The authors have declared that no competing interests exist.
Conceived and designed the experiments: KVD. Performed the experiments: KMN KVD. Analyzed the data: KVD. Contributed reagents/materials/analysis tools: Wrote the paper: KVD. Contributed the materials: KVD. Checked the manuscript: TTAK.
Estimation of nutrition profile of edible fishes is essential and thus a bio-monitoring study was carried out to find out the nutritional composition of commonly available fishes in Agatti Island water of Lakshadweep Sea. Protein, carbohydrate, lipid, ash, vitamin, amino acid and fatty acid composition in the muscle of ten edible fish species were studied. Proximate analysis revealed that the protein, carbohydrate, lipid and ash contents were high in
Fish is a major source of food for mankind, providing with a significant amount of the animal protein diet, excellent dietary sources of highly unsaturated fatty acid (HUFA) and polyunsaturated fatty acid (PUFA), especially the omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)
Extensive research has been done on fish lipids, fatty acids
Agatti Island lies in the Lakshadweep group of islands (latitude 10°48′–10°52′N; longitude 72°10′–72°12′E) in the Lakshadweep Sea of the Indian Ocean which is a part of Chagos - Maldives - Lakshadweep archipelago. Among the 425 atolls of the world, it is the largest atoll system with 12 atolls. This atoll system has grown up steeply from a depth about 1,500 to 4,000 m over the Chagos - Laccadive oceanic ridge. Lakshadweep consists of 36 islands covering an area of 32 sq. km of which 10 are inhabited. These islands lie scattered in the Lakshadweep Sea about 225 to 445 km from the main land coast. The islands are about 1–2 meters above the sea level. It has a total lagoon area of about 4, 200 sq. km, territorial water area of 20, 000 sq. km and an exclusive economic zone of 4, 00,000 sq. km
Ten marine fish species (
Folin - Ciocalteau Phenol method of Lowry et al.
Total carbohydrate was estimated by Phenol-Sulphuric acid method, described by Dubois et al.
Lipid content was estimated by the procedure given by Folch et al.
Fat soluble vitamins A, D3 and K and the water soluble vitamins B1, B2 and B6 were analysed in the HPLC (Merck - Hitachi L - 7400), following the method described by Sadasivam and Manickam
Powdered oven dried samples were extracted well and hydrolysed in 6 N HCl at 110°C for 24 h and the amino acids were estimated in the HPLC (Merck - Hitachi L - 7400) following the method of Baker and Han
For fatty acid analysis, each sample was oven dried at 67°C for 24 h and ground finely with mortar and pestle. The preparation and analysis of fatty acid methyl esters (FAMEs) from the fish tissues were performed according to the method described by Anon
Pearson Correlation Coefficient was employed for the better understanding of relationship between the percentage of protein, carbohydrate, lipid, ash, vitamins, amino acids and fatty acids with various fish species, using the statistical package of SPSS 16.0. One way ANOVA was also employed to understand the variation in the quantity of nutrients with respect to different species.
Total protein, total lipid, total carbohydrate and total ash contents of the muscle of ten fishes of Lakshadweep Sea are shown in
Species | Crude Protein(% dry weight) | Crude Carbohydrate(% dry weight) | Crude Lipid(% dry weight) | Crude Ash(% dry weight) |
|
11.54 | 4.56 | 3.55 | 1.05 |
|
11.51 | 3.92 | 4.21 | 1.51 |
|
13.26 | 3.68 | 4.56 | 1.39 |
|
10.58 | 2.97 | 4.78 | 1.28 |
|
12.53 | 4.23 | 3.11 | 1.11 |
|
13.69 | 5.56 | 2.96 | 1.57 |
|
10.58 | 6.12 | 5.56 | 1.56 |
|
10.54 | 4.16 | 5.28 | 1.19 |
|
11.67 | 5.91 | 4.54 | 1.65 |
|
10.51 | 5.68 | 6.97 | 1.14 |
Vitamins present in the fishes are shown in
Vitamins |
|
|
|
|
|
|
|
|
|
|
|
0.44 | 0.42 | 0.39 | 0.48 | 0.56 | 0.61 | 0.54 | 0.44 | 0.48 | 0.39 |
|
0.65 | 0.13 | 0.48 | 0.56 | 0.67 | 0.59 | 0.44 | 0.48 | 0.37 | 0.86 |
|
0.22 | 0.31 | 0.41 | 0.52 | 0.49 | 0.37 | 0.19 | 0.61 | 0.87 | 0.51 |
|
0.41 | 0.81 | 0.31 | 0.44 | 0.71 | 0.27 | 0.53 | 0.19 | 0.18 | 0.37 |
|
0.11 | 0.19 | 0.34 | 0.58 | 0.41 | 0.49 | 0.67 | 0.56 | 0.91 | 0.43 |
|
0.81 | 0.92 | 0.79 | 0.84 | 0.81 | 0.77 | 0.63 | 0.92 | 0.55 | 0.84 |
|
0.55 | 0.62 | 0.72 | 0.33 | 0.19 | 0.61 | 0.62 | 0.33 | 0.49 | 0.68 |
|
0.43 | 0.65 | 0.19 | 0.41 | 0.65 | 0.36 | 0.41 | 0.55 | 0.53 | 0.67 |
|
0.39 | 0.51 | 0.44 | 0.51 | 0.37 | 0.77 | 0.51 | 0.62 | 0.42 | 0.54 |
Amino acid composition in the muscle of ten fishes is shown in
Amino acid |
|
|
|
|
|
|
|
|
|
|
|
0.89 | 0.92 | 0.97 | 1.12 | 1.31 | 1.67 | 1.27 | 1.81 | 0.98 | 0.64 |
|
2.31 | 2.55 | 2.87 | 2.53 | 2.55 | 2.51 | 2.33 | 2.41 | 2.37 | 2.47 |
|
0.76 | 0.54 | 0.81 | 1.92 | 1.55 | 1.84 | 0.96 | 0.91 | 0.86 | 0.77 |
|
0.64 | 0.67 | 0.91 | 0.57 | 0.63 | 0.51 | 0.47 | 0.38 | 0.29 | 0.17 |
|
1.64 | 1.55 | 1.84 | 2.55 | 1.84 | 1.53 | 1.94 | 1.83 | 1.59 | 1.62 |
|
1.32 | 1.47 | 1.84 | 2.10 | 2.17 | 2.14 | 1.91 | 1.84 | 1.97 | 1.54 |
|
1.11 | 1.43 | 1.33 | 1.47 | 1.81 | 1.91 | 1.84 | 1.77 | 1.62 | 1.51 |
|
0.81 | 0.89 | 1.10 | 1.17 | 1.84 | 1.55 | 0.98 | 0.96 | 0.11 | 0.63 |
|
1.06 | 1.55 | 3.17 | 2.98 | 2.68 | 2.91 | 2.84 | 2.66 | 2.98 | 3.17 |
|
3.56 | 4.11 | 3.17 | 3.14 | 2.77 | 2.84 | 3.96 | 3.84 | 4.10 | 2.96 |
|
2.86 | 2.96 | 3.01 | 3.06 | 3.10 | 3.17 | 2.84 | 2.67 | 4.18 | 2.84 |
|
3.17 | 3.19 | 3.81 | 3.82 | 4.13 | 4.56 | 3.98 | 3.61 | 2.84 | 3.96 |
|
3.91 | 3.17 | 2.96 | 2.81 | 2.88 | 3.10 | 3.17 | 2.98 | 2.86 | 2.64 |
|
2.91 | 2.87 | 2.55 | 2.96 | 3.16 | 3.77 | 3.17 | 2.98 | 2.96 | 3.10 |
|
0.53 | 0.62 | 0.51 | 0.54 | 0.53 | 0.49 | 0.57 | 0.47 | 0.63 | 0.58 |
|
1.57 | 2.16 | 1.91 | 1.72 | 1.77 | 1.84 | 1.91 | 1.96 | 1.05 | 2.92 |
|
0.51 | 0.64 | 0.81 | 0.94 | 0.65 | 0.81 | 0.87 | 0.62 | 0.57 | 0.92 |
|
2.56 | 2.42 | 2.33 | 1.96 | 1.98 | 1.91 | 2.34 | 2.55 | 2.31 | 2.76 |
Fatty acids (%) |
|
|
|
|
|
|
|
|
|
|
|
||||||||||
|
0.21 | 1.77 | 0.26 | - | 0.41 | - | 0.66 | - | 0.73 | 0.81 |
|
1.98 | 0.84 | - | 0.61 | 0.53 | 0.13 | - | 0.11 | - | 0.61 |
|
0.46 | 0.49 | 0.43 | 0.54 | 0.52 | 1.18 | 1.64 | 1.17 | 1.59 | 1.67 |
|
0.11 | 0.39 | 0.11 | 0.16 | 0.10 | 1.64 | 1.51 | 1.79 | 1.83 | 1.54 |
|
8.64 | 10.66 | 10.64 | 10.28 | 10.64 | 8.31 | 7.26 | 8.65 | 7.11 | 8.21 |
|
0.99 | 1.07 | 1.04 | 1.21 | 1.01 | 2.11 | 2.10 | 2.63 | 2.68 | 2.15 |
|
16.96 | 15.69 | 13.97 | 14.16 | 15.92 | 15.0 | 16.10 | 15.81 | 15.83 | 15.21 |
|
2.55 | 0.51 | 0.64 | 0.53 | 0.53 | 0.68 | 0.54 | 0.51 | 0.67 | 0.59 |
|
0.41 | 0.43 | 0.36 | 0.62 | 0.42 | 0.33 | 0.41 | 0.48 | 0.68 | 0.58 |
|
2.84 | 0.77 | 0.33 | 1.12 | 0.71 | - | 1.11 | 1.61 | 1.57 | - |
|
0.13 | 2.51 | 0.31 | 0.17 | 2.11 | 1.58 | 1.79 | 1.81 | 1.14 | 1.61 |
|
1.11 | 0.64 | 2.21 | 1.19 | 0.20 | 2.61 | 2.34 | 2.55 | 3.11 | 3.61 |
|
0.53 | 0.53 | 0.28 | 2.14 | 1.16 | 2.11 | - | - | - | 1.19 |
|
1.21 | 0.54 | 0.51 | 2.55 | 0.17 | - | 0.67 | - | 0.68 | - |
|
0.84 | 0.81 | 0.54 | 0.61 | 2.84 | 0.81 | 0.84 | 0.67 | 0.89 | 0.91 |
|
38.97 | 37.65 | 31.63 | 35.89 | 37.27 | 36.49 | 36.97 | 38.79 | 38.51 | 38.69 |
|
||||||||||
|
0.07 | 0.17 | 0.16 | 0.51 | 0.40 | 0.11 | 0.61 | 0.67 | 0.53 | 0.57 |
|
0.11 | - | 0.81 | - | 0.43 | 0.18 | - | 0.16 | - | 0.63 |
|
0.33 | 0.11 | 0.61 | 0.64 | 0.11 | 0.67 | 1.10 | 1.11 | 1.63 | 1.59 |
|
- | 0.84 | 0.34 | - | - | 1.51 | 1.53 | 0.83 | 0.61 | 0.57 |
|
0.67 | 0.17 | - | 0.43 | 0.17 | 0.20 | 0.21 | 0.17 | 0.62 | 0.51 |
|
0.58 | - | 0.51 | 0.32 | - | 0.11 | 0.16 | 0.71 | 0.78 | 0.69 |
|
- | 0.63 | 0.12 | 0.11 | 0.91 | 0.59 | 0.81 | 0.76 | 0.77 | 0.12 |
|
5.32 | 4.41 | 5.62 | 6.73 | 6.84 | 4.31 | 3.65 | 4.69 | 4.29 | 4.65 |
|
0.11 | - | 0.22 | - | 0.63 | 1.10 | - | 1.17 | - | 1.10 |
|
1.21 | 0.51 | 0.14 | 0.84 | - | - | - | - | - | - |
|
0.89 | 0.63 | - | 0.61 | 0.81 | 0.57 | - | 0.63 | 0.57 | - |
|
0.77 | 0.17 | 0.51 | 0.57 | 0.92 | 0.61 | 0.63 | 0.17 | 0.78 | 0.77 |
|
2.11 | 1.74 | 2.16 | 1.75 | 2.17 | 0.81 | 0.83 | 0.63 | 0.55 | 0.59 |
|
6.40 | 5.31 | 5.88 | 5.57 | 6.15 | 5.40 | 6.15 | 6.88 | 6.57 | 5.15 |
|
0.68 | - | - | - | 0.16 | 1.11 | 1.05 | 1.17 | 0.87 | 0.53 |
|
0.57 | 0.84 | - | 0.64 | 0.53 | 0.58 | 0.58 | 0.83 | - | 0.89 |
|
0.63 | - | 0.62 | - | - | - | 1.11 | - | 0.29 | 0.71 |
|
- | 0.77 | - | - | - | 1.10 | 1.74 | 0.54 | 0.41 | - |
|
0.11 | - | - | 0.52 | 0.41 | 0.33 | 0.21 | - | - | 0.23 |
|
- | 0.63 | 0.51 | - | 0.52 | 0.82 | 0.16 | 0.91 | 0.98 | 0.67 |
|
0.11 | 0.12 | 1.69 | 0.62 | 0.53 | 0.63 | 0.67 | 0.51 | 0.58 | 0.58 |
|
0.52 | 2.0 | 1.61 | 1.77 | 2.52 | 1.11 | 1.21 | 1.27 | 1.11 | 1.61 |
|
0.17 | 1.0 | 1.62 | 0.53 | 1.11 | 1.63 | 1.14 | 0.55 | 0.54 | 0.64 |
|
0.63 | 0.69 | 0.18 | 1.64 | 0.98 | 0.51 | 0.63 | 0.57 | 0.63 | 0.59 |
|
21.99 | 22.42 | 23.31 | 23.38 | 26.30 | 23.99 | 24.18 | 24.93 | 23.11 | 23.39 |
|
||||||||||
|
0.18 | - | 0.14 | 1.67 | 0.62 | 0.11 | 0.62 | 0.57 | 0.16 | 0.12 |
|
0.22 | 0.63 | 0.18 | 2.62 | 2.11 | 0.19 | 0.86 | 0.81 | 0.84 | 0.67 |
|
8.89 | 6.93 | 9.16 | 2.40 | 2.83 | 0.91 | 0.81 | 0.72 | 0.81 | 0.92 |
|
1.0 | 1.0 | 1.53 | 1.11 | 1.58 | 5.62 | 4.91 | 3.11 | 4.98 | 4.96 |
|
1.65 | 1.32 | 1.41 | 1.61 | 1.62 | 2.11 | 2.16 | 2.92 | 2.67 | 2.72 |
|
1.62 | 1.43 | 1.63 | 1.82 | 1.91 | 1.41 | 1.43 | 1.01 | 1.63 | 1.57 |
|
- | 1.12 | - | 0.58 | 0.63 | 0.63 | 0.57 | 0.51 | 0.58 | 0.41 |
|
1.13 | 1.62 | 1.63 | 1.01 | 0.41 | 1.12 | 1.51 | 1.59 | 1.63 | 1.71 |
|
2.0 | 1.61 | 1.77 | 1.81 | 1.73 | 2.61 | 1.92 | 2.13 | 2.47 | 2.15 |
|
1.68 | 1.98 | 1.11 | 1.32 | 1.57 | 0.16 | 0.17 | 0.18 | 0.51 | 0.66 |
|
4.1 | 3.3 | 3.9 | 4.0 | 4.41 | 3.90 | 4.10 | 5.11 | 5.17 | 4.81 |
|
2.13 | 1.98 | 1.63 | 1.13 | 1.19 | 1.13 | 1.11 | 1.52 | 1.63 | 1.57 |
|
1.11 | 3.0 | 2.11 | 1.63 | 1.81 | 1.57 | 1.63 | 1.67 | 1.77 | 1.57 |
|
2.0 | 2.1 | 3.2 | 3.0 | 4.92 | 2.11 | 2.17 | 2.63 | 2.13 | 2.60 |
|
2.1 | 1.8 | 2.61 | 2.63 | 1.28 | 2.77 | 3.11 | 3.17 | 3.98 | 3.97 |
|
2.9 | 2.7 | 3.1 | 2.0 | 2.6 | 4.81 | 4.63 | 2.67 | 2.77 | 2.60 |
|
32.71 | 32.52 | 35.11 | 30.34 | 31.22 | 31.96 | 31.51 | 30.32 | 33.73 | 33.01 |
|
13.05 | 13.86 | 15.06 | 15.81 | 15.7 | 20.27 | 20.67 | 17.55 | 21.14 | 20.15 |
|
8.94 | 9.29 | 9.34 | 8.27 | 9.82 | 7.13 | 6.88 | 8.05 | 8.37 | 8.69 |
|
1.46 | 1.49 | 1.61 | 1.91 | 1.60 | 2.84 | 3.00 | 2.18 | 2.53 | 2.32 |
|
0.69 | 0.67 | 0.62 | 0.52 | 0.63 | 0.35 | 0.33 | 0.46 | 0.40 | 0.43 |
|
||||||||||
|
0.10 | - | 0.61 | 0.53 | - | 0.15 | - | - | - | 0.61 |
|
- | 0.11 | 0.57 | 0.41 | 0.17 | 0.16 | 0.16 | 0.11 | - | 0.11 |
|
0.17 | 0.18 | 0.16 | 0.18 | - | 0.53 | 0.14 | - | - | - |
|
0.18 | 0.63 | 0.57 | 0.43 | 0.18 | - | 0.11 | 0.12 | 0.16 | 0.12 |
|
0.21 | 0.20 | 0.21 | 0.23 | 0.16 | 0.61 | 0.52 | - | - | 0.11 |
|
0.18 | 0.17 | 0.62 | 0.51 | 0.15 | 0.53 | 0.48 | 0.22 | 0.18 | 0.17 |
|
0.63 | - | 0.53 | 0.47 | - | 0.17 | 0.22 | 0.16 | 0.15 | 0.14 |
|
0.18 | 0.62 | 0.81 | 0.56 | 0.16 | 0.19 | 0.17 | - | 0.14 | - |
|
0.57 | - | 0.62 | 0.49 | 0.11 | 0.54 | 0.33 | 0.18 | - | 0.15 |
|
- | 0.61 | 0.77 | 0.61 | 0.10 | 0.11 | 0.16 | 0.14 | 0.61 | - |
|
0.11 | 0.57 | 0.81 | 0.71 | - | 0.17 | 0.18 | 0.27 | 0.15 | 0.13 |
|
- | 0.11 | - | 0.11 | 0.61 | 0.10 | 0.17 | - | 0.36 | - |
|
0.11 | 0.80 | - | 0.21 | - | 0.11 | 0.16 | 0.48 | - | 0.51 |
|
- | 0.15 | 0.16 | 0.15 | 0.11 | 0.12 | 0.77 | 0.71 | 0.11 | 0.16 |
|
0.17 | 0.14 | 0.17 | 0.11 | 0.16 | 0.17 | 0.63 | 0.53 | 0.15 | - |
|
0.13 | 0.11 | 0.14 | - | 0.13 | 0.22 | 0.44 | 0.11 | 0.18 | 0.18 |
|
0.11 | 0.16 | - | 0.17 | 0.14 | - | 0.11 | - | - | 0.14 |
|
0.17 | - | 0.16 | 0.90 | 0.17 | 0.10 | 0.51 | 0.16 | 0.18 | 0.13 |
|
0.13 | 0.51 | 0.17 | 0.39 | - | - | - | 0.11 | 0.11 | 0.11 |
|
0.69 | 0.57 | 0.84 | 0.62 | 0.56 | 0.17 | 0.65 | 0.36 | 0.38 | 0.23 |
|
3.85 | 5.64 | 7.72 | 7.79 | 2.91 | 5.55 | 5.91 | 3.66 | 2.86 | 3.00 |
|
2.48 | 1.71 | 2.23 | 2.6 | 2.3 | 2.81 | 2.01 | 2.30 | 1.83 | 1.91 |
The dominant PUFA was linoleic acid (C18:2 ω-6) in
Ratio of ω-6/ω-3 PUFAs (0.33–0.69%) found in the present study was lower than the value (4.0 at maximum) recommended by the UK Department of Health
Percentages of fatty acids identified differed among species and organs. In red muscle and liver, lipids undergo more enzymatic activities than in smooth muscle, producing large amounts of free fatty acids in oils
Present study was carried out to find out the nutritional quality of ten economically valuable fishes of the Lakshadweep archipelago. Results showed that these fishes are a source of high quality protein, carbohydrate, lipid, ash, vitamins, with a well balanced composition of essential amino acids and fatty acids. The ω-3 and ω-6 PUFAs values were also higher in these fishes. Hence, consumption of these species is highly recommended since these fishes are more nutritious. Further, through this bio-monitoring study, present results of the proximate composition analysis, amino acid and fatty acid analysis can be used as baseline data for comparisons in future, with regard to fish nutritional quality.
The authors are thankful to the authorities of Annamalai University for the facilities. We are thankful to Prof. L. Kannan for critically going through the manuscript and special thanks go to Mr. M. Gopi, Mr. S. Prakash, Mr. T. Marudhupandi and Mr. Aboobacker Koya for their timely help in sample collection. We also thankfully acknowledge the valuable comments obtained from three anonymous reviewers, which greatly improved the manuscript.