HISTAMINE LEVELS AND HISTAMINE PRODUCING BACTERIA IN FOUR SELECTED FISH SPECIES DISPLAYED IN THREE FISH MARKETS WITHIN TRIPOLI-CITY LIBYA

Abstract

The study aimed to assess temperature, histamine level and histamine producing bacteria (HPB) in four species of fresh fish samples i.e, Sardinellaaurita, Boopsboops, Trachurusmediterraneus and Scomberscombrus that are collected from three markets (A, B, C) within Tripoli city Libya. The results revealed that 95% of the fish samples had a temperature range between 5-220C, while 5% had a temperature < 50 C. Histamine was recorded in 43% of the samples. The ranges of histamine in sardine, bouge, saury, and mackerel samples were 1.29-5.74; 1.34-29.74;1.31-7.57 and 1.39-2.49 mg/100 g meat, respectively. These levels did not exceed the maximum limit (10 mg/100) adopted by the Libyan authority, except one sample (29.74 mg/100 g meat). A significant difference (P<0.05) in histamine levels was observed among the three markets. However, a nonsignificant difference (P>0.05) was observed between the fish species. The range for the means of HPBC in sardine, bouge, saury, and mackerel samples were 1.8x104-5.4x104; 6.4x104-2.0x105;6.4x104-6.9105; 1.6x104- 4.1x105cfu/g fish meat, respectively. Most of the HPB isolates were belonged to the family Enterobacteriaceae and some belong to the family Vibrionaceae. Vibrio fluvialis recorded the highest prevalence percentage (18%) followed by Erwiniaspp, S. putrrefacienes, and K. planticola, i.e.,12.2, 11.9 and 10.0%, respectively. The results of this study reflect the poor cooling conditions of the samples and poor cooling techniques practiced in these markets. Therefore, the hygienic practices in these markets have to be improved, and preferably the HACCP system has to be implemented.