周期性饥饿对鮸幼鱼肌肉中主要营养成分的影响

在水温为（22±2）℃条件下,研究了周期性饥饿对早繁鮸Miichthys miiuy幼鱼肌肉中主要营养成分的影响。试验分为6组：一直投喂（S0组）、隔日投喂（S1组）、饥饿3 d投喂3 d（S3组）、饥饿6 d投喂6 d（S6组）、饥饿9 d投喂9 d（S9组）和饥饿12 d投喂12 d（S12组）。结果表明：随着周期性饥饿时间的延长,鮸幼鱼肌肉水分的含量明显上升,各饥饿组鱼的水分与对照组相比差异显著（P〈0.05）;蛋白含量呈下降趋势,S1、S3组与S0组无显著性差异（P〉0.05）,S6、S9、S12组间有显著差异（P〈0.05）,且这3组与S0组之间蛋白含量均存在显著性差异（P〈0.05）;脂肪和糖类含量明显下降,除S1、S3、S6组外,其余各组间脂肪含量均具有显著性差异（P〈0.05）,而各组间糖类含量均有显著性差异（P〈0.05）。鮸幼鱼肌肉中天冬氨酸、谷氨酸、亮氨酸和赖氨酸的含量均较高。经过不同时间周期性饥饿后,各试验组鱼中各种氨基酸的含量和氨基酸总量与S0组均差异显著（P〈0.05）,必需氨基酸总量呈现先下降后上升的趋势。随着饥饿时间的延长,饱和脂肪酸（SFA）显著下降（P〈0.05）,按下降的百分比计,下降趋势为C21：0〉C17：0〉C18：0〉C15：0〉C14：0〉C22：0〉C24：0〉C16：0〉C23：0;单不饱和脂肪酸（MUFA）呈现先下降后上升的趋势;而多不饱和脂肪酸（PUFA）呈现先上升后下降的趋势,按上升的百分比计,上升趋势为C18：3n-3〉C20：4n-6〉C20：5n-3〉C18：3n-6〉C22：6n-3〉C18：2n-6。说明鮸幼鱼在周期性饥饿过程中,首先利用饱和脂肪酸,然后利用低不饱和脂肪酸,最后才动用高不饱和脂肪酸。双键位置不同的脂肪酸在饥饿过程中的损失速度也有差异,具体为∑n-9 PUFA〉∑n-6 PUFA〉∑n-3 PUFA。

The effects of periodic starvation on nutritional composition in muscles of juvenile Chinese drum Miichthys miiuy

The effects of periodic starvation on proximate muscle composition in Chinese drum Miichthys miiuy juveniles bred early were investigated at （22±2）℃. The juveniles weighing 5.8 - 7.1 g were randomly divided into six groups （SO,S1 ,S3 ,S6,S9 and S12）, starved for 0, 1,3, 6, 9, and 12 days and then fed for 0, 1,3, 6, 9, and 12 days. The results showed that the moisture in difference groups were significantly different compared with SO （P 〈0. 05）, and increased with increase in starvation period. But there were no significant differences between the groups of S1 and S3, S6 and S9, S9 and S12. The protein content was reduced with the increasing starvation period, without significant differences among SO, S1 and S3 （P 〉0. 05）. With the increase in starvation period, the lipid content was found to decrease from 1.65% （SO） to 0. 85% （S12）, without significant differences between S3 and S6, S6 and S9. The carbohydrate content was significantly reduced from 2.77% to 1.84% among the groups. There were high contents of aspartic acid, glutamic acid, leucine and lysine in the muscles. After several different periodic starvation, both the total amino acid and the 16 kinds of amino acid contents were reduced significantly （P 〈 0.05）. The total essential amino acid content was decreased from 6.004% （SO） to 5.119% （$9）, but the total essential amino acids content in S12 reached to 5. 443%. The saturated fatty acid （SFA） contents were found to reduce significantly with the increase in starvation period （ P 〈 0.05 ）, and ranked descendantly in percentage as： C21：0 〉 C17：0 〉 C18：0 〉 C15：0〉 C14：0 〉 C22：0 〉 C24：0 〉 C16：0〉 C23：0. The monounsaturated fatty acid （MUFA） content was reduced firstly and then increased, but the polyunsaturated fatty acid content （PUFA） was firstly increased and then reduced, and ranked descendantly in percentage as： C18：3n-3〉 C20：4n-6 〉 C20：5n-3 〉 C18：3n-6〉 C22：6n-3 〉 C18：2n-6, The resul