不同生长时期红螯螯虾肌肉和肝胰腺内氨基酸和脂肪酸变化分析

为了研究不同生长时期红螯螯虾(Cherax quadricarinatus)肌肉和肝胰腺内脂肪酸和氨基酸的动态变化，选取90 d (第二性征未发育)、140 d (第二性征发育成熟)和180 d (性腺发育成熟)的红螯螯虾，分别测定其肌肉和肝胰腺内氨基酸和脂肪酸的含量。结果显示，90 d红螯螯虾肌肉中的必需氨基酸总量显著高于其他2个时期(P<0.05)；而红螯螯虾肝胰腺内必需氨基酸总量和非必需氨基酸总量均随着日龄增加而逐渐下降。比较不同生长时期肌肉中脂肪酸含量发现，随着日龄增长，饱和脂肪酸(SFA)含量呈下降趋势；而单不饱和脂肪酸(MUFA)含量呈先上升后下降的变化趋势，140 d含量最高(25.69±0.42)%]；多不饱和脂肪酸(PUFA)含量呈上升的变化趋势。肝胰腺中SFA含量在 3个生长时期内无显著性差异(P>0.05)，MUFA含量呈先上升后下降的变化趋势，140 d含量最高(37.44±0.59)%]，而PUFA含量变化与MUFA正好相反。营养价值评估结果显示，180 d (可上市销售)的红螯螯虾肌肉内必需氨基酸指数(49.96%)高于联合国粮农组织/世界卫生组织(FAO/WHO)评分模式(31.50%)和全鸡蛋蛋白质模式(43.10%)，是较为理想的优质食物蛋白源。由上可知，在不同生长时期，肌肉和肝胰腺中的氨基酸、脂肪酸的主要消耗不同，研究结果对了解不同生长时期红螯螯虾营养需求、开发红螯螯虾配合饲料提供了参考依据。

Amino acid and fatty acid analyses in muscles and hepatopancreas of red crayfish at different growth stages

This study investigated changes in fatty acid and amino acid contents in the muscle and hepatopancreas of red crayfish (Cherax quadricarinatus) at different growth stages, i.e., before the second sex development (90 days), at maturation of second sex (140 days), and at gonadal maturity (180 days). Sixteen types of amino acids in the muscle were found, and the content of essential amino acids (EAAs) at 90 days was significantly higher than the other two periods (P<0.05). However, the content of EAAs and non-essential amino acids in the hepatopancreas of crayfish decreased gradually. Among fatty acids, the saturated fatty acids (SFA) in the muscle showed a decreasing trend; the monounsaturated fatty acid (MUFA) content first increased and then decreased, reaching peak content of (25.69±0.42%)% at 140 days, whereas the polyunsaturated fatty acid (PUFA) content increased from 90 to 180 days. Furthermore, the SFA content in the hepatopancreas showed no significant difference among the three growth periods (P>0.05); the MUFA content first increased and then decreased, peaking (37.44±0.59)% at 140 days, while the PUFA content showed the opposite trend. Moreover, the evaluation of nutritional value revealed that the EAA index (49.96%) of the muscle of 180-day-old (marketable) red crayfish was higher than the FAO/WHO score model (31.50%) and the whole egg protein model (43.10%), which is considered an ideal source of high-quality protein. In conclusion, the consumption of amino acids and fatty acids in the muscle and hepatopancreas is different. These results provide a theoretical reference for understanding the nutritional requirements of red crawfish at different stages of growth and development.