the feasibility of forming histamine in the brine. Changes in pH, protein, chlorides, mesophilic and psycrophilic microorganisms and histamine level in freezing brine were determined. Changes in histamine and chlorides in yellowfin tuna muscle were evaluated too. In freezing brine the pH varied from 5.6 to 6.8, protein content increased near to 1.2%, chlorides varied from 15 to 18%. Maximum mesophilic and psycrophilic counts were 4.6 x 104 UFC/g and 4.5 x 105 UFC/g respectively. Freezing brine of the two fishing boats had a mean level of 19.68 (+/-13.51) ppm of histamine. In the flesh of the yellowfin tuna the value of chlorides varied from 0.86 to 1.57% and histamine mean level was 37.82 (+/-5.69) ppm. Results obtained indicated that halophilic microorganisms were able to grow in freezing brine. Histamine present in freezing brine was associated with growing of halophilic microorganisms.