Comparative Analysis on Muscle Nutrient Composition of Culter alburnus at Different Growth Stages

In order to evaluate the muscle nutrition quality of Culter alburnus at different growth stages, the general nutrition including proximate nutrient, texture, mineral element, amino acid and fatty acid composition were determined. The results showed that there were no significant difference in the mositure, crude protein, crude ash content among three groups (P>0.05). Besides, the content of crude fat in the muscle of C. alburnus in 0.5 kg group and 1 kg group were significant higher than that in 0.2 kg group, with growth rates of 38.12% and 53.96% , respectively (P<0.05). The hardness, springiness and chewiness of muscle in C. alburnus significantly increased during the development stage (P<0.05), while the same trend was true for K, Ca, Mg and Na content (P<0.05), and the highest was found in 1 kg group. The content of total amino acids (TAA), essential amino acids (EAA), nonessential amino acids (NEAA), delicious amino acids (DAA) and branched-chain amino acids (BCAA) in 1 kg group was significantly higher than those in 0.2 kg groups (P<0.05). According to amino acid score (ASS) and chemical score (CS), the first limiting amino acids were Met + Cys in C. alburnus, and the highest essential amino acid indices (EAAI) was found in 1 kg group, which was 68.81. The muscle contained 28 kinds of fatty acids, the EPA fatty acid content in 0.5 kg group and 1 kg group were significantly lower than in 0.2 kg group, with a reduction of 65.52% and 57.38%, repectively, and a reduction of 70.43% and 60.51% for DHA, repectively (P<0.05). Therefore, it was recommended that additional EPA and DHA could be supplemented in the feed of C. alburnus to improve the nutritional value of cultured fish. The results showed that Culter alburnus had rich nutrition, and 1 kg groups had better edible value.