Evaluation of Freshness of Some Imported Marine Fish Species Retailed for Sale in Al Beida City, Libya

A total of 100 random samples of marine water fish represented by Barboni, Morgan, Mackerel and Balameta (25 of each) were collected from local markets at Al Beida City, Libya. Samples were evaluated for their freshness through determination of proteolytic and lipolytic indices. The obtained results revealed that mean values of pH were 6.11±0.05, 6.17 ± 0.03, 6.15 ± 0.04 and 6.25 ±0.7 for Barboni, Morgan, Mackerel and Balameta, respectively. Also, it was found that the mean of TVN values was 22.29 ± 0.26, 23.27 ± 0.24, 27.38 ± 0.33 and 24.19 ±0.23 for Barboni, Morgan, Mackerel and Balameta fish samples, respectively. Also, Trimethylamine (TMA) as proteolytic index of spoilage was determined and it was found that the mean of TMA values was 5.22 ± 0.23, 4.18 ± 0.18, 3.32 ± 0.33 and 4.90 ±0.49 mg %for Barboni, Morgan, Mackerel and Balameta fish samples, respectively. In addition, Thiobarbituric Acid (TBA) as lipolytic index of spoilage was estimated and it was recorded that the mean of TBA values was 3.9± 0.13, 3.6 ± 0.12, 3.8 ± 0.14 and 4.1 ±0.11 mg % for Barboni, Morgan, Mackerel and Balameta fish samples, respectively. Finally, it was found that the mean of peroxide values was 0.47 ± 0.06, 0.41 ± 0.05, 0.43 ± 0.04, 0.48 ±0.06 meq O2/kg for Barboni, Morgan, Mackerel and Balameta fish samples, respectively. Luckily, it was noticed that all of the examined samples of fish are accepted according to permissible limits stipulated by Egyptian Organization for Standardization, (2005).