浮筏养殖与底栖野生岩扇贝营养成分的分析与比较

为研究浮筏养殖与底栖野生两种生长环境对岩扇贝Crassadoma gigantea或贝营养成分的影响,采用常规营养成分分析方法,对在两种不同条件下生长的岩扇贝筏养(壳长为11.89 cm±0.50 cm)、野生岩扇贝(壳长为15.24 cm±1.36 cm)闭壳肌及非闭壳肌软体部的一般营养成分、脂肪酸、氨基酸和矿物元素含量进行了测定和比较。结果表明:筏养岩扇贝个体的软体部比例(26.07%)显著高于野生个体(17.69%)(P0.05),但两者闭壳肌比例差异不大;筏养岩扇贝个体的闭壳肌和非闭壳肌软体部的粗脂肪含量(0.37%、3.70%)显著高于野生个体(0.20%、3.51%)(P0.05),在两种生长条件下,岩扇贝的水分、灰分、粗蛋白质含量间均无显著性差异(P0.05);筏养岩扇贝个体闭壳肌和非闭壳肌软体部脂肪酸中的二十二碳六烯酸(DHA)含量(26.68%、17.01%)显著高于野生个体(18.09%、7.83%)(P0.05),而二十碳五烯酸(EPA)含量(18.52%、17.11%)显著低于野生个体(23.75%、23.93%)(P0.05),但筏养与野生岩扇贝的饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)、多不饱和脂肪酸(PUFA)、高度不饱和脂肪酸(HUFA)和EPA+DHA含量在相同组织间均无显著性差异(P0.05);野生岩扇贝的必需氨基酸指数(EAAI)平均值(80.13)明显高于筏养岩扇贝(63.70),且野生个体非闭壳肌软体部的氨基酸总量(TAA)、必需氨基酸含量(EAA)、呈味氨基酸含量(DAA)均高于筏养个体,但野生与筏养个体闭壳肌中的TAA、EAA、DAA含量相差不大,筏养与野生岩扇贝的呈味氨基酸占总氨基酸比例(DAA/TAA)、必需氨基酸占总氨基酸比例(EAA/TAA)也非常接近;筏养个体闭壳肌中Se和K的含量分别为野生个体的3倍和2倍,而Fe含量仅为野生个体的三分之一。研究表明,浮筏养殖与底栖野生岩扇贝除了少量指标外,营养成分基本一致。

Comparison of nutritive composition between raft cultured and benthic wild rock scallop Crassadoma gigantea

Approximate composition,fatty acids, amino acid and mineral element were comparatively analyzed in adductor and non-adductor soft part between raft cultured (shell length of 11.89 cm ± 0.50 cm)and benthic wild (shell length of 15.24 cm ± 1.36 cm) rock scallop Crassadoma gigantea by means of ordinary nutritive analytical method. The results showed that there was significantly higher soft part proportion (26.07%) in raft cultured rock scallop than that in wild ones (17.69%) (P<0.05), without significant difference in adductor proportion (P>0.05). There were significantly higher crude fat in adductor(0.37%) and non-adductor soft part(3.70%) in raft cultured rock scallop than those (0.20% and 3.51%) in wild ones(P<0.05), without significant differences in moisture and contents of crude protein and total ash between raft cultured and wild samples (P>0.05). The rock scallop cultured in rafts had docosahexenoic acid (DHA) content of 26.68% in adductor and 17.01% in non-ad-ductor soft part,higher than the wild rock scallop(18.09%,7.83%)did. The rock scallop cultured in rafts had low-er eicosapentaenoic acid(EPA) content of 18.52% in adductor and 17.11% in non-adductor soft part than the wild rock scallop(23.75%and 23.93%)did,without significant difference in the content of saturated fatty acid(SFA), mono-unsaturated fatty acid(MUFA), poly-unsaturated fatty acid (PUFA) and highly unsaturated fatty acid (HUFA) including total EPA and DHA contents within the same tissue in the two kinds of rock scallop. The aver-age essential amino acid index (EAAI) was higher in wild individuals (80.13) than that in cultured individuals (63.70). In non-adductor soft part,the contents of total amino acid(TAA),essential amino acid(EAA),and de-licious amino acid(DAA)were higher in wild rock scallop than those in the raft cultured ones,with the nearly same indices in adductor. The similar EAA/TAA ratio and DAA/TAA ratio were observed in the two growth mode rock scallops. The raft cultured rock scallop had high level mineral elements,especially three times and two times higher Se and K contents than the wild rock scallop did,respectively,and 1/3 times Fe in the wild rock scallop.The find-ings indicated that the nutritive composition of raft cultured rock scallop were similar to those in benthic wild rock scallop except a few nutritive composition.