UVA补光时间对凡纳滨对虾肌肉主要营养成分影响研究

The Effect of UVA Supplementation Time on the Main Nutrients of the Muscle of Penaeus vannameiNutrients of the Muscle of Penaeus vannamei

关键词:  凡纳滨对虾  UVA补光时间  营养成分

Key words:  Penaeus vannamei  UVA supplementation time  Nutrient content

摘要:

紫外光A波段(Ultraviolet A, UVA)是自然光的重要组成部分，具有一定的生态功能。本研究选取450尾体重为(9.56±0.10) g的凡纳滨对虾(Penaeus vannamei)以光周期为12L︰12D的全光谱LED灯[光强(1.00±0.02) W/m2]作为背景光源，在不同UVA [光强(1.00±0.02) W/m2]补光时间(0 h, T0 h; 2 h, T2 h; 4 h, T4 h; 8 h, T8 h; 12 h, T12 h)下进行为期28 d的养殖实验。结果显示，在不同UVA补光时长下，对虾肌肉中水分和粗灰分含量无显著差异，T2 h和T4 h组的粗脂肪含量显著增加，T2 h组的粗蛋白显著高于T4 h组外的其他组(P<0.05)，T8 h和T12 h组的粗脂肪显著低于其他各组(P<0.05)，但两组间差异不显著；T2 h和T4 h组氨基酸总量、必需氨基酸含量和赖氨酸含量均显著高于其他组(P<0.05)；凡纳滨对虾饱和脂肪酸(SFA)含量为27.85%~40.70%，单不饱和脂肪酸(MUFA)含量为10.63%~16.31%，多不饱和脂肪酸(PUFA)含量为38.81%~49.61%，其在T2 h和T4 h组显著高于其他各组(P<0.05)，且在两组间无显著差异。综上所述，2~4 h的UVA补光时间能够改善凡纳滨对虾肌肉的营养成分。

Abstract:

UVA is an important component of natural light and has certain ecological functions. However, it remains unclear whether UVA affects the nutrient composition of Penaeus vannamei. We built a supplementary light culture system for P. vannamei and used classic nutrient composition analysis techniques to analyze the nutrient, fatty acid, and amino acid composition of the shrimp muscle tissue after different supplementary UVA light durations. Our results provide a theoretical reference for the technological improvement of P. vannamei culture. A total of 450 shrimps [weighing (9.56±0.10) g] were included in a 28-day culture experiment with background lighting of 12L:12D photoperiod with full spectrum LED light [light intensity (1.00±0.02) W/m2]. The experimental design randomly included different UVA [light intensity (1.00±0.02) W/m2] supplementation (0 h, T0 h; 2 h, T2 h; 4 h, T4 h; 8 h, T8 h; 12 h, T12 h). The results revealed no significant variation in the water and crude ash content of the shrimp muscles after different UVA light durations. The crude fat content increased significantly in the T2 h and T4h groups (P<0.05). The crude protein was significantly higher in the T2h group than that in the other groups (P<0.05), except the T4h group. The crude fat was significantly lower in the T8 h and T12 h groups than that in all other groups (P<0.05), but there was no significant difference between the T8 h and T12 h groups. Among saturated fatty acids (SFA) in the shrimp muscle, C16:0 was highest (with 17.19%–27.03%), followed by C18:0 (with 7.82%–10.99%), and both were significantly higher in the T2 h and T4h groups (P<0.05). The dominant monounsaturated fatty acids were C18:1n-9 (with 8.46%– 14.21%), and were significantly higher in the T2h and T4h groups (P<0.05). Linoleic acid and EPA were significantly higher in the T2 h and T4 h groups (P<0.05). The SFA content was 27.85%–40.70%, MUFA was 10.63%–16.31% and PUFA was 16.31%. The total content of n-3 and n-6 polyunsaturated fatty acids was significantly higher in the T2 h and T4 h groups than those in the other groups (P<0.05), and was significantly lower than those in the T12 h group, and significantly low than those in the T8 h group (P<0.05). However, the difference between the T12 h and T8 h groups was not significant (P>0.05). Seventeen common amino acids (excluding tryptophan, which was not detected) were detected in the muscle of P. vannamei. These included seven essential amino acids (EAA), two semi-essential amino acids (HEAA) and eight non-essential amino acids (NEAA). The results showed significant variation between the fraction of the 17 amino acids at different UVA light supplementation durations, with three essential amino acids (methionine, leucine, and lysine), one semi-essential amino acid (arginine), three non-essential amino acids (aspartic acid, glutamic acid, and glycine) and total, essential, semi-essential and non-essential amino acids in the T2 h and T4 h groups. The content of the three essential amino acids (threonine, isoleucine, and phenylalanine) did not differ significantly (P>0.05) with the different UVA light supplementation durations. The amino acid composition in the shrimp muscles showed that among the 17 amino acids at different UVA supplementation durations, the highest levels were glutamic acid with 2.02%, 2.72%, 2.71%, 1.95% and 1.93% in the T0 h, T2 h, T4 h, T8 h, and T12 h groups respectively, followed by glycine, aspartic acid, arginine, leucine, and lysine. The cystine content was the lowest, at 0.02%, 0.03%, 0.04%, 0.03% and 0.04% in the T0 h, T2 h, T4 h, T8 h, and T12 h groups, respectively. The EAA/TAA of shrimp muscle at different UVA supplementation durations ranged from 0.36 to 0.38 and EAA/NEAA from 0.68 to 0.73, with no components varying significantly between the treatments (P>0.05). The evaluation of the nutritional composition of the muscle of P. vannamei under different UVA light supplementation durations identified the muscle composition of shrimp in the T2 h and T4 h groups was high in protein and fat, while other nutritional components did not vary significantly from the other three groups. The EAA, HEAA, NEAA, and TAA contents, as well as the C16:0 and polyunsaturated fatty acids were higher in the T2 h and T4 h groups than those in the other groups. Therefore, shrimp in the T2 h and T4 h groups were more nutritious with a better nutritional status. In terms of the nutritional composition of the muscles of P. vannamei, 2–4 h of UVA supplementation can improve their nutritional quality and increase their nutritional value to a certain extent. In conclusion, the aquaculture light environment for P. vannamei requires further optimization.