Table 5.
Nutritional quality of protein of gilthead sea bream by-products.
| Amino Acids | FAO/WHO/UNU * | By-Product | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Muscle | Fishbone | Gills | Guts | Head | Liver | Skin | SEM | Sig. | ||
| Histidine | 1.5 | 178.21 bc | 229.84 e | 165.32 abc | 130.30 a | 200.32 cd | 165.91 abc | 153.53 ab | 5.90 | *** |
| Isoleucine | 3.0 | 127.25 bc | 136.34 c | 90.43 a | 92.97 a | 100.19 ab | 132.58 bc | 103.99 abc | 3.84 | *** |
| Leucine | 5.9 | 103.68 abc | 114.33 c | 82.30 a | 76.30 a | 86.31 ab | 111.54 bc | 88.64 abc | 3.04 | ** |
| Lysine | 4.5 | 180.43 c | 182.97 c | 127.02 ab | 82.22 a | 140.46 bc | 99.10 ab | 148.38 bc | 6.21 | *** |
| Methionine | 1.6 | 103.10 b | 91.69 b | nd a | nd a | 86.22 b | 72.54 b | 72.06 b | 5.68 | *** |
| Phe + Lys | 3.8 | 165.95 ab | 183.45 b | 127.73 a | 128.31 a | 148.61 ab | 166.79 ab | 135.28 a | 4.43 | *** |
| Threonine | 2.3 | 172.66 abc | 204.10 c | 196.41 c | 144.12 ab | 182.80 bc | 132.77 a | 150.79 ab | 5.17 | ** |
| Valine | 3.9 | 111.71 ab | 126.10 bc | 100.74 ab | 102.51 ab | 102.50 ab | 143.68 c | 96.04 a | 3.13 | ** |
| IEAA | 138.99 bc | 151.67 c | 66.73 a | 58.63 a | 123.51 bc | 124.02 bc | 114.22 b | 4.82 | *** | |
a–e Means in the same row with different letters differ significantly (p < 0.05; Duncan test). SEM: standard error of the mean. Sig.: significance; **: p < 0.01, ***: p < 0.001. Phe + Tyr: phenylalanine + tyrosine; IEAA: essential amino acid index; pattern proteins are expressed in (g/100 g protein); nd: not detected. Values of CS and IEAA are from the FAO/WHO/UNU [28] protein pattern *.