饲料中L-肉碱对斑节对虾肌肉中肌苷酸含量的影响

Effects of dietary L-carnitine on inosine monophosphate in the muscle of Penaeus monodon

选用平均体重为(8.25±1.18)g的池塘养殖斑节对虾,随机分为4组,每组3个重复,每个水泥池(100 cm×100 cm×100 cm)养虾60尾,分别投喂添加0、50、100和200 mg/kg L-肉碱的配合饲料4周。在实验的第0、1、2、3、4周分别从每个重复中随机取样,测定肌肉中的肌苷酸含量,研究L-肉碱对斑节对虾肌肉风味的影响。结果显示,1周后,实验组对虾肌肉肌苷酸含量均有所提高,其中50 mg/kg的实验组肌苷酸含量比对照组高27.39%(P<0.05);2周后50 mg/kg的实验组比对照组高15.85%(P<0.05),随着肉碱添加浓度升高对虾肌肉中肌苷酸含量呈下降趋势;3、4周后,实验组肌苷酸含量均比对照组低,呈现明显的负相关。与野生斑节对虾相比,池塘养殖对虾肌苷酸含量均比野生的低,但使用实验配制的饲料养殖4周后的对照组则与其有接近趋势。

Commom Penaeus monodon with body weight of （8.25 ± 1. 18） g, adopted in an intensive culture pond, were allotted to four groups and fed diets supplemented with L-carnitine at a rate of 0 （control） , 50, 100, 200 mg/kg for four weeks. Twelve shrimp were sampled from each replication every week for the effects of L-carnitine on inosine monophosphate （IMP） in the muscle of Penaeus monodon. The study showed that L- carnitine obviously improved the content IMP in prawn muscle at the end of week 1. In the groups fed 50 mg/ kg L-carnitine, the content of IMP in prawn muscle increased by 27.39% compared to the control group, and the difference was significant （P 〈 0.05 ）. At the end of week 2, the groups fed 50 mg/kg L-camitine improved by 15. 85% （P 〈 0. 05）. It showed that the content of IMP in muscle decreased while the supplement with L-carnitine increased. All the trial groups were lower than control groups at the end of week 3 and week 4, and the group with 50 mg/kg decreased the least among the trial groups. The content of IMP in cultured shrimp muscle was much lower than that in wild shrimp; however, at the end of week 4, there were only little difference after feeding good experimental diet. All these results demonstrated that diets supplemented with L-carnitine could enhance the content of IMP in shrimp muscle, and the supplementation of 50 mg/kg L-carnitine to the diet for less than two weeks for the rearing was the optimum combination. It is a more effective way of feeding good diet to improve the flavor of cultured shrimp.