生态浮床对养殖水产品中重金属含量和肌肉品质的影响

为比较铺设海马齿生态浮床的鱼、贝混养池塘(实验塘)和鱼、贝单一养殖池塘(对照塘)的养殖质量,实验采用电感耦合等离子体质谱法(ICP-MS)测定黄鳍鲷、尼罗罗非鱼、鲻3种鱼的鳃、内脏和肌肉及近江牡蛎、泥蚶两种贝类软体部分的Ni、Cu、Zn、Cd和Pb 5种重金属含量,并进行食用安全性评价;同时,测定了两种模式下养殖的黄鳍鲷与尼罗罗非鱼肌肉中氨基酸和脂肪酸组成及一般营养成分,以进行肌肉品质评价。结果显示,实验塘中各种水产品食用部分的重金属含量均未超过国家水产品相关限量标准;对照塘中近江牡蛎软体部分中Cu和Cd的含量分别为57.113 mg/kg wet wt.和1.163 mg/kg wet wt.,泥蚶软体部分中Cd含量达到1.231 mg/kg wet wt.,均超过了限量标准。黄鳍鲷、尼罗罗非鱼、鲻3种鱼类肌肉的安全性评价结果显示,两组鱼肉的摄入均不会对人体健康造成潜在威胁。实验塘黄鳍鲷肌肉中的鲜味氨基酸含量显著高于对照塘,而实验塘尼罗罗非鱼肌肉中氨基酸总量TAA、必需氨基酸总量EAA、鲜味氨基酸含量DAA均显著高于对照塘(P0.05);实验塘两种鱼肌肉中粗蛋白和多不饱和脂肪酸含量较高,饱和脂肪酸含量低(P0.05)。研究表明,实验塘鱼体肌肉的营养价值高于对照塘,且肉质更加鲜美。

Effects of ecological floating bed on content of heavy metals and nutritional quality in aquatic products

To study the effects of ecological floating beds on the quality of aquatic products, three species of fish (Sparu latus, Oreochromis niloticus and Mugil cephalus) and two species of mollusk (Crassostrea rivularis and Tegillarca granosa) were collected from the polyculture pond with floating bed and traditional monoculture ponds. Concentrations of heavy metals including Ni, Cu, Zn, Cd and Pb were measured in muscles, gills and viscera of fish and in the edible part of mollusk for health risk assessment. Nutritional quality of S. latus and O. niloticus was analyzed in terms of their muscle nutrition, amino acids and fatty acids composition. The results showed that the concentrations of five heavy metals of all products from the experimental pond conformed to the criteria values for aquatic food in China. However, the concentrations of Cu (57.113 mg/kg wet wt) and Cd (1.163 mg/kg wet wt) in C. rivularis and the concentration of Cd in T. granosa from the control ponds were all beyond the criteria values. According to the Hazard Quotient, there will be no potential risks resulting from ingestion of fish from two kinds of ponds. Content of umami amino acid of S. latus from the experimental pond was significantly higher than that of the control pond. O. niloticus from the experimental pond had notably higher contents of TAA, EAA and DAA than those from control pond. Contents of polyunsaturated fatty acids of S. latus and O. niloticus from the testing pond were all higher than those in the control ponds, while opposite results were observed for the contents of saturated fatty acids. Generally, polyculture mode with in-situ ecological floating beds system demonstrated superiorities to the traditional monoculture mode according to the health risk assessment and nutritional quality of aquatic products.