ABSTRACT
Chemical composition viz., fatty acids, amino acids and minerals of yellowfin tuna (Thunnus albacares) eye were analyzed for better utilization of fish processing discards. Analysis of fatty acids composition by gas chromatography-mass spectrometry revealed the presence of polyunsaturated fatty acids namely docosahexaenoic acid, eicosapentaenoic acid, arachidonic acid and linoleic acid at the levels of 37.8, 7.1, 3.6 and 1.4%, respectively. The major available monounsaturated fatty acids, palmitoleic acid and oleic acid were present at the level of 17.9 and 18.3% respectively. Myristic acid was the dominant saturated fatty acid and occupied 2% of the total fatty acids. Amino acid analysis by high-performance liquid chromatography showed that the tuna eye has a high concentration of glycine (19.24 mg/100 g) followed by glutamic acid (16 mg/100 g) and aspartic acid (12.76 mg/100 g). Analysis of mineral content of tuna eye showed the presence of higher sodium and lower copper content. The results revealed that yellowfin tuna eye could be used as a potential source of ω-3 fatty acids and essential amino acids.
ABSTRACT
Processing discards from tiger tooth croaker, such as head, viscera, and swim bladder, were analyzed for proximate, biochemical, fatty acid, and mineral composition. The proximate analysis showed high protein content (21.04%) in the swim bladder and high fat content (4.10%) and ash content (2.26%) in the head. The biochemical quality indices such as non-protein nitrogen, total volatile base, trimethylamine, free fatty acids, peroxide value, and thiobarbituric acid reactive substances in the viscera were higher than those in the head and swim bladder. Gas chromatographymass spectrometry analysis of fatty acids composition showed high polyunsaturated fatty acids in the head (58.82%), followed by the viscera (45.80%) and the swim bladder (35.57%). The major available saturated fatty acid, i.e., palmitic acid, was higher in the swim bladder (30.49%). Mineral and heavy metals analyzed via inductively coupled plasma-optical emission spectrometer showed high calcium, sodium, and magnesium contents in the head region (346.80, 62.55, and 14.89 mg/kg respectively). Heavy metal levels were within the permissible limit.
