Physicochemical and microbiological characteristics of fresh Indian mackerel, spotted sardine and yellowtail scad, from Eritrea Red Sea waters

Abstract

Fresh small pelagic fish (Indian mackerel, spotted sardine and yellowtail scad) from the Eritrean waters of the Red Sea were investigated for their physicochemical properties (morphometric measurements, proximate composition, pH, salt, mineral content, color and oxidation indicators) and microbiological characteristics (total plate count; TPC, total coliforms; TC, E. coli, S. aureus, Salmonella spp.; V. parahaemolyticus, halophilic count and total fungal count; TFC). The morphometric measurements indicated that the yellow tail scad had the largest weight (47.6 g) and the smallest number of fish pieces (21) per kg. These small pelagic fish can be characterized as low-fat fish (3.26–3.85%) and a good protein source, with the highest protein content recorded in fresh Indian mackerel (21.29%). The ash and fiber content fell within the range of 1.57–1.77% and 0.24–0.38% respectively. The oxidation indicators (free-fatty acid, peroxide value, thiobarbituric acid, and p-anisidine value) were below the maximum allowable values in fresh fish. The fish were good sources of minerals (Ca, Mg, Fe and Zn), but the Indian mackerel exhibited the highest level of Cd content (0.04 mg/kg weight) which was still below the maximum permitted levels (0.25 mg/kg weight). The TPC, TC, E. coli, S. aureus, and halophilic count were below maximum allowable levels while Salmonella, V. parahaemolyticus and TFC were absent in the fresh fish samples.