Supplementation of sodium chloride in diets to improve the meat quality of Pacific white shrimp, Litopenaeus vannamei, reared in low-salinity water

To investigate the effect of dietary sodium chloride (NaCl) on meat quality of white shrimp (Litopenaeus vannamei) reared in low-salinity (2gL-1) water, shrimp were distributed into four groups (treatments T-1, T-2, T-3 and control) with three replicates. All shrimps were completely randomised stocked into 12 tanks at an initial density of 40 shrimps per tank. Diets for the control, T-1, T-2 and T-3 groups consisted of the basal diet supplemented with 0gkg-1, 10gkg-1, 20gkg-1 and 40gkg-1 of NaCl respectively. After 50days, shrimps in T-3 showed significantly better (P<0.05) moisture, crude protein and ash than those of the control and T-1. Higher muscle Na content was observed (P<0.05) in T-3 than that of the control. Significant increases (P<0.05) in contents of inosinic acid, total free amino acid (TFAA) and essential free amino acid (EFAA) were also found in T-3. Texture assays showed significant differences (P<0.05) in hardness, adhesiveness and springiness between group T-3 as compared with those of T-1 and control. It indicated that dietary supplementation of NaCl appeared to be a promising practice to improve meat quality of white shrimp reared in low-salinity waters.