NUTRITIONAL COMPOSITION OF MUSCLE IN CULTURED SINIBOTIA REEVESAE POPULATION AT DIFFERENT AGES

Sinibotia reevesae, an endemic fish, live only in the upper reaches of the Yangtze River. To study nutritional composition in muscle during different growth phases, the main nutrient components in the muscles of age 1, 2 and 3 farmed (fed formulated feed) S. reevesae were analyzed, and the nutritional value and product flavor were evaluated. The general nutrient compositions were determined by routine methods, the amino acid compositions were measured with an amino acid analyzer and the fatty acid compositions by gas chromatography-mass spectrometry (GC-MS). The results showed that the contents of crude protein and crude fat in S. reevesae muscles increased with fish growth. With the increase of age, the moisture content decreased, whereas the contents of crude protein and crude fat increased. The crude protein in muscles of age-group 3 was significantly higher than that of the other two groups (P<0.05), while no significant difference was found in crude protein content between age-group 2 and 3 (P>0.05). The contents of different amino acids in muscles ofS. reevesae among 3 groups were stable. Glutamic acid, aspartic acid and lysine were the most abundant among 16 kinds of amino acids detected in muscles of each group. The essential amino acid index (EAAI) and the ratio of branched chain amino acid to aromatic amino acid (F value) of S. reevesae were very high. According to nutrition evaluation in amino acid score (AAS) and chemical score (CS), the first limiting amino acid for muscles of S. reevesae during different growth phases was valine acid. Totally 7 saturated fatty acids (SFA), 6 mono-unsaturated fatty acids (MUFA), and 7 poly-unsaturated fatty acids (PUFA) were found in dry muscles of S. reevesae from each group. The content of SFA was significantly lower than that of unsaturated fatty acids (UFA) (P<0.05), and the total content of MUFA, especially C_18:1n9c, was significantly higher among UFA. PUFA in age-group 2 was significantly higher than that of the other two groups (P<0.05). The total content of EPA and DHA was lower than other Cobitidae fishes with the tendency to descend with the increasing age. These results indicate thatS. reevesae is a kind of high nutritional value, delicious, and high quality fish, and that S. reevesae in age 2 and 3 age are great for consume because of higher contents of crude protein and crude fat, better amino acid and fatty acid compositions in muscle.