鲣鱼、金枪鱼眼窝内DHA含量高

近年,中上层鱼类中含量多的高度不饱和脂肪酸中的DHA生理活性高而引入关注,鲣鱼金枪鱼类的眼窝脂肪中的高度不饱和脂肪酸含量为30—40％,并含有丰富的DHA。尽管沙丁鱼、鲐鱼油中含有5—10％的DHA,但同时具有类似化学构造的EPA含量则为10—     

鲣鱼的利用探索

鲣鱼,属鲈形总目、金枪鱼亚目、金枪鱼科、舵鲣亚科、鲣属,我国只产一种,别名柴鱼、鲔鱼。鲣鱼肉呈红色,蛋白质含量高,可鲜食。因其鱼脂含量低(鲜态为1%～5%),目前国内常加工为鱼干型产品,加工过程中产生大量废弃物—鲣鱼头等,而鲣鱼头中含有可利用的蛋白质等物质。     

浅谈鱼油的酸价与过氧化值

随着鱼粉加工业的发展及人们对鱼油中诸多不饱和脂肪酸医药性质的研究，开发和利用鱼油、生产优质鱼油已是水产加工企业的重要任务，而鱼油作为一种新的产品，将逐渐由鱼粉生产中的副产品转为主产品，其潜在的利用价值已逐渐超过鱼粉c在鱼油的加工、生产、储存过程中，生产者最难掌握的是酸价与过氧化值的含量，而此两项指标的高低又恰是评定鱼油质量的重要指标。那么问为酸价、过氧化值呢？酸价是指游离脂肪酸的含量；过氧化值是指油脂氧化过程中产生过氧化物的含量。鱼油因其富含高度不饱和脂肪酸而具重要价值，但所含的高度不饱和脂肪酸…     

草鱼内脏鱼油乙醇提取研究及其脂舫酸组成分析

对无水乙醇提取草鱼内脏鱼油工艺进行了研究,并分析了鱼油的基本理化性质和脂肪酸组成,主要研究了料液比对鱼油提取率的影响。无水乙醇提取草鱼内脏鱼油的工艺为:料液比(w:v)1:8,提取温度55℃,提取时间3小时。在此工艺条件下,粗鱼油提取率为87.6%。粗鱼油经85%磷酸脱胶、4%NaOH脱酸、活性白土脱色后,鱼油呈浅黄色透明状,酸价、过氧化值较低;经冬化处理后的鱼油中不饱和脂肪酸含量约为81.5%。     

水产加工副产物中磷脂和鱼油的分离及脂质组学研究

为更好地对水产加工副产物进行加工利用,本实验建立了从水产加工副产物中同时提取制备磷脂和鱼油的方法,并分别利用多维度串联质谱鸟枪法和气相色谱法对样品的磷脂和鱼油的脂肪酸化合物进行脂质组学研究。利用改进Folch法和丙酮沉淀法制备得到副产物中的磷脂和鱼油,比较了5种不同萃取液的提取效率,其中CH2Cl2-Me OH(1∶2,V/V)混合液同时提取磷脂和鱼油效果最佳,提取率分别为0.97%和28.05%。鱼油经甲酯化反应,以正己烷为溶剂直接进样,利用气相色谱法分析脂肪酸甲酯成分,磷脂样品采用流动注射直接进样,经三重四级杆质谱母离子扫描(Pre IS)和中性质量丢失扫描(NLS)对磷脂分子实现源内分离鉴定和定量分析。结果显示,鱼油中主要含有油酸、亚油酸、棕榈酸等23种脂肪酸,其中不饱和脂肪酸占75.97%;磷脂样品中共检出磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰肌醇和磷脂酰丝氨酸4类共69种磷脂分子,并测出了许多含有DHA、EPA链的磷脂,如16∶0/20∶5、16∶0/22∶6、18∶1/22∶6、18∶0/22∶6、20∶0/22∶6等。研究表明,该方法能同时提取磷脂和鱼油,并且前处理简单、提取效率高,能够实现对资源的合理利用。     

提取方法对淡水鱼油提取率及品质的影响

以白鲢(Hypophthalmichthys molitrix)内脏为原料,采用复合蛋白酶(Protemax)水解法提取鱼油,研究酶解条件和提取方法对鱼油提取率、品质及脂肪酸组成的影响,以获取高品质的鱼油制品.结果表明:提取方法和条件对鱼油的提取率、酸价及过氧化值(POV)均有明显影响;采用复合蛋白酶水解法提取鱼油时,其适宜的条件为酶解起始pH 7.5,酶解温度50 ℃,酶用量2 000 U/g粗蛋白,酶解时间3 h,鱼油的提取率达到85.67%,鱼油品质较好.复合蛋白酶水解法和碱性蛋白酶(Alcalase)水解法的提取率高于稀碱水解法,且复合蛋白酶水解法得到的n-3系列多不饱和脂肪酸含量更高.     

日本将综合利用鰤鱼废弃物

日本爱媛县水产试验场为了提高养殖鰤鱼的附加效益，从1989年开始将进行“鱼类废弃物综合利用”的研究。从生鱼片加工时产生的废弃物中提取能预防脑血栓的高不饱和脂肪酸，应用于保健食品及医药中，同时提取钙和维生素，应用于鱼类养殖的饲料和食品添加剂等方面。     

日本将综合利用(鱼师)鱼废弃物

<正> 日本爱媛县水产试验场为了提高养殖(鱼师)的附加效益,从 1989年开始将进行“鱼类废弃物综合利用”的研究。从生鱼片加工时产生的废弃物中提取能预防脑血栓的高不饱和脂肪酸,应用于保健食品及医药中;同时提取钙和维生素,应用于鱼类养殖的饲料和食品添加剂等方面。     

鲢鱼肌肉脂肪酸分离方法效果比较及组成特征分析

采用3种不同方法,即超声波提取法、索氏提取法和氯仿-甲醇法,从鲢鱼肌肉中提取鱼油,继而进行酸性和碱性甲酯化,经气相色谱/质谱联用技术,对其脂肪酸组成特征进行了定性和定量分析.结果表明,鲢鱼肌肉含有25种脂肪酸,其中包括7科饱和脂肪酸.8种单不饱和脂肪酸和10种多不饱和脂肪酸.3种分离方法间存在明显分离效果差异,所获得不饱和脂肪酸含量占总脂肪酸含量分别为41.39%、36.15%和3355%.     

鱼油的提取与精制技术探讨

利用水产加工下脚料提取鱼油并进行精制.探讨了湿法工艺提取鱼油和精炼的工艺,比较了不同脱酸工艺对产品质量的影响,介绍了白土脱色和活性碳脱色工艺条件,并对冬化和脱臭工艺进行了研究.     

Dietary utility of enzyme-treated fish meal for juvenile Pacific bluefin tuna <Emphasis Type="Italic">Thunnus orientalis</Emphasis>

ABSTRACT:   In order to develop an artificial diet, the dietary utility of enzyme-treated fish meal was investigated for juvenile Pacific bluefin tuna Thunnus orientalis (PBT). Diets containing each 63% of Chilean fish meal (FM), enzyme-treated Chilean fish meal (EC) and enzyme-treated Peruvian fish meal (EP), with 10% bonito oil and raw sand lance Ammodytes personatus (SL) were fed to juvenile tuna six times per day for one week. In a different trial, diets EC and SL were fed to tuna six times per day for 2 weeks. Only diet EC sustained similar growth or caused lower survival and higher feed efficiency, hepato- and enterosomatic indices and final carcass lipid content as compared to those of SL. Diets FM and EP led to lower specific growth rate (SGR) but similar feed efficiency, survival and hepatosomatic index, yet higher enterosomatic index. Moreover, PBT fed diet EC for 2 weeks led to similar growth performance but higher final carcass and hepatic lipid contents, and plasma cholesterol and phospholipid levels than those fed SL. Carcass fatty acid composition of diet EC group had lower 20:5  n -3 and 22:6  n -3 levels than the SL group. These results revealed that EC, as a suitable dietary protein source, could sustain growth of PBT, while dietary bonito oil led to higher carcass lipid but lower accumulation of n -3 highly unsaturated fatty acids.     

Enhancing highly unsaturated ω‐3 fatty acids in phase‐fed rainbow trout (Oncorhynchus mykiss) using Alaskan fish oils

Rainbow trout, average weight 185–187 g, were fed feeds containing menhaden oil, canola oil or fish oils (pollock, pink salmon or rockfish) produced from Alaskan seafood processing waste as the added oil for 8 weeks, at which time the fish weighed 391–411 g (average 404 g, pooled SE = 5.7). The fish were previously fed from 75 g average weight fed commercial feed containing poultry oil as the added oil. No significant differences were measured in final weight or feed conversion ratio among dietary treatment groups. Significant differences were found in fillet ω‐3 fatty acid (FA) levels from fish receiving fish oil‐supplemented feeds compared to those from fish receiving feeds containing canola oil. Fillet contents of eicosapentaenoic acid (EPA; 20:5ω3) and decosahexaenoic acid (DHA; 22:6ω3) were highest in the pollock oil treatment group, although all fish oils increased highly unsaturated ω‐3 FA contents (mg 100 g^?1) of fillets. Fish oil used through the production cycle was reduced by 25% by supplementing feeds with poultry oil during the middle phase of production (75–175 g) compared to using feeds containing fish oil throughout the production cycle. Fish oils recovered from Alaskan seafood processing waste were suitable alternatives to conventional fish oil as ingredients in rainbow trout production feeds.     

Comparison of the lipid profiles from wild caught eggs and unfed larvae of two scombroid fish: northern bluefin tuna (<Emphasis Type="Italic">Thunnus thynnus</Emphasis> L., 1758) and Atlantic bonito (<Emphasis Type="Italic">Sarda sarda</Emphasis> Bloch, 1793)

Lipids and essential fatty acids are determinants of the reproductive process in marine fish, affecting fecundity, egg quality, hatching performance, pigmentation and larval malformation. We have analyzed and characterized the lipids of eggs and unfed larvae of two wild caught scombroid fish, the Atlantic northern bluefin tuna (Thunnus thynnus) and Atlantic bonito (Sarda sarda). Dry matter and total lipid contents, polar and neutral lipid classes and total lipid fatty acid contents were determined in the eggs of bluefin tuna and eggs and unfed larvae during the development of Atlantic bonito. Bluefin tuna eggs had slightly but significantly more dry mass than bonito eggs but very similar lipid content. However, bluefin tuna eggs presented a higher polar lipid content due to increased proportions of phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI). Bonito eggs and larvae showed increasing dry mass and decreasing lipid content with development. The proportion of polar lipids increased due to increased PE, PS and PI, whereas choline-containing polar lipids (phosphatidylcholine and sphingomyelin) remained relatively constant. Free cholesterol also increased, whereas the levels of other neutral lipids, especially triacylglycerol and steryl ester fractions, decreased, presumably due to utilization for energy to drive development. Bluefin tuna eggs had higher levels of n − 3 and n − 6 highly unsaturated fatty acids due to higher docosahexaenoic and arachidonic acid contents, respectively, than bonito eggs. The results are discussed in relation to the lipid and fatty acid requirements of larval scombroid fish in comparison to those of other larval marine finfish species under culture conditions.     

Comparison of effects of vegetable oils blended with southern hemisphere fish oil and decontaminated northern hemisphere fish oil on growth performance, composition and gene expression in Atlantic salmon (Salmo salar L.)

Replacement of fish oil with sustainable alternatives, such as vegetable oil, in aquaculture diets has to be achieved without compromising the nutritional quality, in terms of n-3 highly unsaturated fatty acid (HUFA) content, of the product. This may be possible if the level of replacement is not too high and oil blends are chosen carefully but, if high levels of fish oil are substituted, a fish oil finishing diet prior to harvest would be required to restore n-3HUFA. However, a decontaminated fish oil would be required to avoid increasing undesirable contaminants. Here we test the hypotheses that blending of rapeseed and soybean oils with southern hemisphere fish oil will have a low impact upon tissue n-3HUFA levels, and that decontamination of fish oil will have no major effect on the nutritional quality of fish oil as a feed ingredient for Atlantic salmon. Salmon (initial weight ~ 0.8 kg) were fed for 10 weeks with diets in which 60% of fish oil was replaced with blends of soybean, rapeseed and southern hemisphere fish oil (SVO) or 100% decontaminated northern fish oil (DFO) in comparison with a standard northern fish oil diet (FO). Decontamination of the oil was a two-step procedure that included treatment with activated carbon followed by thin film deodorisation. Growth performance and feed efficiency were unaffected by either the SVO or DFO diets despite these having lower gross nutrient and fatty acid digestibilities than the FO diet. There were also no effects on the gross composition of the fish. Liver and, to a lesser extent flesh, lipid levels were lower in fish fed the SVO blends, due to lower proportions of neutral lipids, specifically triacylglycerol. Tissue lipid levels were not affected in fish fed the DFO diet. Reflecting the diet, flesh eicosapentaenoic acid (EPA) and total n-3 fatty acids were higher, and 18:1n-9 lower, in fish fed DFO than FO, whereas there were no differences in liver fatty acid compositions. Flesh EPA levels were only slightly reduced from about 6% to 5% although docosahexaenoic acid (DHA) was reduced more severely from around 13% to about 7% in fish fed the SVO diets. In contrast, the liver fatty acid compositions showed higher levels of n-3 HUFA, with DHA only reduced from 21% to about 18% and EPA increased from under 8% to 9–10% in fish fed the SVO diets. The evidence suggested that increased liver EPA (and arachidonic acid) was not simply retention, but also conversion of dietary 18:3n-3 and 18:2n-6. Increased HUFA synthesis was supported by increased hepatic expression of fatty acyl desaturases in fish fed the SVO diets. Flesh n-3HUFA levels and desaturase expression was significantly higher in fish fed soybean oil than in fish fed rapeseed oil. In conclusion, partial replacement of fish oil with blends of vegetable oils and southern hemisphere fish oil had minimal impact on HUFA levels in liver, but a greater effect on flesh HUFA levels. Despite lower apparent digestibility, decontamination of fish oil did not significantly impact its nutritional quality for salmon.     

高不饱和脂肪酸（HUFAs）在淡水鱼类中的营养作用研究进展

鱼粉、鱼油资源的短缺促使全球水产养殖业积极寻找其替代原料,而探究鱼粉、鱼油与其替代物之间的差异尤为重要,其中最主要的差异就是高不饱和脂肪酸(highly unsaturated fatty acids,HUFAs)是否存在及其含量多少。HUFAs是一类碳原子数目≥20、双键数≥3的脂肪酸,具有为动物提供能量、构成细胞膜组分、形成高生物活性物质、调控脂质代谢和免疫功能等重要作用,主要存在于鱼油和某些类别的微藻中。淡水鱼类具备自身合成HUFAs的能力,因此,一般认为HUFAs不是淡水鱼类的必需脂肪酸,无需通过饲料提供。但已有研究指出,饲料中添加一定量的HUFAs能够对淡水鱼类产生积极的营养作用,表明淡水鱼类的脂肪酸营养理论尚需进一步完善。本文综述了HUFAs在淡水鱼类生长、脂质代谢、健康免疫、繁殖特性等方面发挥作用的相关研究结果,明确提出淡水鱼类需要摄取一定水平的外源性HUFAs,指出在当前淡水鱼饲料中普遍使用HUFAs相对缺乏的蛋白源和油脂源的背景之下,HUFAs对淡水鱼类的作用应受到关注。最后,本文对今后淡水鱼类HUFAs营养的研究方向,以及新的HUFAs油脂源的开发前景进行了展望。     

Influence of dietary phospholipids on early ontogenesis of fish

The aim of this paper is to provide explanations of how dietary phospholipid (PL) globally improves fish larval development, including growth and survival, digestive functions and skeletal development, and to propose optimal PL levels and sources in fish larval diets. Dietary incorporation of 8–12% PL related to dry matter (d.m.) promotes growth and enhanced survival in various species. Marine source PL, incorporating highly unsaturated fatty acids, was most efficient than soybean lecithin. This beneficial effect was explained by an enhancement in digestive functions, assessed by digestive enzyme activities and histomorphology. Nevertheless, 1.5–2.5% highly unsaturated fatty acids related to diet d.m. supplied by PL improved growth, survival and skeletal development, while 5% induced different skeletal deformities. The high incidence of deformities was associated with the down-regulation of genes involved in development, such as RXRα, RARα, RARβ and BMP-4, observed in the early stages in larvae fed a high highly unsaturated fatty acids level.     

鱼油在不同体系中的氧化稳定性

以过氧化植（ＰＯＶ）、共轭二烯型氢过氧化物含量和脂肪酸相对含量的变化为指标研究了鱼油在不同体系中的氧化稳定性。结果表明：在贮藏过程中以Ｎ２保护的鱼油氧化稳定性最高,而暴露于空气中的鱼油的氧化稳定性最差。将鱼油分散于水中形成Ｏ／Ｗ型的乳化体系能提高鱼油的氧化稳定性。在三种体系中高不饱和脂肪酸的含量均比低不饱和脂肪酸下降的更快。隔绝Ｏ２是防止鱼油氧化的重要措施。     

Effect of expanded feed with high fish oil content on growth and fatty acid composition of rainbow trout

Rainbow trout (Oncorhynchus mykiss) were fed three different diets for 110 days — a basal dry diet with 8.4% oil content (BD8), a basal dry diet with 11.1%; oil content (BD11) a nd an expanded diet with 20.7% oil content (ED) — to investigate the influence of high fish oil exp anded diet on fatty acid composition of muscle, and to evaluate nutritional properties of edible tissue. I n fact, the experimental diets were also different in their component fatty acids, with an in creasing content of 3 highly unsaturated fatty acids (3 HUFA) from BD8 to ED. As regards biomet rics data, the condition factor and the coefficient of fatness were higher in fish fed ED in com parison with groups BD8 and BD11 (p < 0.05 ED vs. BD8). On the other hand, hepatosomatic index in group ED was markedly lower than those in groups BD8 and BD11 (p < 0.05 ED vs. BD8 and E D vs. BD11). This could be explained by the lower amount of crude protein in ED or it may indicate an excess amount of essential fatty acids (EFA) in ED. As regards fatty acid composition of fish m uscle, there were only slight differences in fatty acid composition of the edible tissue of fish wh en compared with the differences in fatty acid composition of the diets. The increased amount of fish oil in ED had a positive influence on the final weight of fish (p < 0.05 ED vs. BD8 and ED vs. BD11), but did not affect proportionately the percentage of 3 HUFA (20:53, 22:53, 22:63) and therefore the derived indices of lipid quality: so it appears possible to partially substitute fish oil in the diet with other lipid as a source of dietary fat.     

Effects of dietary lipid level and vegetable oil on fatty acid metabolism in Atlantic salmon (Salmo salar L.) over the whole production cycle

Changes in fatty acid metabolism in Atlantic salmon (Salmo salar) induced by vegetable oil (VO) replacement of fish oil (FO) and high dietary oil in aquaculture diets can have negative impacts on the nutritional quality of the product for the human consumer, including altered flesh fatty acid composition and lipid content. A dietary trial was designed to investigate the twin problems of FO replacement and high energy diets in salmon throughout the entire production cycle. Salmon were grown from first feeding to around 2 kg on diets in which FO was completely replaced by a 1:1 blend of linseed and rapeseed oils at low (14–17%) and high (25–35%) dietary oil levels. This paper reports specifically on the influence of diet on various aspects of fatty acid metabolism. Fatty acid compositions of liver, intestinal tissue and gill were altered by the diets with increased proportions of C₁₈ polyunsaturated fatty acids and decreased proportions of n-3 highly unsaturated fatty acids (HUFA) in fish fed VO compared to fish fed FO. HUFA synthesis in hepatocytes and enterocytes was significantly higher in fish fed VO, whereas β-oxidation was unaltered by either dietary oil content or type. Over the entire production cycle, HUFA synthesis in hepatocytes showed a decreasing trend with age interrupted by a large peak in activity at seawater transfer. Gill cell prostaglandin (PG) production showed a possible seasonal trend, with peak activities in winter and low activities in summer and at seawater transfer. PG production in seawater was lower in fish fed the high oil diets with the lowest PG production generally observed in fish fed high VO. The changes in fatty acid metabolism induced by high dietary oil and VO replacement contribute to altered flesh lipid content and fatty acid compositions, and so merit continued investigation to minimize any negative impacts that sustainable, environmentally-friendly and cost-effective aquaculture diets could have in the future. Abbreviations: FO - fish oil; HUFA - highly unsaturated fatty acids acids (carbon chain length ≥C ₂₀ with ≥3 double bonds); LO - linseed oil; RO - rapeseed oil; VO - vegetable oil. This revised version was published online in July 2006 with corrections to the Cover Date.