Proximate Composition of Some Selected Marine Fishes

Abstract

Knowledge of the proximate composition of fishery species is fundamentally important for the application of different technological processes, the characterization of species after death, assessment of raw-material quality, and obtaining an indication of the sexual stage. Eleven marine fish species—Johnius argentatus, Harpodon nehereus, Cynoglossus lingua, Johnius elongatus, Sillaginopsis panijus, Pomadasys hasta, Setipinna phasa, Megalaspis cordyla, Rita rita, Gonialosa manmina, and Scatophagus argus—available at the local fish markets in Khulna City were considered in this study to determine their proximate composition. The proximate composition of the fish, including protein, lipid, moisture, and ash, was determined under different conditions: raw fish (whole body), different body parts (head, middle, and tail), and differently processed fish (boiled and fried). In the whole body, protein, lipid, moisture, and ash contents were highest in G. manmina, S. argus, H. nehereus, and S. argus, respectively, while the lowest values were found in H. nehereus, C. lingua, M. cordyla, and R. rita, respectively. Among the different body parts, the head contained the highest amount of protein, followed by the middle and tail parts, whereas widely dissimilar patterns were observed for lipid, moisture, and ash contents. Wide variations in protein content, ranging from 13.88% to 33.6%, were observed among species and cooking methods. Fat content varied among species, ranging from 0.39% to 4.1% in raw fish, 0.8% to 3.37% in boiled fish, and 15.8% to 33.9% in fried fish. Frying resulted in a considerable increase in fat content compared with raw fish (15.8–33.9% versus 0.39–4.1%). Moisture content was much higher in raw fish (71.94–84.85%) and boiled fish (71–83%) than in fried fish (28.6–53.3%). The highest ash content was found in fried S. phasa (9.1%).

The present study is comprehensive in nature and can be used as a reference for feed formulation and for determining the health and nutritional status of commercially reared species.