HISTAMINE DETERMINED BY FLUOROMETRY, IN FISH ME AL AND THE ROW MATERIAL SUBJECTED TO DIFFERENT TEMPERATURES.

Abstract

A fluorometric method was optimized in order to determine the concentration of histamine in físh meal, this method ineludes methanol extraction, ionic exchange purification and fluorescence reaction with ophtaldialdehyde. A lineal behaviour was found for histamine concentrations ranging from 0.1 to 15 ug/5mL and an excellent selectivity for histamine in the presence of other biogenic amines. On the other hand the recovery, from the ion exchange resin, was evaluated, through the employment of standard Solutions of biogenic amines and mackerel Trachurus symmetricus murphyi, (Nichols, 1920) meal samples, quantified in the fluorometer after been eluted from the resin. Recoveries of the order of 100% were obtained for concentrations Solutions of histamine lower than 350 mg/Kg, and from 85 to 90% recovery for higher concentrations Solutions. Then samples of fish meal were analyzed, for histamine concentration and the results compared to those found by certificaron laboratorios, in order to evalúate the correlation found between the respective valúes. The correlation results showed no significant differences (p=0.05), but nevertheless, the valúes found by the fluorometric method, were slightly lower than those of HPLC, this could be due to retention of histamine by the resin in the purification step. The fluorometric method was finally applied to thestudy of the effect of storage temperature, on the row material, previous to meal reduction, measured by the determinaron of the biogenic amine, several times for a period of 3 days in mackerel, kept at different temperaturas.