AN IMPROVED HISTAMINE ASSAY IN FISH BY US ING AN OXYGEN SENSOR AND ITS COMPARISON WITH THE AOAC METHOD

A modified extraction method for determination of histamine in fish by using an oxygen sensor was examined. Histamine in canned and raw tuna was extracted with methanol, then the solution was evaporated and the residue was dissolved in phosphate buffer (0.1 M, pH 7.6). There was a high correlation between histamine contents determined by the oxygen sensor and the AOAC methods. To simplify the procedure, histamine in canned tuna was extracted by adding phosphate buffer and heating at 10 0 degrees C in a water bath for 15 min. There was a high correlation b etween the contents of histamine extracted with phosphate buffer and d etermined by the oxygen sensor method and those of histamine extracted with methanol and determined by the AOAC method. This heating extract ion procedure in buffer is simple, rapid and practical for consecutive assay of many samples.