维生素E醋酸酯对鱼油脂肪酸含量变化的影响

新鲜鱼油中添加0、50、250、500mg／kg 4种不同浓度的维生素E醋酸酯，在实验的第6、14、28、36和68天测定鱼油中的脂肪酸含量。结果表明：在500mg/kg添加量内，维生素E醋酸酯对鱼油中脂肪酸含量没有显著性影响（P〉0．05）。在实验期间，EPA（C20：5）、DHA（C22：6）、亚油酸（C18：2）含量明显下降，ARA（C20：4）、亚麻酸（C18：3）先升后降，棕榈酸（C16：1）逐步上升；C14含量逐渐增加，C17则先降后升，C16和C18在实验后期有较大提高。维生素E醋酸酯对鱼油中不饱和脂肪酸效用系数大小依次为：ARA〉EPA〉DHA〉C18：3〉0〉C16：1〉C18：2〉C18：1。对ARA抗氧化效用最大，效用系数达到10．193％，C20：5为0．490％，C22：6为0．364％；维生素E醋酸酯对饱和脂肪酸效用系数大小依次为：C14〉C17〉0〉C18〉C16。     

4个地理群体方格星虫脂肪酸及食物组成分析

【目的】探究方格星虫(Sipunculus nudus)脂肪酸组成特征,分析其食物组成。【方法】气相色谱-质谱联用法测定方格星虫4个地理群体(福建漳州海澄镇、广东湛江东海岛和遂溪草潭镇、广西北海沙虫寮村)体壁肌肉的脂肪酸含量,脂肪酸标记法分析其食物组成。【结果】4个地理群体方格星虫共检出30种脂肪酸。方格星虫饱和脂肪酸总含量(ΣSFA)和多不饱和脂肪酸总含量(ΣPUFA)较高,ΣSFA主要由C14:0、C16:0和C18:0所组成,ΣPUFA以EPA、DHA、C18:2n6和C20:4n6为主要成分;单不饱和脂肪酸总含量(ΣMUFA)较低,其中C18:1n9和C17:1n7贡献最大。方格星虫体壁脂肪酸呈现出多种饵料生物的脂肪酸标记物特征。【结论】方格星虫体壁脂肪酸种类丰富,不同地理群体间脂肪酸组成和相对含量存在明显差异。     

1龄刀鲚一般营养成分和脂肪酸组成

【目的】探索1龄刀鲚(Coilianasus)在池塘中不同养殖时期的营养价值和需求。【方法】2018年7月18日投放刀鲚,于7月26日起至11月1日每约30d取样1次,采用生化分析方法测定1龄刀鲚不同养殖时期鱼体的一般营养成分和脂肪酸组成。【结果】刀鲚鱼体水分质量分数为73.54%～80.55%,粗脂肪质量分数为1.42%～3.97%,粗蛋白质量分数为14.55%～16.13%,粗灰分质量分数为2.38%～2.99%。在不同养殖阶段的刀鲚鱼体中均检出28种C12―C24脂肪酸,分别为9种饱和脂肪酸(SFA)、7种单不饱和脂肪酸(MUFA)和12种多不饱和脂肪酸(PUFA)。SFA以C18:1n9c为主,其在总脂肪酸中占比均超过25%,PUFA以C18:2n6c和C18:3n3为主。SFA从53.98%逐渐降至32.65%,其中10月和11月SFA依次显著降低(P0.05)。PUFA在7-9月较低,10、11月分别显著增加至26.26%和28.71%。不饱和脂肪酸(UFA)从7月的45.86%依次显著增加到11月的67.35%(P0.05),主要与C18:3n3、 C20:2、 C20:5n3(EPA)、 C22:6n3(DHA)和C22:5n3(DPA)含量显著增加有关。∑n-3PUFA/∑n-6PUFA的比值先降后升,最小值为0.61,最大值为2.55。SFA的逐渐降低和UFA逐渐升高导致SFA、UFA的比值从1.18显著降低到0.48。【结论】1龄刀鲚粗蛋白含量相对稳定,粗脂肪含量较低。建议在1龄刀鲚养殖中增加活饵料的密度和适口饵料的种类,在饲料研发中提高饲料配方中粗脂肪含量并优化脂肪酸组成。     

尿素包合法富集蛇鲻鱼油中EPA和DHA的研究

以蛇鲻精制鱼油为原料,采用氢氧化钾乙醇皂化和硫酸酸化制备鱼油混合脂肪酸,以EPA和DHA含量为指标,探讨了尿素包合法富集鱼油中EPA和DHA的工艺条件。结果表明:以乙醇为溶剂,在尿脂质量比为2︰1和包合温度0℃的条件下进行一次性包合20 h后,富集产物中EPA和DHA总含量达到了69.74%,其中EPA含量为22.05%,DHA含量为47.69%,达到了保健鱼油的生产要求。     

金枪鱼鱼卵营养成分分析及营养评价

【目的】系统分析和评价金枪鱼鱼卵营养成分。【方法】利用气相色谱、氨基酸分析仪和电感耦合等离子体质谱(ICP-MS)法测定金枪鱼鱼卵脂肪酸、氨基酸和矿物质元素组成。【结果与结论】金枪鱼鱼卵水分质量分数为(68.76±0.35)%,粗蛋白质量分数为(21.00±0.06)%,粗脂肪质量分数为(7.10±0.12)%,粗灰分质量分数为(1.60±0.08)%。电感耦合等离子体质谱(ICP-MS)测得鱼卵中含有丰富的Mg、Ca、K、Na、Fe等金属元素。鱼卵中含有17种氨基酸,其中谷氨酸(Glu)含量最高,天冬氨酸(Asp)次之。鱼卵中含有7种必需氨基酸(色氨酸被水解),占氨基酸总量的40.17%;8种非必需氨基酸,占氨基酸总量的49.92%;必需氨基酸/非必需氨基酸为80.47%,必需氨基酸构成比例符合FAO/WHO关于理想蛋白源的标准。另外,鱼卵中有10种不饱和脂肪酸和5种饱和脂肪酸,分别占总脂肪酸含量的44.44%和51.56%。其中棕榈酸(C16:0)、硬脂酸(C18:0)和二十二碳六烯酸(DHA)为主要脂肪酸,三者之和占总脂肪酸含量的70.90%。鱼卵中磷脂含量丰富且不饱和脂肪酸种类多,可作为优质的脂肪酸来源。     

CONTENTS OF CARBOHYDRATES AND LIPIDS IN THE BODIES OF TWO PLANKTONIC CRUSTACEANS

The carbohydrate and lipid contents in two planktonic crustaceans, i. e. Pseudeuphausia sinica and Acetes chinensis sampled from Xiamen coastal waters were estimated. In P. sinica, the contents of carbohydrates (in dry weight)and lipids varied from 2.19-2.33% and 21.2-21.9 % respectively; in A. chinensis from 1. 74-2. 55% and 14. 43-15. 10% respectively. The analyses of fatty acids by gas-chromatograph (Model 103)showed that eight fatty acids of 14 : 0, 15 : 0 , 16 : 0, 17 : 0, 18 : 0, 18 : 2, 20 : 2 and 22 : 2 were found in these two animals, that 16 : 0,18 :0 ,18 :2 ,and 20 : 2 formed the major constituents with 91.08 % (P. sinica)and 74.80 % (A. chinensis) of the total fatty acids, and that the values of odd carbon types ( 15 : 0 and 17: 0) were fairly low, 4. 47% and 3. 36% respectively. Three monosaccharides : glucose, fructose, and galactose detected by high-liquid chromatograph (Waters 208) accounted for more than 60 % of the total carbohydrates, especially the glucose, exceeding by 40 %.     

硝酸银络合法浓缩金枪鱼鱼油多不饱和脂肪酸的研究

以金枪鱼鱼油混合脂肪酸为材料 ,利用硝酸银络合法浓缩其中的多不饱和脂肪酸 (PU FA) ,主要考察了搅拌时间和硝酸银浓度对产品得率和EPA和DHA含量的影响 ,并测定了产品的理化指标和脂肪酸组成。研究结果表明 :搅拌时间为 6 0min ,硝酸银浓度为 4mol/L时得到的产品得率为 18.0 3% ,浓缩产品中的EPA和DHA的质量分数分别为 9.78%和 86 .0 7% ,总质量分数达95 .85 % ,过氧化值为 7.35mmol/kg ,碘值 2 6 0 8.9g/kg。     

南海3种可食绿藻化学成分及其营养评价

对南海3种可食绿藻条浒苔（Erueromorpha clathrata）、石莼（Ulva lactuca L．）和总状蕨藻（Caulerpa racemoso）的主要化学成分进行了分析，结果显示：多糖、蛋白质和粗纤维是构成藻体的主要化学成分，占藻体的92％以上，其中膳食纤维占64．22％-70．80％；蛋白质占14．15％-18．91％，平均为16．16％。且蛋白质中必需氨基酸含量高，占总氨基酸的42．37％-48．37％，氨基酸评分在73分以上，第一限制氨基酸随藻种而变化；脂肪含量在0．51％-0．81％之间，均低于1％，多不饱和脂肪酸和必需脂肪酸含量高，其含量分别为其总量的56．10％。63．20％和37．71％-39．39％；矿物质和维生素含量丰富，尤其是Fe、Zn、I等矿质元素和维生素C含量高。3种可食绿藻是高膳食纤维，高蛋白，低脂肪，低热能，且富含矿物质和维生素的天然理想保健食品原料。     

点带石斑鱼幼鱼配合饲料的适宜能量蛋白比

以鱼粉和酪蛋白为蛋白源,添加鱼油、豆油、α-马铃薯淀粉、纤维素以及适量的维生素和矿物质配制成实验饲料,蛋白质质量分数设置41%、47%、53%3个水平,能量设置12 561、14 655、16 748 kJ/kg 3个水平,饲养点带石斑鱼幼鱼59 d后,以增重率、蛋白质效率、饲料系数为评价指标,分析不同能量蛋白比的饲料对点带石斑鱼体内消化酶活性的影响。结果表明:当能量蛋白比分别为31.30、33.50、32.26 kJ/g时,点带石斑鱼增重率、蛋白质效率达到极大值,饲料系数达到极小值;能量蛋白比在31.62～35.54 kJ/g范围内,胃、肠道的蛋白酶、淀粉酶、脂肪酶活性较强。点带石斑鱼幼鱼配合饲料中合适的能量蛋白比为31.62～33.50 kJ/g。     

The Response of Bio-Component Production of Nannochloris oculata to the Combinations of Monochromatic Light

Illuminating conditions are crucial factors affecting the microalgal growth and biosynthesis.The effects of illuminating spectral quality on the growth and bio-component production of Nannochloris oculata were investigated.The results indicated that a high proportion of Red-light enhanced the pigments and carbohydrate production but reduced those of the biomass and lipid.Mono-chromatic Blue-light has advantageous effects on lipid production compared with Red-and White-light.The optimal light spectrum for the protein production was the combination of Red-and Blue-light at a ratio of 4:3 or 5:2.Among the seven fatty acids identified from N.oculata,the contents of C16:0,C18:0,and C18:3(n-3)in the lipid were inhibited by the increased proportion of Red-light while those of C18:2(n-9),C16:2(n-6),and C20:0 were inhibited by Blue-light.Monochromatic Red-and Blue-light and their com-binations were proposed as a promising illuminating strategy for the large-scale cultivation aiming for various bio-components.     

Fatty acid composition of <Emphasis Type="Italic">Euphausia superba</Emphasis>, <Emphasis Type="Italic">Thysanoessa macrura</Emphasis> and <Emphasis Type="Italic">Euphausia crystallorophias</Emphasis> collected from Prydz Bay,Antarctica

The information of trophic relationship is important for studying the Southern Ocean ecosystems. In this study, three dominant krill species, Euphausia superba, Thysanoessa macrura and Euphausia crystallorophias, were collected from Prydz Bay, Antarctica, during austral summer of 2009/2010. The composition of fatty acids in these species was studied. E. superba and T. macrura showed a similar fatty acid composition which was dominated by C14:0, C16:0, EPA (eicosapentenoic acid) and DHA (decosahexenoic acid) while E. crystallorophias showed higher contents of C18:1(n-9), C18:1(n-7), DHA and EPA than the former two. Higher fatty acid ratios of C18:1(n-9)/18:1(n-7), PUFA (polyunsaturated fatty acid)/SFA (saturated fatty acid), and 18PUFA/16PUFA indicated that E. crystallorophias should be classified as a typical omnivore with a higher trophic position compared with E. superba and T. macrura.     

Fatty Acid Composition of Euphausia superba,Thysanoessa macrura and Euphausia crystallorophias Collected from Prydz Bay,Antarctica

The information of trophic relationship is important for studying the Southern Ocean ecosystems.In this study,three dominant krill species,Euphausia superba,Thysanoessa macrura and Euphausia crystallorophias,were collected from Prydz Bay,Antarctica,during austral summer of 2009/2010.The composition of fatty acids in these species was studied.E.superba and T.macrura showed a similar fatty acid composition which was dominated by C14:0,C16:0,EPA(eicosapentenoic acid) and DHA(decosahexenoic acid) while E.crystallorophias showed higher contents of C18:1(n-9),C18:1(n-7),DHA and EPA than the former two.Higher fatty acid ratios of C18:1(n-9)/18:1(n-7),PUFA(polyunsaturated fatty acid)/SFA(saturated fatty acid),and 18PUFA/16 PUFA indicated that E.crystallorophias should be classified as a typical omnivore with a higher trophic position compared with E.superba and T.macrura.     

Effects of calanoid copepod Schmackeria poplesia as a live food on the growth, survival and fatty acid composition of larvae and juveniles of Japanese flounder, Paralichthys olivaceus

Zooplankton constitutes a major part of the diet for fish larvae in the marine food web, and it is generally believed that copepods can meet the nutritional requirements of fish larvae. In this study, calanoid copepod Schmackeria poplesia, rotifer Brachionus plicatilis and anostraca crustacean Artemia sp. were analyzed for fatty acid contents, and were used as live food for culturing larval Japanese flounder, Paralichthys olivaceus. The total content of three types of HUFAs (DHA, EPA and ARA) in S. poplesia was significantly higher than that in the other two live foods (P<0.01). Three live organisms were used for raising larvae and juveniles of Paralichthys olivaceus respectively for 15 and 10 d. Then the growth, survival and fatty acid composition of the larvae and juveniles were investigated. The results showed that the larvae and juveniles fed with copepods (S. poplesia) had significantly higher growth rate than those fed with the other two organisms (P<0.01). The survival of the flounder larvae fed with copepods was significantly higher than that of the others (P<0.01), and the survival of the juvenile fish fed with copepods was higher than that fed with Artemia (P<0.05). The contents of three types of HUFAs (DHA, EPA and ARA) and the ratio of DHA/EPA in larval and juvenile flounder P. olivaceus were analyzed. The results showed that the contents of DHA, EPA and ARA in the larvae and juveniles fed with S. poplesia were higher than those fed with a mixed diet or Artemia only, and the ratio of EPA/ARA in larvae and juveniles of P. olivaceus fed with S. poplesia was lower than that in the case of feeding with a mixed diet or Artemia only. The present data showed that copepod is the best choice for feeding the larvae and juveniles of fish considering its effects on the survival, growth and nutrition composition of the fish.     

Lipid oxidation and fatty acid composition in salt-dried yellow croaker (<Emphasis Type="Italic">Pseudosciaena polyactis</Emphasis>) during processing

Lipid oxidation in salt-dried yellow croaker (Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value (POV), the thiobarbituric acid reactive substances (TBARS) value, and oxidative-relative lipoxygenase (LOX) activity. Additionally, fatty acids were analyzed using gas chromatography-mass spectrometry. Both POV and TBARS increased significantly (P < 0.05) at the rinsing stage. POV reached its peak value of 3.63 meq O₂ per kg sample at the drying stage, whereas TBARS constantly increased from 0.05 to 0.20 mg MDA per kg sample. Processing of salt-dried yellow croaker had an extremely significant (P < 0.01) effect on LOX activity. Twenty-six fatty acids were identified. Combined eicosapentaenoic acid (EPA; C20:5n3) and docosahexaenoic acid (DHA; C22:6n3) content varied between (19.20 ± 0.37) mg g^?1 and (23.45 ± 1.05) mg g^?1. The polyunsaturated fatty acid/saturated fatty acid (PUFA/SFA) ratio in yellow croaker was 0.73–1.10, and the n-6/n-3 PUFA ratio was approximately 0.13–0.20. The contents of most fatty acids varied significantly (P < 0.05) during the different processing stages, and these differences were caused by lipid oxidation. C18:0, C16:1n7, C19:0, and C22:6n3 showed clear changes in principle component one of a principle components analysis. These fatty acids are potential markers for evaluating lipid oxidation in fish muscle because there was a significant correlation between these markers and TBARS and LOX activity (P < 0.05) with Pearson’s coefficients > 0.931.     

A comparative analysis of fatty acid composition and fucoxanthin content in six <Emphasis Type="Italic">Phaeodactylum tricornutum</Emphasis> strains from diff erent origins

Phaeodactylum tricornutum is a potential livestock for the combined production of eicosapentaenoic acid (EPA) and fucoxanthin. In this study, six marine diatom strains identified as P. tricornutum were cultured and their total lipid, fatty acid composition and major photosynthetic pigments determined. It was found that the cell dry weight concentration and mean growth rate ranged between 0.24–0.36 g/L and 0.31–0.33/d, respectively. Among the strains, SCSIO771 presented the highest total lipid content, followed by SCSIO828, and the prominent fatty acids in all strains were C16:0, C16:1, C18:1, and C20:5 (EPA). Polyunsaturated fatty acids, including C16:2, C18:2, and EPA, comprised a significant proportion of the total fatty acids. EPA was markedly high in all strains, with the highest in SCSIO828 at 25.65% of total fatty acids. Fucoxanthin was the most abundant pigment in all strains, with the highest in SCSIO828 as well, at 5.50 mg/g. The collective results suggested that strain SCSIO828 could be considered a good candidate for the concurrent production of EPA and fucoxanthin.     

Comparative study of the nutritional composition and toxic elements of farmed and wild Chanodichthys mongolicus

Information of the difference in quality between farmed and wild fish is central to better ensuring fish products produced in aquaculture meet regulatory and consumer requirements.Proximate composition,amino acid and fatty acid profiles,and toxic elements contents of farmed and wild Chanodichthys mongolicus were established and compared.Significantly higher crude protein content while lower moisture content in farmed fish compared to wild fish were observed(P0.05).The percentages of total amino acids(TAA),total essential amino acids(TEAA),total non-essential amino acids(TNEAA)and total delicious amino acids(TDAA) in farmed fish were all significantly higher than those in the wild equivalent(PO.05).Compared to the FAO/WHO recommended reference values,the ratios of TEAA/TAA(39.84%-40.33%) were comparable to 40%and TEAA/TNEAA(66.22%-67.60%) were above 60%.Fatty acid profiles in both fanned and wild C.mongolicus were dominated by monounsaturated fatty acid(MUFA),with farmed fish contained much more MUFA content compared to wild counterpart(P0.05).Notably,wild fish exhibited significantly higher levels of total polyunsaturated fatty acid(PUFA) including eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) than farmed fish(P0.05).The EPA(C_(20:5n3))and linoleic acid(C_(18:2n6)) were the predominant PUFA in wild and fanned C.mongolicus,respectively.Moreover,farmed fish displayed an overall lower toxic element levels(As,Cd,Pb and Hg) in comparison with wild fish,and both were far lower than the established limit standard.In conclusion,our results suggest that the nutritional quality of farmed C.mongolicus was inferior to their wild counterpart with respect to fatty acids nutrition,and therefore further studies should focus on the improving C.mongolicus diet in order to enhance the overall nutritional composition.     

金枪鱼油的精炼工艺对脂肪酸组成的影响

粗鱼油通过精炼可以除去非甘油三酯杂质成分,研究表明黄鳍金枪鱼鱼油精炼的工艺参数为:800 g/L的H3PO4脱胶,添加量为油量的1%(体积分数);300 g/L的NaOH脱酸,添加量为油量的2%(体积分数);活性土脱色,添加量为油量的10%(质量分数);85℃下减压蒸馏脱臭15 min。经过精炼,鱼油呈淡黄色,澄清透明,有淡鱼腥味,理化指标达到鱼油SC/T3502-2000标准的精制鱼油一级要求,精制鱼油中PUFA的总含量(w)达37.06%,DHA和EPA含量(w)分别为25.10%和4.45%。     

~1H NMR Quantification of DHA and EPA in Fish Oil

Fish oil is a popular nutritional product consumed in China. The beneficial effects of fish oil have been attributed to docosahexaenoic acid(DHA) and eicosapentaenoic acid(EPA). Hence, it is crucial to develop a rapid and precise method to determine the contents of EPA and DHA in fish oil. In this study, a rapid and accurate proton nuclear magnetic resonance method for the quantification of DHA and EPA was developed. Dimethyl terephthalate was selected as an internal standard, and the signals at 2.391 ppm for DHA and at 1.697 ppm for EPA were chosen for the quantification. Validation of the method was performed in terms of specificity, precision, and stability. The results indicated that the method was precise and in line with the China Food and Drug Administration guidance. The method has been successfully applied to characterize fish oil capsules obtained from four pharmaceutical companies. This study indicated that the rapid ~1H NMR method is suitable for the quality control of fish oil.     

养殖海鲡肌肉的生化组成

对海鲡肌肉的营养成分含量及氨基酸、脂肪酸、无机质组成进行了研究，结果表明，海鲡的蛋白质和脂肪含量分别为21.5%和5.5%，必需氨基酸和鲜味氨基酸分别占氨基酸总量的40.9%和37.8%，不饱和脂肪酸占脂肪酸总量的65.2%，其中C205和C226的含量分别为4.5%和12.0%，3.4kg阶段的养殖海鲡肌肉的必需氨基酸和呈味氨基酸的比率最高。