尿素包合法富集鱼油中的EPA和DHA的研究

用尿素包合法（脲包法）对大连鱼油中的ＥＰＡ和ＤＨＡ进行富集，得到较佳操作条件为温度０℃，脲酯比１３，鱼油甲酯为脲包客体，以甲醇作溶剂。一次富集产品中（ＥＰＡ＋ＤＨＡ）浓度和收率分别达到６０％和９０％以上     

功能油脂EPA、DHA的开发及其保健性能

功能油脂ＥＰＡ、ＤＨＡ的开发及其保健性能张相年（广州军区总医院药局广州，５１００１０）一、前言近年来，有大量的文献报道ＥＰＡ、ＤＨＡ对人体的有益性。海鱼油富含的ｎ－３型脂肪酸ＥＰＡ、ＤＨＡ（即二十碳五烯酸、二十二碳六烯酸）是人体必需脂肪酸，具有良好的...     

国外对EPA和DHA的科研近况

本文对国外十十碳五烯酸（ＥＰＡ）和二十二碳六烯酸的近况做一扼要的报告。ＥＰＡ和ＤＨＡ原从海鱼油提取为主要来源，嗣以要求纯度较高以供医药之用，且为量逐渐增加，各国又转向合成法研究，现两种生产方式并存。本文除对ＥＰＡ和ＤＨＡ的效用做广泛的介绍外，对生产方式要点和最近发情况也示例地做了扼要的报告，最后还将欧洲共同体对医药用ＥＰＡ和ＤＨＡ有效组分的分析方法也提供了主要的文献。     

双液相萃取植物油脂和鱼油油脂的脂肪酸组成分析

通过把双液相萃取菜籽油和棉籽油的脂肪酸组成和市售油脂脂肪酸成份的对比，说明双液相工艺不改变油脂脂肪酸成分，海鱼鱼油中含有较高的二十碳五烯酸（ＥＰＡ）和二二碳六烯酸（ＤＨＡ），通过简单的物理方法，即可把ＥＰＡ＋ＤＨＡ含量富集到接近５０％。     

小麦谷蛋白亚基的凝胶电泳分离及其品种鉴定

小麦胚乳贮藏蛋白在去除醇溶蛋白后，再提取高分子量（ＨＭＷ）和低分子量（ＬＭＷ）谷蛋白亚基，然后采用酸性（ｐＨ３．１）聚丙烯酰胺凝胶电泳（Ａ－ＰＡＧＥ）方法进行分离。结果表明，在６００Ｖ电压下（缓冲液温度不超过２８℃），一般可在２～３ｈ内完成电泳，并可获得分辨度较高的分离图谱，在电泳谱上可发现两个明显的ＨＭＷ和ＬＭＷ谷蛋白亚基区域。通过与标准品种和常规ＳＤＳ－ＰＡＧＥ方法比较，可对不同品种ＨＭＷ谷蛋白亚基组成进行快速鉴定。一些重要小麦品种的分析结果显示，各品种ＬＭＷ谷蛋白亚基组成具有特异性，而且在品种间存在较大的变异度，根据ＨＭＷ和ＬＭＷ谷蛋白亚基Ａ－ＰＡＧＥ图谱很容易区分不同品种或基因型。因此，Ａ－ＰＡＧＥ方法麦谷蛋白蛋快速分离与品种鉴定中具有较大的应用潜力     

聚乙烯醇和二羟甲基二羟涂层的作用效果

聚乙烯醇（ＰＶＡ）和二羟甲基二羟（ＤＭＤＨＥＵ）涂层对６５．３５涤粘混纺西服用织物的机械性能具有显著影响。在涂层溶液中增加ＰＶＡ和ＤＭＤＨＥＵ的浓度后，提高了整个织物弯曲刚度，改进了织物折皱回复率。但对降低织物断裂强度及相应的断裂伸长率影响不大，而且据观察不论坯布还是染色布其变化趋势是相同的。     

超临界二氧化碳富集提纯鱼油中EPA和DHA的研究进展（Ⅰ）──超临界二氧化碳与鱼油脂肪酸的相平衡研究

鱼油中的特征脂肪酚ＥＰＡ（廿碳五烯酸）和ＤＨＡ（廿二碳六烯酸）对人体的医疗保健作用受到越来越广泛的重视。综述了近年来人们对超临界二氧化碳（ＳＣ－Ｃ０２）与鱼油脂肪酸相平衡的研究概况，分析了温度、压力、夹带剂等对ＳＣ－ＣＯ２从鱼油脂肪酸混合物中萃取提纯ＥＰＡ和ＤＨＡ的影响。     

有关DHA胶丸（鱼油）质量的几个问题

有关ＤＨＡ胶丸（鱼油）质量的几个问题李力，赵维谦（北京市营养源研究所，北京，１０００５４）（北京市科学技术研究院，北京，１０００）ＤＨＡ与ＥＰＡ是两种多不饱和脂肪酸，化学名称分别是二十二碳六烯酸和二十碳五烯酸。近年来国内外许多学者对其进行了深入的研究...     

超临界二氧化碳富集提纯鱼油中EPA和DHA的研究进展（Ⅱ）

综述了近看来 人们用超临界二氧化碳（ＳＣ－ＣＯ２）从鱼油中富集提纯ＥＰＡ和ＤＨＡ的各类实验装置，讨论了鱼油的预处理方法，萃取操作条件对ＳＣ－ＣＯ２提纯ＥＰＡ和ＤＨＡ的纯度和收率的影响，介绍了一个工业化双塔连续逆流萃取模拟流程。对我国鱼油资源的利用进行了分析。     

EPA和DHA的提取和富集：Ⅰ.原料和化学型式的选择

论述了提取ＥＰＡ和ＤＨＡ的重要意义和原料的选择方法，讨论了富集ＥＰＡ和ＤＨＡ时化学型式的选择原则     

Disappearance of docosahexaenoic and eicosapentaenoic acids from cultures of mixed ruminal microorganisms

Previous studies showed conflicting results regarding the ability of ruminal microorganisms to hydrogenate docosahexaenoic acid (C22:6, DHA) and eicosapentaenoic acid (C20:5, EPA). To determine the disappearance of DHA and EPA from mixed ruminal cultures, 2 ruminal in vitro experiments were conducted using graded levels of DHA and EPA. The first experiment examined DHA added at 0, 5, 10, 15, and 20 mg per culture flask. In the second experiment, EPA was added at 0, 5, 10, and 15 mg per culture flask. Docosahexaenoic acid and EPA were incubated in triplicate in 125-mL flasks, and 5 mL of culture contents was taken at 0, 12, and 24 h for fatty acid analysis by gas liquid chromatography. After 24 h of incubation, 4.1, 4.1, 4.0, and 3.3 mg of DHA disappeared from the 5, 10, 15, and 20 mg of DHA cultures, respectively. In the second experiment, 5, 8.3, and 7.1 mg of EPA disappeared after 24 h of incubation for the 5-, 10-, and 15-mg EPA cultures, respectively. Addition of DHA to cultures increased trans-C18:1 fatty acid accumulation by 105, 91, 82, and 74% for the 5, 10-, 15-, and 20-mg cultures, respectively, compared with control. The addition of EPA increased trans-C18:1 fatty acid accumulation by 56, 64, and 55% for the 5-, 10-, and 15-mg EPA cultures, respectively, compared with control. Addition of DHA and EPA to cultures caused a reduction in C18:1 n-9 and C18:2 n-6 biohydrogenation compared with control. Results from these experiments clearly demonstrate the ability of ruminal microorganism to transform DHA and EPA to other fatty acids causing their disappearance from cultures.     

PUFAs in Fish: Extraction,Fractionation, Importance in Health

ABSTRACT: Polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are currently in demand in the pure form and actively being studied to understand their potential roles in human health. Arachidonic acid, 20:4 (n‐6), and DHA, 22:6 (n‐3), are important in normal neurodevelopment and visual function. Infants fed formula often have low blood lipid 20:4 (n‐6) and 22:6 (n‐3). Consumption of fish oils may increase the 20:5 (n‐3) (EPA) and 22:6 (n‐3) (DHA) in human blood. Some marine fish oils contain higher amounts of arachidonic acid, EPA, and DHA. PUFA contents in different marine fishes and methods for their extraction and fractionation, in terms of fatty acid constituents in the form of methyl esters, are covered in this review. Emphasis is given to the fractionations of EPA and DHA by means of supercritical fluid extractions (SFE). The advantages of SFE compared to conventional methods are discussed in this review. PUFAs are usually extracted at about 10 to 30 MPa and at 40 to 80 °C. SFE is a promising and currently the best technique to extract PUFAs, especially EPA and DHA, from marine and freshwater fish.     

Optimization of omega-3 enriched-diacylglycerol production by enzymatic esterification using a response surface methodology

Incorporation of an eicosapentaenoic acid/docosahexaenoic acid (EPA/DHA) moiety into diacylglycerol (DAG) oil using lipase-catalyzed esterification was optimized using an ethyl ester form of EPA/DHA. A response surface methodology (RSM) was used to optimize reaction parameters (time, temperature, and substrate mole ratio) for incorporation of DHA and EPA into DAG oil. Predictive models for DHA+EPA contents of DAG and the amount of DAG produced after esterification were adequate and reproducible. DHA+EPA contents of DAG significantly increased with reaction time and substrate mole ratio (p<0.05). In contrast, the reaction temperature negatively affected the amount of DAG after esterification. Synthesis of DHA+EPA-enriched DAG was optimized for a maximum DAG content with the highest DHA+EPA content, in which 630.0 mg of DAG containing 34.8% DHA and EPA was predicted using the RSM model. The optimal reaction conditions were predicted at 20.6 h, 57.9 and a DHA/EPAenriched ethyl ester: DAG oil ratio of 2.5:1.     

Restoration of EPA and DHA in rainbow trout (Oncorhynchus mykiss) using a finishing fish oil diet at two different water temperatures

Feeding fish a fish oil finishing diet (FOFD) after grow-out on vegetable oil diet is one strategy to restore eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels. We investigated restoration of EPA and DHA in rainbow trout fed a FOFD preceded by a grow-out period on 50% or 75% palm fatty acid distillate (PFAD) diets at optimal (15 °C) or elevated (20 °C) water temperatures. Using the FOFD restored EPA and DHA in fillet and whole carcass of fish previously fed either 50% PFAD diet from 85% to 98% or 75% PFAD from 66% to 93% of values obtained for fish fed FO diet throughout. Water temperature did not influence EPA and DHA restoration. Growing rainbow trout with diets where FO was replaced by either 50% or 75% PFAD followed by a FOFD reduced FO usage by around 30% and 44% at 15 °C, respectively, and 32% and 48% at 20 °C, respectively.     

Mechanisms of Docosahexaenoic and Eicosapentaenoic Acid Loss from Pacific Saury and Comparison of Their Retention Rates after Various Cooking Methods

The docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents of Pacific saury (Cololabis saira), a fatty fish and staple of the Japanese diet, have been reported to decrease after cooking. This study compared the DHA and EPA contents remaining in saury after grilling, pan‐frying or deep‐frying to center temperatures of 75, 85, or 95 °C, and examined physical loss, lipid oxidation, and thermal degradation as mechanisms of DHA and EPA loss. Temperature changes inside the saury were monitored using thermocouples, while DHA and EPA contents, oxygen radical absorbance capacity, and measurements of lipid oxidation (that is, carbonyl value and thiobarbituric acid value) were determined chemically. Visualization of temperature distribution inside fish samples during cooking revealed large differences in heat transfer among cooking methods. True retention rates in grilled (DHA: 84 ± 15%; EPA: 87 ± 14%) and pan‐fried samples (DHA: 85 ± 16%; EPA: 77 ± 17%) were significantly higher than deep‐fried samples (DHA: 58 ± 17%; EPA: 51 ± 18%), but were not affected by final center temperatures despite differences in cooking times. Physical loss via cooking losses (grilling and pan‐frying) or migration into frying oil (deep‐frying) accounted for large quantities of DHA and EPA loss, while lipid oxidation and thermal degradation did not appear to be major mechanisms of loss. The antioxidant capacity of saury was not significantly affected by cooking treatments. The results of this study suggest that minimization of physical losses during cooking may increase DHA and EPA contents retained in cooked Pacific saury.     

Oregano and rosemary extracts inhibit oxidation of long-chain n-3 fatty acids in menhaden oil

ABSTRACT:  Capabilities of methanol extracts from oregano and rosemary in retarding oxidation of long-chain polyunsaturated fatty acids, docosahexaenoic acid C22:6 (DHA) and eicosapentaenoic acid C20:5 (EPA), in menhaden oil were investigated. The fish oils after mixing with the extracts at different concentrations were oxidized in an accelerated study by heating at 150 °C for 30 min or incubating at 60 °C for 5 d. After heating at 150 °C, only 15.9% of DHA and 18.5% of EPA remained in the fish oil without extract, while 38.8% to 65.9% of DHA and 44.7% to 69.0% of EPA were retained in the fish oil mixed with 1% to 5% of oregano extract. The highest retained DHA (56.9%) and EPA (58.0%) in the fish oils mixed with rosemary extract were observed at 2.5% addition. Increasing rosemary extract to 5% lowered its capability of inhibiting DHA and EPA oxidation. After incubation at 60 °C for 5 d, the highest inhibition capability was also found at 2.5% of added rosemary extract, and the oil retained 88.2% DHA and 88.3% EPA. However, only 18.8% DHA and 23.6% EPA were retained in the fish oil mixed with 5% of oregano extract and no DHA and EPA were detected in the fish oil without extract after 5-d incubation at 60 °C. Thus, antioxidant activity of the rosemary extract was greater than that of oregano extract, but was sensitive to heat. The rosemary extract also demonstrated higher DPPH (2,2'-diphenyl-1-picrylhydrazyl) free radical scavenging capability, which was approximately 3 times higher than oregano extract, although there was no significant difference in the total phenolic contents between both extracts.     

超临界CO_2流体萃取大马哈鱼籽中DHA和EPA的工艺

以DHA和EPA的提取率、鱼籽油中DHA和EPA的含量为测定指标,分别研究了收集压力、萃取压力、萃取温度、萃取时间和夹带剂用量比例对超临界CO2流体萃取冻干鱼籽粉中DHA和EPA的影响。结果表明:超临界CO2流体萃取冻干鱼籽粉中DHA、EPA最佳条件为:萃取压力20MPa,萃取温度55℃,夹带剂比例1∶4,萃取时间2h,收集压力30MPa,收集温度65℃。在此条件下,DHA的提取率可达55.81%,EPA的提取率可达56.93%,萃取出的鱼籽油中DHA的含量达到161.26mg/g,EPA的含量可达170.03mg/g。     

POSITIONAL DISTRIBUTION OF FATTY ACIDS IN TRIACYLGLYCEROLS OF SEAL BLUBBER OIL

The positional distribution of long-chain ω3 polyunsaturated fatty acids namely eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) in the triacylglycerol (TAG) molecules of seal blubber oil was determined and compared with that of commercially available menhaden oil via stereospecific analysis. In seal blubber oil, EPA, DPA and DHA occurred mainly in the sn-1 and sn-3 positions of the TAG molecules. The amounts were EPA, 8.36 and 11.2; DPA, 3.99 and 8.21; and DHA, 10.5 and 17.9%, respectively. In menhaden oil, DPA and DHA occurred mainly in the sn-2 position of the TAG at 3.11 and 17.2%, respectively. However, EPA was equally distributed in the sn-2 and sn-3 positions and was present only in minute amounts in the sn-1 position.     

Preliminary results on the relative incorporation of docosahexaenoic and eicosapentaenoic acids into cows milk from two types of rumen protected fish oil

Effects of feeding two different types of rumen protected fish oil for 5 days (approximately 1.1 kg of oil per day, containing docosahexaenoic (DHA, C_22:6) and eicosapentaenoic (EPA, C_20:5) in the ratios of 4.8:1 or 0.6:1; DHA:EPA) on the fatty acid composition of milk from Friesian cows in mid-lactation grazing pasture was examined.Feeding the DHA enriched supplement increased the proportion of DHA and EPA in milk to 2.19% and 1.25%, respectively. There was a major difference in the apparent transfer of DHA and EPA from the diet into milk (7.8% and 21.1%, respectively). In comparison, feeding the EPA enriched supplement the proportions of DHA and EPA increased to 0.69% and 1.36%, respectively. The apparent transfer of DHA and EPA from the protected lipid supplement was similar, being 6.8% and 8.1%, respectively. Both types of fish oil increased the proportion and yield of C_18:1 trans and C₁₈ conjugated linoleic acid (CLA) in milk fat. The C_18:1 trans was greater in milk fat from the high EPA supplement (13.7% and 17%, DHA and EPA enriched supplement, respectively) and likewise the proportion of c-9, t-11 CLA was greater (2.9% and 5.1%; DHA and EPA enriched supplement, respectively); this may be due to the lower ruminal protection of the high EPA supplement.     

Omega-3 fatty acids affected human perception of ground beef negatively

The objective was to determine the impact of increasing levels of Eicosapentaenoic acid (EPA; C20:5n3) and Docosahexaenoic acid (DHA; C22:6n3) on beef palatability. Two commercial supplements of EPA and DHA were added to 85% lean ground beef patties (176.2 ± 3.76 g) with different levels (0, 0.3, 0.4, 0.5, 0.6, 0.7, and 1% as-is). Olive oil was added so that all patties contained 1% added lipid. A control treatment was also prepared with no supplement or olive oil. Sensory evaluation and fatty acid analysis was conducted. Ground beef flavor decreased linearly (P<0.001) with increasing levels of EPA and DHA. Off-aroma and off-flavor increased linearly and then plateaued with increasing levels of EPA (P<0.0001). In conclusion, EPA had a greater negative impact on beef palatability than DHA. Also, the panelists were more sensitive to EPA in off-flavor perception than off-aroma.