Table 1.
Free amino acid content of raw and canned European eels packed in sunflower oil throughout the different steps of the canning process and after 2 and 12 months of storage (expressed mg/100 g muscle).
| Raw | Frying | Sterilization | Storage 2 Months | Storage 12 Months | |
|---|---|---|---|---|---|
| NON-ESSENTIAL AMINO ACIDS | |||||
| Aspartic acid | 14.24 ± 0.54 a | 11.23 ± 2.60 a | 26.34 ± 1.39 b,c | 28.22 ± 0.39 c | 23.64 ± 1.93 b |
| Glutamic acid | 21.60 ± 1.75 a,b | 23.11 ± 1.07 a | 15.90 ± 0.45 c | 20.37 ± 0.84 a,b | 19.92 ± 1.09 b |
| Hydroxyproline | 0.86 ± 0.04 a,b | 1.02 ± 0.01 a | 0.79 ± 0.03 b | 1.33 ± 0.14 c | 2.13 ± 0.09 d |
| Serine | 3.81 ± 0.03 a | 4.67 ± 0.12 b | 2.83 ± 0.45 c | 1.62 ± 0.02 d | 3.04 ± 0.44 c |
| Glycine | 50.24 ± 2.29 a | 57.10 ± 2.40 a | 39.89 ± 2.22 b | 56.12 ± 5.78 a | 42.30 ± 4.88 b |
| Arginine | 80.58 ± 6.07 a | 76.44 ± 2.02 a | 128.16 ± 0.22 b | 140.34 ± 5.90 c | 159.91 ± 8.90 d |
| Alanine | 12.37 ± 1.13 a | 12.20 ± 0.50 a | 13.54 ± 1.98 a | 15.72 ± 3.65 a | 22.40 ± 1.77 b |
| Proline | 2.68 ± 0.28 a | 4.77 ± 0.26 b | 5.20 ± 0.18 b | 6.66 ± 1.23 c | 8.09 ± 0.71 d |
| Tyrosine | 5.98 ± 0.32 a | 8.97 ± 0.33 b | 9.37 ± 0.19 b | 10.25 ± 1.62 b | 12.21 ± 1.03 c |
| Taurine | 91.63 ± 6.62 a | 169.73 ± 0.57 b | 65.08 ± 2.93 c | 76.21 ± 7.04 c | 75.57 ± 6.88 c |
| Ornithine | 1.58 ± 0.08 a | 0.27 ± 0.02 b | 0.33 ± 0.13 b,c | 0.48 ± 0.01 c,d | 0.59 ± 0.15 d |
| Total non-essential amino acids (NEAA) | 286.31 ± 19.25 a | 370.75 ± 4.48 b | 283.79 ± 20.01 a | 357.31 ± 25.58 b | 368.43 ± 20.47 b |
| ESSENTIAL AMINO ACIDS | |||||
| Histidine | 222.76 ± 6.99 a | 333.86 ± 3.11 b | 221.74 ± 1.69 a | 240.24 ± 5.10 a | 280.36 ± 22.41 c |
| Threonine | 9.07 ± 0.06 a | 11.47 ± 0.96 a,b | 11.92 ± 0.71 a,b | 13.50 ± 0.26 b,c | 16.14 ± 2.23 c |
| Valine | 1.73 ± 0.15 a | 4.49 ± 0.18 b | 7.48 ± 0.35 c | 6.05 ± 0.10 d | 8.17 ± 1.09 c |
| Isoleucine | 2.47 ± 0.32 a | 3.53 ± 0.54 a,b | 4.66 ± 0.14 b,c | 4.48 ± 1.30 b,c | 5.27 ± 0.73 c |
| Leucine | 4.08 ± 0.32 a | 5.26 ± 1.52 a | 7.60 ± 0.25 b | 5.03 ± 0.05 a | 10.57 ± 0.74 c |
| Phenylalanine | 4.36 ± 1.23 a,b | 4.17 ± 0.18 a | 5.42 ± 0.08 a,b,c | 5.57 ± 0.53 b,c | 6.10 ± 0.67 c |
| Lysine | 4.48 ± 0.52 a | 15.80 ± 0.50 b | 16.39 ± 1.76 b | 15.96 ± 0.46 b | 29.67 ± 0.47 c |
| Tryptophan | 5.24 ± 0.17 a | 5.81 ± 0.14 a | 7.06 ± 0.35 b | 7.16 ± 1.00 b | 8.33 ± 0.25 c |
| Total essential amino acids (EAA) | 255.53 ± 6.59 a | 379.98 ± 2.13 b | 274.57± 13.05 a | 299.49 ± 2.08 a | 346.72 ± 34.79 b |
| EAA/NEAA ratio | 0.90 ± 0.08 a,b | 1.02 ± 0.01 a | 0.95 ± 0.04 a,b | 0.84 ± 0.07 b | 0.94 ± 0.06 a,b |
| Total free amino acids | 541.83 ± 12.66 a | 750.73 ± 6.30 b | 563.84 ± 37.95 a | 656.80 ± 23.50 c | 743.10 ± 26.87 b,c |
a–d Mean values of at least three determinations ± standard deviation with different superscripts in the same row were significantly different (p < 0.05).