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

Özet

The aim of this study was to assess the temperature, total aerobic plate count (TAPC), and histamine-producing bacterial count (HPBC) of four types of fish, viz., sardines (Sardinella aurita), bouge (Boops boops), saury (Trachurus mediterraneus), and mackerel (Scomber scombrus), that are sold in three major fish markets in Tripoli’s city center. A total of 113 samples of these fish types were collected, both in the morning 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% had temperatures of <5°C, 5°C–14°C, and 15°C–22°C, respectively. The TAPC of all the fish samples ranged from 3.0 × 103 to 3.5 × 107 colony-forming unit/g(cfu/g) of meat (with skin), with a mean of 1.1 × 106 cfu/g. The HPBC ranged from an estimated 5.0 × 102 to 2.7 × 106 cfu/g, with a mean of 1.8 × 105 cfu/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 major markets. The TAPC results revealed that 50%, 46%, 38%, and 17% of the saury, bouge, mackerel, and sardine fish samples, respectively, did not comply with the standard specification limit (106 cfu/g) prescribed by the Libyan authorities. A total of 26 isolates of histamine-producing bacteria were identified in this study. The majority of them belonged to the Enterobacteriaceae family and were not indigenous to the marine environment. There was a variation in the distribution of these bacterial isolates among all the fish samples during the course of the study. However, Vibrio fluvialis, Erwinia spp., and Klebsiella planticola were detected in all the fish samples throughout the study period. The high TAPC and HPBC recorded in this study could be attributed to cross-contamination due to the poor quality of the surrounding environment and the poor hygienic practices. Therefore, there is an urgent need for proper control of product handling conditions in the fish markets monitored in this study.