酶解法提取鱼油的工艺参数优化

利用蛋白酶酶解法从黄鳍金枪鱼(Thunnus albacares)加工的下脚料———鱼头中提取鱼油。以鱼油提取率和感官特征为指标,通过正交优化实验设计,获得了胰蛋白酶提取鱼油的最佳酶解工艺参数:酶解温度45℃,酶添加量1.5%,料液质量比1∶1,酶解时间4 h,酶解pH 8。在该条件下,鱼油的提取率为4.34%,理化指标除过氧化值外均达到SC/T3502-2000的粗鱼油二级标准,多不饱和脂肪酸总含量高达38.47%,其中DHA和EPA的含量分别为23.63%和4.84%。     

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%。     

酶解法提取鱼油的工艺参数优化

利用蛋白酶酶解法从黄鳍金枪鱼（Thunnus albacares）加工的下脚料——鱼头中提取鱼油。以鱼油提取率和感官特征为指标，通过正交优化实验设计，获得了胰蛋白酶提取鱼油的最佳酶解工艺参数：酶解温度45℃，酶添加量1．5％．料液质量比1：1，酶解时间4h，酶解pH8。在该条件下．鱼油的提取率为4．34％，理化指标除过氧化值外均达到SC／T3502-2000的粗鱼油二级标准。多不饱和脂肪酸总含量高达38．47％,其中DHA和EPA的含量分别为23．63％和4．84％。     

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。     

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：800g，L的H3PO4脱胶，添加量为油量的1％（体积分数）；300g／L的Na0H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15min。经过精炼，鱼油呈淡黄色，澄清透明，有淡鱼腥昧，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％。     

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(PUFA)，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60min，硝酸银浓度为4mol／L时得到的产品得率为18．03％，浓缩产品中的EPA和DHA的质量分数分别为9．78％和86．07％，总质量分数达95．85％，过氧化值为7．35mmol／kg，碘值2608．9g／kg。     

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。     

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05、0、2505、00 mg/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500 mg/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。     

凤鲚、湖鲚和刀鲚卵巢氨基酸、脂肪酸及矿物元素分析

对长江下游凤鲚、湖鲚和刀鲚卵巢氨基酸、脂肪酸和矿物元素组成及含量进行了测定分析。结果表明:三种鲚属鱼类卵巢鲜样中总氨基酸、必需氨基酸、呈味氨基酸含量差异不显著;必需氨基酸含量(w)为5.36%～6.32%,占总氨基酸含量为:0.43%、0.41%和0.43%,均以亮氨酸含量最高而色氨酸最低,赖氨酸含量(w)为0.96%～1.04%;饱和脂肪酸、单不饱和脂肪酸和多不饱和脂肪酸差异较显著,脂肪酸组成均以油酸含量最高,EPA和DHA总量(w)为8.00%～11.81%;矿物质含量大多也存在显著差异,常量元素含量最高的为钾(16970～22220mg/kg),微量元素则为锌(262.0～277.0mg/kg);不同水域生长环境对鲚属鱼类卵巢氨基酸含量影响不显著,而对脂肪酸和矿物质含量影响较显著。     

珍珠龙胆石斑鱼肌肉营养成分与挥发性风味成分的分析与评价

【目的】分析珍珠龙胆石斑鱼背、腹部肌肉的营养成分与挥发性风味成分。【方法】采用顶空固相微萃取与气相色谱-质谱联用技术检测鱼肉挥发性风味物质,用常规分析法检测鱼肉氨基酸及脂肪酸组成。【结果】珍珠龙胆石斑鱼含肉率达到71.03%±3.88%,鱼鳞与皮质量分数高达9.60%±1.67%。背、腹部肌肉的蛋白质质量分数(干基)分别为85.19%和77.47%,脂肪质量分数分别为6.44%和12.00%,必需氨基酸占总氨基酸质量分数均为0.45;背、腹部肌肉第一限制性氨基酸均为缬氨酸,氨基酸评分(AAS)分别为86和81,氨基酸指数分别为80.06和72.61,均为赖氨酸含量最高,氨基酸评分(AAS)分别为156和140;背部肌肉中5种鲜味氨基酸总量(7.26%)较腹部(7.09%)略高,不饱和脂肪酸分别占肌肉脂肪酸总量的60.11%和45.54%,EPA+DHA的含量是腹部肌肉的11.5倍,质量分数达20.42%,ω-3/ω-6 PUFA为9.56;背、腹部肌肉分别检出挥发性风味物质50与52种,腹部肌肉中醇类物质含量最高,质量分数达60.25%,其不饱和醇类与醛类对其肌肉的总体风味起重要贡献。【结论】珍珠龙胆石斑鱼是一种高蛋白、低脂肪、富含赖氨酸、精氨酸、EPA和DHA的优质海产经济鱼种,其背部肌肉蛋白质营养价值高于腹部,是优质的ω-3不饱和脂肪酸的食物来源;背、腹部肌肉挥发性风味物质含量丰富,腹部肌肉的鲜味优于背部肌肉。     

~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.     

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.     

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。     

EFFECT OF ARTIFICIAL REGULATIONS OF ARTEMIA n-3 HUFA CONTENT ON GROWTH AND SURVIVAL OF BLACK SEABREAM (SPARUS MACROCEPHLUS) LARVAE

ImODUCTIONStudiesonthenutritionmpuirementSoffishlarvaehavernadesomeprognaabroad,butwearenotawareofreportSonsuchstudiesinChinanow.ltwasdeter-Annedanhythatn-3HU-FA,espedally22f6(n-3)roHA)and2O5(n-3)(EPA)ises-sentialformarinefishlarvaegroWth.ThehighcontentofDHAinmarinefisheggSandthel0wcontent0fDHAinArtrmiashowthatArthetaasliwfndcandsaoothen-3HUFAreq~dmendfishlacae.bosdenistSdriitaln-3HUFAenriedArbotabyboingthemn-3HUFAcontainingbogtanulataldietS,etC.Watanabe,T.(l983)enri~livefe…     

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.     

Screening on DHA-producing Antarctic bacteria N- 6 and its cultural conditions

1 IntroductionPolyunsaturated fatty acids (PUFAs) have remained as a natural product due to thesynthetic difficulty of reproducing the methylene interrupted double bond sequence by in-dustrial chemistry. Their significance to animals and humans lies in th…