Assessment of Temperature and Microbiological Quality of Fresh Sardine, Bouge, Saury and Mackerel Marketed in Tripoli City, Libya

The aim of this study was to assess thetemperature, total aerobic plate count (TAPC), and histamine-producingbacterial count (HPBC) of four types of fish, viz., sardines (Sardinellaaurita), bouge (Boops boops), saury (Trachurus mediterraneus), and mackerel(Scomber scombrus), that are sold in three major fish markets in Tripoli’s citycenter. A total of 113 samples of these fish types were collected, both in themorning and in the evening, from July to December in the fishing season.Results showed that the temperature of the collected fish samples ranged from<5°C to 22°C. Of the total 113 fish samples, 5.0%, 52.0%, and 43.0% hadtemperatures of <5°C, 5°C–14°C, and 15°C–22°C, respectively. The TAPC of allthe fish samples ranged from 3.0 × 103 to 3.5 × 107 colony-formingunit/g(cfu/g) of meat (with skin), with a mean of 1.1 × 106 cfu/g. The HPBCranged from an estimated 5.0 × 102 to 2.7 × 106 cfu/g, with a mean of 1.8 × 105cfu/g. Statistical analysis of the data showed a weak correlation (r = 0.05)between TAPC and HPBC of all the fish samples collected from the three majormarkets. The TAPC results revealed that 50%, 46%, 38%, and 17% of the saury,bouge, mackerel, and sardine fish samples, respectively, did not comply withthe standard specification limit (106 cfu/g) prescribed by the Libyanauthorities. A total of 26 isolates of histamine-producing bacteria wereidentified in this study. The majority of them belonged to the Enterobacteriaceaefamily and were not indigenous to the marine environment. There was a variationin the distribution of these bacterial isolates among all the fish samplesduring the course of the study. However, Vibrio fluvialis, Erwinia spp., andKlebsiella planticola were detected in all the fish samples throughout thestudy period. The high TAPC and HPBC recorded in this study could be attributedto cross-contamination due to the poor quality of the surrounding environmentand the poor hygienic practices. Therefore, there is an urgent need for propercontrol of product handling conditions in the fish markets monitored in thisstudy.