盐度对哈氏仿对虾肌肉一般营养成分和氨基酸组成及含量的影响

通过调查不同盐度(12～36)环境下养殖的哈氏仿对虾(Parapenaeopsis hardwickii)肌肉一般营养成分和氨基酸组成及含量,研究了盐度对该虾肌肉营养品质的影响。结果显示,肌肉的水分随环境盐度升高出现显著的直线下降,而粗蛋白含量随环境盐度升高而直线升高;各盐度组的粗脂肪含量虽然没有明显差异,但其含量随盐度升高有一定的线性下降趋势;36盐度组的粗灰分含量比12、16、20和28盐度组的明显高,32盐度组的灰分含量比20和24盐度组的也明显高;所检测的肌肉干样16种氨基酸中,只有3种氨基酸的含量随盐度升高而升高,而其他13种氨基酸的含量随盐度升高明显降低,其中有10种氨基酸的含量在盐度12～24条件下的比盐度28～36条件下的明显高,而这些氨基酸含量在盐度12～24之间没有明显差异。各盐度组间氨基酸总量和鲜味氨基酸含量均没有明显差异;必需氨基酸和半必需氨基酸含量在盐度12～24条件下的均比盐度28～36条件下的明显高,而在12～24盐度组之间以及28～36盐度组之间均没有明显差异。必需氨基酸/氨基酸总量的比值和必需氨基酸/非必需氨基酸比值随盐度升高均明显线性降低;盐度12～24组的必需氨基酸指数(66.13～67.42)高于盐度28～36组的(62.56～64.46)。综上所述,盐度12～24环境下养殖的哈氏仿对虾肌肉营养价值相对较高,表现为低盐趋向,考虑到肌肉的水分含量和生长性能,哈氏仿对虾在养殖期间选择16～24盐度范围比较合适,同时也说明哈氏仿对虾适合大多数沿海地区环境的盐度条件。

Effects of Salinity on Nutrient Composition, Amino Acid Composition and Content in the Muscle of Parapenaeopsis hardwickii

The effect of salinity on muscle quality of the Sword Prawn (Parapenaeopsis hardwickii)was studied through testing the muscle nutrient composition, amino acid composition and content by culturing in different salinities. The results showed that the muscle moisture content significantly decreased, while the muscle protein content significantly increased with an increase in environment salinity from 12 to 36. No significant difference in muscle crude fat content was observed with salinity increase, although there was a slight decrease; The crude ash content at salinity 36 was significantly higher than that at salinity 12, 16, 20, 24 or 28. Among the 16 amino acids detected in the muscle, the content of 3 kinds significantly increased, while the content of other 13 kinds significantly decreased with an increase in salinity from 12 to 36; the content of 10 amino acids at salinity 12-24 was significantly higher than that at salinity 28-36, while no significant difference was detected from salinity 12 to24. No significant difference was found in total amino acid content or delicious amino acid content from salinity12 to 36. Both total essential amino acid content and total half-essential amino acid content at salinity 12-24 were significantly higher than those at salinity 28-36, while there was no significant difference from salinity 12 to 24 or from 28 to 36. Both the ratio of total essential amino acid to total amino acid and the ratio of total essential amino acid to total non-essential amino acid were significantly decreased with an increase in environment salinity from 12 to 36. The essential amino acid indexes (EAAI) at salinity 12-24(66.13-67.42)were higher than those at salinity 28-36(62.56-64.46). The results suggest that the optimal salinity range for muscle nutritive value is salinity 12-24, and that the Sword Prawn shows a low salinity trend. Considering the muscle moisture content and shrimp growth performance, the suitable salinity range for culture is salinity 16-24, and thus the Sword Prawn can potentially be cultured in the brackish water (16-24 salinity) existing in majority of the coastal areas.