Avaliação da Estabilidade Térmica de Histamina em Conservas de Pescado por CLAE

Abstract

Histamine [4-(2-aminoethyl) imidazole] is a biogenic amine and nonvolatile synthesized by decarboxylation of free L-histidine. The presence of bacterial histidine decarboxylase, high temperatures and manipulation in inadequate sanitary conditions, are factors that enable the biosynthesis of histamine. Histamine has an important feature for its heat resistance, once synthesized, cannot be degraded through the process of sterilization, cooking, freezing, or any other type of treatment that may suffer from post-capture. This amine can be present in fish and fermented products (e.g. wine, beer, cheese, etc.) however, fish is the main food involved. Ingestion of high concentrations of histamine may cause the appearance of symptoms such as nausea, headache, diarrhea, itching and flushing, especially in susceptible individuals. It should be noted that fish with high levels of histamine, in most of cases do not have sensory changes but there are reports of development of spicy or metallic flavor. The main goal of this survey was to assess the effect of thermal processing on degradation of histamine in fish. High Performance Liquid Chromatography (HPLC) was used as a method of detection and quantification of histamine. The extraction methodology was performed using methanol and for the detection of analyte present in the aliquot of the vial was derivatized with the reagent 6-aminoquinolyl-hydroxysuccinimidyl-N-carbamate (AQC). The analyzed samples showed concentrations of histamine in the range 1.05 to 2.94mg kg-1, in other words below the current legislation, which corresponds to 100mg kg-1. There was a reduction in the concentration of histamine in comparison to fresh and canned fish. This fact can be explained by the solubility of histamine in covering liquid and dipping of fillets. The samples were also submitted to bacterial count of histidine decarboxylase. The values of 4.60 and 1.80 log CFU g-1 correspond to a sample of hybrid fish fillet and tuna, respectively. Monitoring the levels of histamine aims to ratify the food safety for consumers. In addition, preventive measures and corrective action recommended by the system of Hazard Analysis and Critical Control Points (HACCP) must be taken in the fishing industry to provide harmless food.