养殖2龄赤点石斑鱼(Epinephelus akaara)的营养价值与畸形原因分析

Nutritional Values of 2-Year-Old Cultured Epinephelus akaara and Causes of Its Common Deformities

中文关键词: 赤点石斑鱼  畸形  肌肉营养成分  矿物质

英文关键词: Epinephelus akaara  Deformity  Muscle nutrient components  Mineral

中文摘要:

      分析了在工厂化条件下养殖的赤点石斑鱼(Epinephelus akaara)出现的畸形现象，发现其发育畸形特征可分为脊椎畸形和鳃颌畸形两大类。为了获得其营养学研究的基础资料，采用营养学方法测定和分析了正常、脊椎畸形、鳃颌畸形3种类型的鱼形体指标、肌肉成分及品质。结果显示，(1) 脊椎畸形与鳃颌畸形鱼的全长、肌肉率分别为(21.97±1.50) cm、(71.12±1.45) %和(22.43±0.12) cm、(71.28±0.39) %，都与正常鱼的指标值(25.70±0.75) cm、(78.58±0.20) %差异显著；(2) 3种类型鱼的肌肉中粗蛋白和粗灰分含量比较接近，差异不显著。脊椎畸形鱼的粗脂肪含量为(3.55±0.06) %，与正常鱼和鳃颌畸形鱼(2.71±0.07) %、(2.48±0.01) %差异显著；(3) 脊椎畸形鱼的氨基酸总量(TAA)和必需氨基酸指数(EAAI)分别为(17.55±0.65) %、83.04，鳃颌畸形鱼分别为(15.89±0.11) %、73.82，低于正常鱼的(19.86±0.52) %和89.25；(4) 从内聚性、弹性、胶粘性和咀嚼性4个方面对3种类型鱼的肌肉品质评价研究表明，上述4个指标值的大小(规律)为正常鱼＞脊椎畸性鱼＞鳃颌畸形鱼。两类畸形鱼的营养价值低于正常鱼，其中鳃颌畸形鱼的最低。实验还对3类鱼脊椎、鳃颌骨中的Cu、Zn、Fe、Mn、Ca、P等含量进行了测定，研究表明，脊椎中其他各元素间含量差异不显著，仅有Fe、Mn差异显著，说明Fe、Mn可能造成人工养殖的赤点石斑鱼脊椎畸形。

英文摘要:

      Common malformations were observed in artificially cultured Epinephelus akaara. The malformations could be divided into two categories: the spinal deformity and gill jaw deformity. To compare the nutritional values of the two types of deformed fish and normal ones, conventional nutrient determination methods were applied to analyze the body indices and muscle nutrient component and quality. The results were shown as follows:(1) The total length and muscle rate of spinal deformed fish were (21.97±1.50) cm and (71.12±1.45)% respectively. Those of gill and jaw deformed fish were (22.43±0.12) cm and (71.28±0.39)%. The values of both were significantly different from those of normal fish (25.70±0.75) cm and (78.58±0.20)%. (2) The difference in muscle crude protein and crude ash between the three types was small and insignificant, whereas the crude fat content of spinal deformed (3.55±0.06)%, there was a significant difference between the normal fish (2.71±0.07)% and gill jaw deformed (2.48±0.01)%. (3) The amino acid content and essential amino acid index of spinal deformed [(17.55±0.65%) and 83.04] and gill jaw deformed[ (15.89±0.11)% and 73.82] were lower than those of normal fish [(19.86±0.52)% and 89.25]. (4) In terms of meat quality, cohesion, elasticity, adhesiveness, and chewiness were compared between the three groups, and the order was normal fish > spinal deformed fish > fish gill and jaw deformed fish. Comprehensive analysis suggested that nutritional values of the two types of deformed fish were lower than that of normal fish, and it was the lowest in the gill and jaw deformed. In addition, we also tested the levels of elements such as Cu, Zn, Fe, Mn, Ca, and P in spines and gill and jaw bones of the three types of fish. We found that there was no significant difference in these elements in the spine, except for Fe and Mn. This indicated that the change in Fe and Mn content might be the cause of spinal deformity in cultured E. akaara.