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1.
Cells from a relatively stenohaline marine species, turbot (Scophthalmus maximus) (TF) and an anadromous species, Atlantic salmon (AS) were cultured in media supplemented with NaCl to produce OPs varying from 300 to 500 mOsm kg–1 and the direct effects of OP (salinity) on the fatty acid compositions of the main glycerophospholipid classes were determined. The most dramatic effects of salinity on total lipid fatty acids were observed in polyunsaturated fatty acids (PUFA) in TF cells. There was a graded decrease in the percentage of 18:2n-9, and consequently total n-9 PUFA, and concomitantly increased percentages of both total n-3 and n-6 PUFA with increasing salinity. The increased n-3 and n-6 PUFA was due to significantly increased percentages of the major fatty acids in each of these groups, namely 22:6n-3 and 20:4n-6, respectively. The reciprocal changes in n-9 PUFA and n-3/n-6 PUFA in TF cell total lipid resulted in the percentage of total PUFA not being significantly affected by changes in salinity. The graded decrease in 18:2n-9 with increasing salinity in TF cells was observed in all the major glycerophospholipids but especially PE, PI and PS. Increasing salinity resulted in graded increases in the percentages of 22:6n-3 in PE and PS in TF cells. The quantitatively greatest increase in the percentage of n-6 PUFA in TF cells occurred with 20:4n-6 in PC, PE and PL. There were less significant changes in the fatty acid compositions of glycerophospholipids in AS cells. However, the proportion of total n-3 + n-6 PUFA in PE varied reciprocally with the proportion of dimethylacetals in response to salinity. Similar reciprocal changes between fatty acids in response to salinity were also evident in the quantitatively more minor glycerophospholipids PS and Pl. In PS, the percentage of 22:6n-3 was significantly lower at 400 mOsm kg–1 whereas the proportion of total monoenes was significantly higher at that salinity. A similar inverse relationship between total monoenes and 20:4n-6 (and, to a lesser extent total saturates) in response to salinity was noted in PI. The results show that environmental salinity, without whole-body physiological stimuli, has direct effects on the fatty acid composition of major glycerophospholipid classes in fish cells and that these effects differ in cells from different fish speciesAbbreviations ANOVA analysis of variance - BHT butylated hydroxytoluene - BSA bovine serum albumin - DMA dimethylacetals - EMEM Eagle's minimal essential medium - FCS fetal calf serum - GC gas chromatography - HBSS Hank's balanced salt solution (without Ca2+ and Mg2+) - OP osmotic pressure - PC phosphatidylcholine - PE phosphatidylethanolamine - PI phosphatidylinositol - PS phosphatidylserine - PUFA polyunsaturated fatty acid - TLC thin-layer chromatography  相似文献   

2.
Three diets in which the lipid component was supplied either as fish oil (FO), linseed oil (LO) or olive oil (OO) were fed to duplicate groups of juvenile turbot (Scophthalmus maximus) of initial weight 1.2 g for a period of up to 12 weeks. The latter two diets resulted in a significant reduction in specific growth rate and an increased mortality compared to the FO (control) fed fish. A liver histopathology was evident in around half of the fish fed the LO and OO diets but was absent in fish fed FO. The lesion showed indications of cellular alterations consisting of foci of densely basophilic cells but without evidence of inflammatory activity. The total lipid fatty acid composition of the carcass from fish fed LO had increased percentages of 18:2n-6 and 18:3n-3, but decreased percentages of all other polyunsaturated fatty acids (PUFA) including the physiologically important 20:4n-6, 20:5n-3 and 22:6n-3, compared to fish fed FO. Almost 2/3 of the total fatty acids in the carcass of OO-fed fish were monounsaturated while the percentages of total saturated fatty acids and all other PUFA, except 18:2n-6, were significantly reduced compared to fish fed FO. Broadly similar effects on total lipid fatty acid composition were observed in liver. In the liver glycerophospholipid classes of fish fed LO, percentages of 18:2n-6, 18:3n-3 and 20:3n-3 were significantly increased whereas all C20 and C22 PUFA, with the exception of 20:5n-3 in PI, were significantly reduced compared to fish fed FO. The liver glycerophospholipids of fish fed OO all showed significantly increased total monounsaturates, 18:2n-6, 20:2n-6, 18:2n-9 and 20:2n-9 as well as reduced percentages of 20:4n-6 and 22:6n-3, compared to fish fed FO. The brain glycerophospholipids showed broadly similar changes in response to dietary treatment although the magnitude of fatty acid alterations was less than those observed in liver. The greater mortalities in the OO-fed fish compared to the LO-fed fish suggests that incorporation of 18:3n-3 into tissue phospholipids can offset losses of long-chain PUFA more effectively than incorporation of 18:1n-9. However, levels of dietary long-chain PUFA must be optimised to allow normal growth and development. We conclude that the very low flux through the fatty acid desaturase/elongase pathways in turbot is not up-regulated by diets deficient in 20:5n-3 and 22:6n-3.  相似文献   

3.
Arctic charr (Salvelinus alpinus L.) were fed either a commercial diet or six experimental test diets containing coconut oil and different polyunsaturated fatty acids (PUFA) at a level of 1% by dry weight. Best growth rates were observed with the commercial diet, worst with diet containing coconut oil with no PUFA. An increase in hepatic lipid, hepatic sterol esters and muscular moisture content, and a decrease in muscular lipid was generally found in fish fed the test diets compared to those maintained on the commercial diet.Phosphatidylcholine was the dominant polar lipid (PL) class in all tissues examined. Extensive modification of dietary saturated fatty acids into 18:1 (n-9) was observed in tissue triacylglycerols (TAG) of fish fed test diets. No changes occurred with the commercial diet.Dietary PUFA were essentially incorporated unchanged into tissue TAG of all fish in the present study. PUFA composition of hepatic phospholipids was significantly influenced by that contained in the diets. However both 18:2 (n-6) and 18:3 (n-3) in the test diets were extensively elongated and desaturated prior to incorporation into PL. The (n-9) PUFA content was always higher in liver of fish fed the test diets. When 18:2 (n-6) and 18:3 (n-3) were supplied together, the level of (n-3) PUFA exceeded those of (n-6) PUFA. Muscle PL were less influenced by diet than liver. In muscle (n-3) PUFA were always the predominant PUFA irrespective of diet. Only low amounts of (n-9) PUFA were found. It is suggested that (n-3) PUFA are the prime essential fatty acids for Arctic charr, and that they are used in preference to (n-6) PUFA for elongation, desaturation and incorporation into PL. The results suggest that the quantitative requirement of Arctic charr for EFA is may be higher than that of other salmonids.  相似文献   

4.
本研究比较和分析网箱与微流水两种养殖模式下体质量(76.5±17.8)g和(67.2±8.1)g的齐口裂腹鱼Schizothorax prenanti肌肉常规营养成分。结果显示:两组齐口裂腹鱼肌肉中一般营养成分含量不存在显著性差异,均含有18种氨基酸;除色氨酸(Trp)和组氨酸(His)外,网箱组齐口裂腹鱼肌肉中其余氨基酸、氨基酸总量、必需氨基酸总量和鲜味氨基酸总量均显著低于微流水组。氨基酸评分(AAS)和化学评分(CS)结果显示:两组齐口裂腹鱼肌肉中必需氨基酸构成合理,色氨酸均为第一限制性氨基酸,赖氨酸在必需氨基酸中评分最高。两组齐口裂腹鱼肌肉中均含有21种脂肪酸,网箱组饱和脂肪酸(SFA)总量和单不饱和脂肪酸(MUFA)含量显著低于微流水组,而多不饱和脂肪酸(PUFA)含量显著高于微流水组,且n-3/n-6比值要高于网箱组。综上所述,微流水养殖的齐口裂腹鱼营养价值更高。  相似文献   

5.
亚东鲑(Salmo trutta fario)是鲑属鱼类在青藏高原仅有的鱼类种群,是亚东地区全国农产品地理标志产品。本研究对西藏亚东地区野生和养殖亚东鲑的常规营养成分及各组织氨基酸和脂肪酸组成进行分析,旨在比较野生和养殖亚东鲑营养成分的异同,为养殖亚东鲑的品质评价和饲料配方的完善提供参考信息。实验采集亚东河中野生亚东鲑和亚东渔业产业园中使用配合饲料养殖的亚东鲑各10尾用于相关成分分析,每尾为一个独立样本。结果显示,野生组肥满度显著低于养殖组,而全鱼水分和灰分显著高于养殖组。全鱼粗蛋白、粗脂肪以及肝脏常规成分在野生组和养殖组间无显著差异。野生组肌肉粗脂肪显著低于养殖组,而水分含量显著高于养殖组。野生组全鱼必需氨基酸总量显著高于养殖组,且野生组肌肉中苏氨酸、缬氨酸、苯丙氨酸、赖氨酸和甘氨酸含量显著高于养殖组。野生组全鱼、肌肉和肝脏中饱和脂肪酸、n-3多不饱和脂肪酸(n-3 PUFA)总量、EPA、C20:4n-6以及肌肉中DHA含量高于养殖组,而全鱼和组织中单不饱和脂肪酸和n-6 PUFA总量低于养殖组。综上所述,目前养殖亚东鲑和野生亚东鲑在机体成分上存在较大差异。由于养殖鱼类体成分很大程度上反映了饲料组成,因此,亚东鲑养殖中饲料营养组成可能有待进一步优化。  相似文献   

6.
不同脂肪源对真鲷幼鱼生长、存活及体内脂肪酸组成的影响   总被引：16，自引：2，他引：14  
真鲷幼鱼摄食缺乏多不饱和脂肪酸(PUFA)饵料时,其生长增重率和存活率比摄食富含PUFA配合饵料或玉筋鱼鱼糜的明显下降。幼鱼摄食含有不同脂肪酸饵料时,其肌肉和肝脏组极性或非极性脂中脂肪酸组成都有变化。肌肉和肝脏极性脂中的PUFA比非极性脂中PUFA含量高,并且当饵料中不能提供足够的PUFA时,非极性脂中的PUFA下降明显,而极性脂中的PUFA变化较小,被优先贮存。真鲷幼鱼肌肉和肝脏组织缺乏n-9、n-6和n-3相互转化的能力。因此,为提高幼鱼的生长增重率和存活率,必须保证饵料中含有足够的PUFA。  相似文献   

7.
Fatty acid profiles of the total lipids and the phospholipid classes of farm-raised channel catfish (Ictalurus punctatus) fillets were analyzed. Monoenes represented 49.22 mol% of the total lipid fatty acids while polyunstaturated fatty acids (PUFA) accounted for 19.37 mol%. The total n-3 PUFA content was low (4.22 mol%). The total saturated fatty acids as 31.44 mol %. Catfish contained phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylserine (PS), lysophosphatidylcholine (LPC), and sphingomyelin (SPH). Analysis for the individual phospholipid class fatty acid profiles indicated that PI had a high concentration of 18:0 (33.20 mol%) and 20:4 n-6 (13.08 mol%). Phosphatidylethanolamine had the highest concentrations of combined eicosapentaenoic acid, and docoshahexaenoic acid, of 17.37 mol%. Higher ratios of n-3/n-6 PUFA were found in the phospholipid classes than the total lipids. LPC and SPH did not contain measurable PUFA of the n-3 series. The level of 18:1 n-9 in PC, PE, and LPC was approximately 31 mol% whereas in PI, PS, and SPH, the level was approximately 16 mol%. The understanding of the basic distribution of fatty acids in the individual phospholipid classes of channel catfish may be an essential first step in explaining the protective role of 18:1 n-9 and n-3 PUFA against thrombotic and cardiovascular disorder in humans.  相似文献   

8.
The effect of long-term culture of fish cells in mammalian serum on the phospholipid fatty acid composition was investigated. All the cell lines studied had much lower levels of polyunsaturated fatty acids (PUFA) than those found in intact fish tissues. In particular (n-3) PUFA were considerably depleted in the cultured cell lines, leading to very low (n-3)/(n-6) ratios in all the phospholipid classes. In general the cells were rich in 18:1, 16:0, 18:0 and 16:1 with 20:4(n-6) and 22:6(n-3) as the major PUFA. The fatty acid composition reflected the composition of the fetal calf serum added to the media rather than their fish tissue origins. The results were discussed in relation to the roles of PUFA in general cell metabolism and more specifically the role of (n-3) PUFA in fish cells.  相似文献   

9.
Atlantic salmon fry (4 g) were fed a semi-synthetic diet devoid of n-3 and n-6 polyunsaturated fatty acids (PUFA) for 4 months. External signs of nutritional imbalance during the period were slow growth rate and increased mortality. Some symptoms of essential fatty acid deficiency appeared in the fatty acid composition of the blood and liver during the fourth month. At that time, the percentages of n-3 and n-6 PUFA of triacylglycerols (TAG) were nearly exhausted, and the percentages of 22:6 n-3 and of 20:5 n-3 in phospholipids (PL) showed a marked decrease. This decrease in the PUFA level of the PL was paralleled by the appearance of 20:3 n-9, whereas in the TAG an increase in the percentage of 18:1 n-9 was observed. After 4 months the monounsaturated fatty acid 18:1 n-9 constituted nearly 50% of the fatty acids in the TAG fraction of the liver. The time course of the changes in fatty acid composition of liver and blood lipids was quite similar, whereas the carcass lipid composition appeared to respond slowly to a diet devoid of essential fatty acids.  相似文献   

10.
不同饵料饲养的褐牙鲆肌肉营养成分的比较   总被引：9，自引：1，他引：9  
比较分析了分别投喂小杂鱼和人工饲料的两组褐牙鲆肌肉营养成分,旨在为褐牙鲆的营养需求研究及其饲料研制提供参考。结果显示:摄食小杂鱼组的水分含量显著低于摄食人工饲料组(P<0.05),而粗蛋白和粗脂肪含量显著高于摄食人工饲料组(P<0.05),粗灰分含量在两组间差异不显著(P>0.05);两组褐牙鲆的氨基酸组成基本一致,均含有18种氨基酸,必需氨基酸指数(EAAI)分别为71.15和70.47,其构成比例符合FAO/WHO的标准。摄食小杂鱼组褐牙鲆中检测到11种饱和脂肪酸(SFA)、6种单不饱和脂肪酸(MUFA)和9种多不饱和脂肪酸(PUFA);摄食人工饲料组中检测到11种SFA、7种MUFA和9种PUFA。摄食小杂鱼组的∑ω3PUFA[(30.39±2.29)%]显著低于摄食人工饲料组[(34.40±3.32)%](P<0.05),其中小杂鱼组的EPA+DHA的总量为(29.27±2.33)%,显著低于摄食人工饲料组的(33.47±3.36)%(P<0.05);摄食小杂鱼组的∑ω6PUFA为(6.01±0.31)%,显著高于摄食人工饲料组的(5.06±0.37)%(P<0.05)。综合来看,两组褐牙鲆均含有丰富的各种营养成分,摄食小杂鱼组的粗蛋白、粗脂肪和氨基酸营养较好,而摄食人工饲料组的多不饱和脂肪酸营养较好,两者各有优势。  相似文献   

11.
为评估不同养殖环境对禾花鲤(Cyprinus carpio)肌肉营养与品质的影响,采用国标法检测稻田和池塘2种养殖环境下禾花鲤肌肉常规营养成分、质构特性、氨基酸和脂肪酸组成。结果显示,池塘组禾花鲤肌肉粗蛋白和粗脂肪含量显著高于稻田组(P<0.05),水分含量显著低于稻田组(P<0.05),灰分含量2组差异不显著(P>0.05);池塘组肌肉粘性显著高于稻田组(P<0.05),内聚性和剪切力显著低于稻田组(P<0.05),其他质构指标2组间差异不显著(P>0.05);肌肉氨基酸测定结果显示,池塘组氨基酸总量(?TAA)、鲜味氨基酸(DAA)、必需氨基酸(EAA)、非必需氨基酸(NEAA)显著高于稻田组(P<0.05),?EAA/TAA和?EAA/NEAA显著低于稻田组(P<0.05),2组禾花鲤必需氨基酸构成比例均符合FAO/WHO标准;在鲜味氨基酸含量方面,池塘组主要的4种呈味氨基酸含量均显著高于稻田组(P<0.05)。根据氨基酸评分(AAS)和化学评分(CS)标准,2组禾花鲤肌肉第一、二限制性氨基酸均分别为色氨酸(Trp)和缬氨酸(Val);在脂肪酸测定结果中显示,池塘组单不饱和脂肪酸(∑MUFA)含量显著高于稻田组(P<0.05),但多不饱和脂肪酸(∑PUFA)、EPA+DHA和∑n-3PUFA/ ∑n-6PUFA显著低于稻田组(P<0.05)。综上所述,池塘和稻田养殖条件下,禾花鲤均为优质的蛋白质来源,但不同养殖环境对禾花鲤肌肉营养与品质有显著影响。从常规营养成分、氨基酸评分方面看,池塘养殖条件下禾花鲤肌肉营养价值更高;从脂肪酸角度来看,稻田养殖禾花鲤肌肉具有较高的EPA+DHA含量以及n-3/n-6多不饱和脂肪酸比例,更适合高血脂和心血管疾病等患者食用,从质构性来看,稻田养殖环境下禾花鲤肌肉更具嚼劲。  相似文献   

12.
A marine fish oil, Marinol K (MO) and borage oil (BO) were used to formulate diets relatively rich in eicosapentaenoic acid [EPA; 20:5(n-3)] and -linolenic acid [GLA; 18:3(n-6)], respectively. The diets were fed to duplicate groups of juvenile turbot (Scophthalmus maximus) of initial weight 1.4 g for a period of 12 weeks. No differences were observed in final weights either between duplicate tanks or between dietary treatments. Mortalities in the MO-fed group were significantly greater than in the BO-fed group. In the MO-fed group, 7 out of 12 fish sampled for histological analysis showed a pronounced liver histopathology whereas only 1 of 12 fish sampled in the BO-fed group showed slight pathology. EPA levels were increased 2.2-fold and its elongation product, 22:5(n-3), was increased 1.8-fold while arachidonic acid [AA; 20:4(n-6)] was decreased by 30% in MO-fed fish compared to the initial carcass composition. GLA was increased 53-fold and its elongation product dihomo--linolenic acid [DHGLA; 20:3(n-6)] was increased 16-fold while AA was reduced by 90% in BO-fed fish compared to the initial carcass composition. The amount of triacylglycerol in liver of BO-fed fish was significantly greater than levels in MO-fed fish. The fatty acid compositions of individual phospholipids from liver showed marked differences between dietary treatments. Fish fed MO had significantly higher levels of the (n-3) polyunsaturated fatty acids (PUFA), 20:5(n-3), 22:5(n-3) and 22:6(n-3), and also significantly more 20:4(n-6) compared to BO-fed fish which had significantly higher 18:2(n-6), 18:3(n-6), 20:2(n-6) and 20:3(n-6). The composition of liver phosphatidylinositol was particularly unusual in BO-fed fish having DHGLA as the major C20 PUFA which was 2.2-fold greater than AA and 3.9-fold greater than EPA. This study demonstrates that the carcass composition of turbot can be altered, by means of dietary lipids, to contain increased levels of EPA and DHGLA which would be of potential benefit in human as well as in fish nutrition. However, caution should be exercised when using very highly unsaturated oils relatively rich in EPA which may generate histopathological lesions in the fish.Abbreviations AA arachidonic acid - ANOVA analysis of variance - BHT butylated hydroxytoluene - BO borage oil - DHA docosahexaenoic acid - DHGLA dihomo--linolenic acid - EPA eicosapentaenoic acid - GLA -linolenic acid - HPTLC high performance thin-layer chromatography - MO Marinol K - PC phosphatidylcholine - PE phosphatidylethanolamine - PI phosphatidylinositol - PS phosphatidylserine - PUFA polyunsaturated fatty acid - TLC thin-layer chromatography  相似文献   

13.
The influence of feeding high levels of polyunsaturated fatty acids (PUFA) on muscle fatty acid composition and indices of oxidative damage was examined in Arctic charr, Salvelinus alpinus (L.). All diets contained 100 g kg?1 lipid of dry weight. Two diets contained marine fish oils giving a PUFA level of 250 g kg?1 and 500 g kg?1 of lipid. The remaining two diets contained vegetable oils high in either 18:2n-6 or 18:3n-3, giving a PUFA level of more than 500 g kg?1 of dietary lipid. The charr were maintained at 8°C until their weight doubled, and were then transferred to 0.8°C for 30 days. Growth was similar in all groups. The fatty acid compositions of muscle were influenced by dietary PUFA but were less diverse than those of the diets. The overall pattern of fatty acid compositions indicated preferential desaturation and elongation of n-3 PUFA coupled with selective oxidation of 18:2n-6. Total n-3 PUFA content in TAG was always lowered compared with the diet, suggesting a specific mechanism for the removal of these fatty acids. Subjecting the fish to low temperature increased PUFA content in muscle of charr fed the 250 g kg?1 marine n-3 PUFA diet, but had no effect on the other treatments. For fish at 8°C, no significant differences were found between groups in terms of haematocrit, plasma alanine aminotransferase (ALAT), and plasma and muscle thiobarbituric acid reactive substances (TBARS), although there was a tendency towards increased levels of TBARS in the group receiving 500 g kg?1 marine n-3 PUFA of lipid. Subjecting the muscle to forced oxidative conditions resulted in increases in TBARS in all groups, particularly those fed 500 g kg?1 marine n-3 PUFA. Lowering the environmental temperature corresponded with a further increase in the plasma ALAT and muscle TBARS in this group. It is concluded that feeding diets containing high levels of long-chain n-3 PUFA may be detrimental to the fish's health and flesh quality, particularly at low environmental temperatures.  相似文献   

14.
Proximate composition, amino acid, fatty acid composition, and contaminants (As, Cd, Hg, and Pb) of the kisslip cuttlefish Sepia lycidas were determined and compared with the recommendations and maximum allowed levels. The ratio of essential amino acids (EAA) to nonessential amino acids (NEAA) was 0.82. All of the amino acid scores were > 100, except for valine (93), and the highest essential amino acid score was obtained for tryptophan (327). The fatty acids profile was dominated by polyunsaturated fatty acids (PUFA; 45.01% of total fatty acids), and docosahexaenoic acid (DHA; 24.54% of total fatty acids) was the dominant fatty acid. S. lycidas was rich in n-3 PUFA, and the ratio of n-3/n-6 PUFA was 2.48. Regarding contaminants, As, Cd, and Pb concentrations in S. lycidas were 2.2, 0.28, and 0.02 mg kg?1, respectively. Moreover, Hg values were below the detection limit (0.01 mg kg?1).  相似文献   

15.
分别取中华绒螯蟹(Eriocheir sinensis)池塘套养和温室养殖中华鳖(Trionyx sinensis)雄体(分别简称为"套养鳖"和"温室鳖")各5只,解剖取四肢肌肉、裙边和肝脏,分析和比较两种鳖的生物学指数,可食组织常规营养成分、氨基酸含量和脂肪酸组成的差异。结果显示:(1)温室鳖裙边指数(SI)和肝体比(HSI)均显著高于套养鳖(P0.05)。(2)套养鳖肌肉灰分和裙边水分含量均显著高于温室鳖,而裙边蛋白含量则以温室鳖较高(P0.01),套养鳖和温室鳖其余常规营养成分均无显著差异(P0.05)。(3)温室鳖肌肉和裙边中的大部分氨基酸、总必需氨基酸(∑EAA)和总氨基酸(TAA)含量显著高于套养鳖,半胱氨酸含量及EAA/TAA以套养鳖较高(P0.05);套养鳖和温室鳖肌肉和裙边中的必需氨基酸评分(EAAS)较为接近,而EAAS平均值以套养鳖较高。(4)温室鳖肌肉C18:1n9、C18:1n7及单不饱和脂肪酸(∑MUFA)总量显著高于套养鳖,而C22:6n3、总多不饱和脂肪酸(∑PUFA)、∑n-3PUFA、总高度不饱和脂肪酸(∑HUFA)含量及n-3/n-6以套养鳖较高(P0.05);就裙边而言,除温室鳖C17:0和C20:2n6含量显著高于套养鳖外(P0.05),其余脂肪酸含量均无显著差异(P0.05)。综上可见,中华鳖在两种养殖模式下均具有较高的营养价值。  相似文献   

16.
《水生生物资源》1998,11(6):379-385
The fatty acid profile of the galaxiid fish Galaxias maculatus (Salmoniformes) collected from an estuarine habitat (a river mouth), a freshwater creek and two land-locked freshwater lakes in Victoria, Australia, were investigated with a view to evaluating habitat influences on the fatty acid profile. Fish from the freshwater creek were unpigmented, fresh-run juveniles (referred to as whitebait), the others adult fish. The fatty acids that predominated in adult G. maculatus muscle were 16:0 and 22:6(n-3), and 16:0 and 18:1(n-9), respectively. In whitebait 22:6(n-3), 20:5(n-3) and 16:0 were predominant. Hopkins estuary fish had the highest amount of 18:2(n-6) but the lowest 18:3(n-3). In all galaxiid populations, polyunsaturated fatty acids (PUFA) were the main group of fatty acids in total lipid in muscle, and accounted for more than 40 %, followed by saturates and monoenes. In landlocked populations, the amount of monoenes was lower than in other galaxiid populations. G. maculatus whitebait had significantly lower amount of saturates and the highest amount of n-3 fatty acids. The ratio of n-3 to n-6 PUFA ranged from 4.6 (Hopkins estuary) to 7.6 (whitebait), and the former differed significantly from all the other populations. The main fatty acids predominating in the liver of galaxiids from landlocked (Lake Bullen Merri) and estuarine populations were 16:0, 22:6(n-3) and 18:1 (n-9), and generally reflected the corresponding pattern in muscle. A principal component analysis of the fatty acid composition of muscle samples confirmed and highlighted the distinct fatty acid profile of the populations investigated, when three groupings could be discerned. The study suggests that in addition to the diet, other habitat related factors may influence the fatty acid profile in catadromous G. maculatus.  相似文献   

17.
试验以300尾初始体重为(44.40±0.41)g的吉富罗非鱼(GIFT,Oreochromis niloticus)为研究对象,分别饲喂用蚕蛹(SP)替代0、25%、50%、75%和100%鱼粉(FM)的5种等氮(32%)等脂(5.5%)的饲料(分别命名SP0、SP25、SP50、SP75和SP100,基础饲料中含8%的鱼粉),每组3重复,每重复20尾鱼,在室内循环水养殖系统进行为期8周的生长试验,旨在探讨蚕蛹替代鱼粉对吉富罗非鱼肌肉营养成分的影响。结果表明:随蚕蛹替代水平上升,吉富罗非鱼肌肉粗蛋白、灰分、总氨基酸、必需氨基酸显著下降,肌肉粗脂肪含量无显著差异;较SP0组,SP100组肌肉总氨基酸和必需氨基酸分别下降3.99%和3.46%。随蚕蛹替代量增加,吉富罗非鱼肌肉C18∶3n-3和C20∶5n-3显著上升,C18∶2n-6显著下降;SP100组吉富罗非鱼肌肉C18∶3n-3和C20∶5n-3较SP0组分别上升105.33%和132.72%。结论:蚕蛹替代鱼粉后显著提高了吉富罗非鱼肌肉C18∶3n-3和C20∶5n-3含量,有利于生产富含n-3PUFA的鱼肉产品。  相似文献   

18.
Monounsaturated fatty acids (MUFA)-rich and n-6 polyunsaturated fatty acid (n-6 PUFA)-rich vegetable oils are increasingly used as fish oil replacers for aquafeed formulation. The present study investigated the fatty acid metabolism in juvenile European sea bass (Dicentrarchus labrax, 38.4 g) fed diets containing fish oil (FO, as the control treatment) or two different vegetable oils (the MUFA-rich canola/rapeseed oil, CO; and the n-6 PUFA-rich cottonseed oil, CSO) tested individually or as a 50/50 blend (CO/CSO). The whole-body fatty acid balance method was used to deduce the apparent in vivo fatty acid metabolism. No effect on growth performance and feed utilization was recorded. However, it should be noted that the fish meal content of the experimental diets was relatively high, and thus the requirement for n-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) may have likely been fulfilled even if dietary fish oil was fully replaced by vegetable oils. Overall, relatively little apparent in vivo fatty acid bioconversion was recorded, whilst the apparent in vivo β-oxidation of dietary fatty acid was largely affected by the dietary lipid source, with higher rate of β-oxidation for those fatty acids which were provided in dietary surplus. The deposition of 20:5n-3 and 22:6n-3, as % of the dietary intake, was greatest for the fish fed on the CSO diet. It has been shown that European sea bass seems to be able to efficiently use n-6 PUFA for energy substrate, and this may help in minimizing the β-oxidation of the health benefiting n-3 LC-PUFA and thus increase their deposition into fish tissues.  相似文献   

19.
Muscle proximate composition, amino acid profiles, fatty acid compositions and selected minerals of wild, pond and factory cultured Japanese flounder adults were compared in this study to elucidate their nutritive values and dietary nutrition requirements. Wild and pond cultured Japanese flounder flesh had higher crude proteins, but crude lipid contents of factory cultured fish were 3.8~4.0 fold greater. Major amino acids in Japanese flounder were aspartic acid, glutamic acid and lysine. Wild fish had higher levels of total amino acids, essential amino acids, nonessential amino acids and half‐essential amino acids and the contents in pond cultured samples were similar. Arachidonic acids (ARA), eicosapentaenoic acids (EPA), docosahexaenoic acids (DHA), polyunsaturated fatty acids (PUFA), DHA + EPA and n–3 PUFA in wild Japanese flounder were significantly higher than that in factory cultured fish, whereas fatty acid levels were close between pond cultured and wild fish. Japanese flounder were rich in zinc, iron and selenium, but poor in copper, chromium and nickel. Results indicated wild Japanese flounder had higher nutritional value and better meat quality, but the nutritional compositions of pond cultured fish were close to wild Japanese flounder, which suggested that pond culture of Japanese flounder offers broad application prospects.  相似文献   

20.
Rainbow trout (Oncorhynchus mykiss) skin cell cultures were obtained by trypsinization of the tissue and grown in Leibovitz L-15 medium. Lipid class compositions, and fatty acid profiles of total lipids and individual phospholipid classes were determined at different times of culture. The metabolism of polyunsaturated fatty acids (PUFA) was investigated by incubating primary cultures after 7 and 14 days with [1-14C]18:2n-6 and [1-14C-]18:3n-3. The change in morphology between epithelial-like primary cultures and fibroblastic-like secondary subcultures was accompanied by alterations in the lipid composition. Polar lipids became predominant by 14 days in culture. The relative proportions of phosphatidylcholine (PC), the most abundant phospholipid, phosphatidylinositol and cholesterol increased significantly, while sphingomyelin decreased. Saturated fatty acids, 18:1n-9, n-6 and n-9PUFA were more abundant in total lipid in cultures at 14 days and 4 months than in cells initially isolated which contained higher percentages of longer chain monoenes and n-3PUFA. The changes in fatty acid composition with time in culture were observed in all the major phospholipid classes. Rainbow trout skin cells in culture desaturated and elongated both 18:2n-6 and 18:3n-3, with 20:4n-6 and 20:5n-3 being the most abundant products, respectively. PC presented the highest incorporation of radioactivity, especially following incubation with 18:3n-3. Lipid metabolism in general increased with the age of primary cultures, with both the amount of C18 PUFA incorporated and metabolized by desaturation/elongation significantly increased in 14 day cultures compared to 7 day cultures. Product/precursor ratios calculated for both n-6 and n-3 fatty acids showed that, while 6 desaturase activity was increased significantly with cell age, 5 desaturase activity was more affected by the fatty acid series, with 18:3n-3 being more readily transformed to 20:5n-3 than 18:2n-6 to 20:4n-6. Further desaturation of 20:5n-3 to hexaenes was low. Overall, the data suggested that the trout skin cell cultures were more similar to mammalian skin fibroblasts than mammalian epidermal/keratinocyte cultures.  相似文献   

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