野生和养殖梭鲈肌肉营养组成分析与评价

Analysis and Evaluation of Nutritional Composition in Muscle of Wild and Farmed Pike-perch Sander lucioperca

采用常规方法测定了2018年4—7月在乌苏里江抚远江段用挂网捕获的体长43.5~50.9cm、体质量1.6~2.5kg的野生和体长38.5~40.0 cm、体质量0.8~1.0kg的养殖梭鲈Sander lucioperca肌肉的营养成分,并用标准方法评价了梭鲈的营养品质。结果显示:梭鲈肌肉(鲜重)中蛋白质含量为20.23%~21.03%,必需氨基酸和鲜味氨基酸含量占总氨基酸含量的39.73%~40.74%和38.93%~40.10%。野生梭鲈(20.23%)肌肉蛋白含量显著低于养殖梭鲈(21.03%)(P<0.05);必需氨基酸与非必需氨基酸比值高达77.03%~81.10%,符合FAO/WHO推荐的理想蛋白质标准。根据氨基酸评分(AAS),梭鲈肌肉的第一限制氨基酸为缬氨酸,第二限制氨基酸为蛋氨酸。梭鲈肌肉中不饱和脂肪酸含量极为丰富,其中多不饱和脂肪酸(PUFA)含量占总脂肪酸的45.67%~45.85%,特别是二十碳五烯酸(EPA)+二十二碳六烯酸(DHA)的含量高达30.66%~30.96%。野生和养殖梭鲈肌肉中脂肪含量分别为0.75%和0.70%,差异不显著(P>0.05);水分和灰分含量也无显著差异。养殖梭鲈肌肉中饱和脂肪酸(SFA)和单不饱和脂肪酸(MUFA)含量均高于野生梭鲈,其中MUFA含量差异极显著(P<0.01),但两者PUFA含量相似(45.85%和45.67%)。野生梭鲈肌肉中EPA含量(10.31%)高于养殖梭鲈(6.43%),而DHA含量(20.65%)则显著低于养殖梭鲈(24.23%)(P<0.05),二者EPA和DHA总含量接近,分别为30.96%和30.66%。综上所述,梭鲈肌肉是一种高蛋白、低脂肪、富含优质脂肪酸的健康食品。

The nutrient contents were determined in muscles of wild pike-perch Sander lucioperca with body length of 43.5 ~ 50.9 cm,and body weight of 1.6 ~ 2.5 kg captured by gillnets in Fuyuan section of Wusuli River from April to July by routine method and cultured pike-perch with body length of 38.5 ~ 40.0 cm, and body weight of 0.8 ~ 1.0 kg, and nutritional value and edibleness were evaluated to better understanding of the nutritional composition of the muscles of wild and farmed pike-perch using national standard methods. The results showed that the protein content in muscle(fresh weight)was varied from 20.23% to 21.03%, essential amino acids accounting for 39.73% ~ 40.74% and delicious amino acids accounting for 38.93% ~ 40.10% of the total amino acids. There was significantly lower muscular protein content in wild pike-perch(20.23%)than that in cultured pike-perch(21.03%)(P < 0.05), with the ratio of essential amino acid(EAA)to non-essential amino acids(NEAA)of as high as 77.03%~81.10%, which is fully in line with the ideal protein standard recommended by FAO/WHO. The amino acid score(AAS)value indicated that the first limiting amino acid of the muscle was valine and the second one was methionine. Pike-perch had rich in content of unsaturated fatty acids in muscle, among which polyunsaturated fatty acids(PUFA)accounted for 45.67% ~ 45.85% of the total fatty acids, especially eicosapentaenoic acid(EPA)+ docosahexaenoic acid(DHA)as high as 30.66% ~ 30.96%, without significant difference in fat content and in moisture and ash content between wild(0.75% of fat)and cultured(0.70% of fat)pike-perch(P > 0.05). The contents of saturated fatty acid(SFA)and monounsaturated fatty acid(MUFA)in muscle were shown to be higher in cultured pike-perch than those in wild pike-perch, with vary significant difference in the contents of MUFA(P < 0.01), and without significant difference in the PUFA contents between cultured(45.85%)and wild(45.67%). There was higher muscular EPA content(10.31%)in wild pike-perch than that in cultured one(6.43%), while significantly lower DHA content of(20.65%)in wild pike-perch than that in cultured one(24.23%)(P < 0.05). The total content of EPA and DHA in wild pike-perch(30.96%)was close to that in the cultured pike-perch(30.66%). In conclusion, pike-perch is a kind of healthy food with high protein, low fat and high quality fatty acid contents.