Enrichment of Omega-3 Fatty Acids of Refined Hoki Oil

Enrichment of the omega-3 (n-3) fatty acids of refined hoki oil (RHO) intact triglycerides (TG) and via free fatty acids (FFA), was carried out in the present study using established methods of dry fractionation (DF), low temperature solvent crystallization (LTSC) and urea complexation (UC) and positional distribution of fatty acids in the intact TG was determined by Nuclear Magnetic Resonance (NMR) analysis. Results showed that n-3 fatty acids were enriched in liquid fractions of all methods except DF, where the highest concentration was obtained via the UC method (83.00 %). The FFA form of the oil produced a higher concentration (40.81 %) of n-3 fatty acids via the LTSC method compared to the TG form (31.50 %). The percentages of the total saturated fatty acid (SFA) in the liquid fractions in all methods were lower, ranging from 1.60 % (UC) to 21.44 % (DF) compared to the RHO parent oil (24.05 %). The percentages of total monounsaturated fatty acids (MUFA) in the liquid fractions were similar to the solid fractions except for the UC method where total MUFA was six times higher in the solid fraction. In LTSC-FFA and UC methods, the enrichment factor for EPA was lower, ranging from 1.61 (LTSC-FFA) to 2.83 (UC), than DHA which ranged from 1.64 (LTSC-FFA) to 3.88 (UC). EPA was preferentially located at the sn-1,3 position and DHA was significantly located at the sn-2 position which is the favoured location for intestinal digestion.     

大豆油脱臭馏出物中角鲨烯的富集研究

以大豆油脱臭馏出物(SODD)为原料,研究了经皂化和二级分子蒸馏过程提取角鲨烯的工艺路线。分别采用正交试验设计和响应面法对皂化及第一级分子蒸馏工艺条件进行优化,所得优化条件为:皂化反应时间40 min,反应温度80℃,KOH浓度0.8 mol/L;一级分子蒸馏过程蒸发温度73℃,进料速率1.1 mL/min,刮膜转速250 r/min。经过二级分子蒸馏,角鲨烯质量分数从原料中的1.95%富集到21.01%,总收率为86.8%。     

Enrichment of Omega-3 Polyunsaturated Fatty Acid Methyl Esters by Ionic Liquids Containing Silver Salts

Abstract

In this paper, we demonstrate that the hydrophobic ionic liquid (IL) such as 1-hexyl-3-methyl imidazolium hexafluorophosphate, [hmim][PF₆], with silver salt, e.g. AgBF₄, is an excellent extraction phase to separate and enrich omega-3 polyunsaturated fatty acid methyl esters (PUFAMEs) from the mixed solution containing closely related saturated, monounsaturated or diunsaturated fatty acid methyl esters. With this silver salt-ionic liquids extraction phase, the health-beneficial omega-3 PUFAMEs such as methyl ester of all-cis-5,8,11,14,17-eicosapentaenoic acid (20:5 or EPA) and methyl ester of all-cis-4,7,10,13,16,19-docosahexaenoic acid (22:6 or DHA) were largely enriched from 18% (wt %) in the original cod liver oil to greater than 80% in the 1-hexene stripping solvent. The unique properties of nonvolatility and adequate polarity allow ILs to dissolve or suspend silver salts and to be conveniently adopted as extraction phase in separating PUFAMEs. The ILs with different hydrophobicities and different silver salts were screened to obtain an optimal combination of IL and silver salt with the highest extraction capability and selectivity. The screening results showed that AgBF₄ exhibited high extraction capability in the hydrophobic ILs but little or no extraction capability in the hydrophilic ILs. Furthermore, the high extraction capability of AgBF₄ in hydrophobic ILs was much greater than that of AgBF₄ in traditional silver-water or silver-alcohol extraction systems. Pretreating the silver-ILs extraction phase with steric hindered short chain olefins could significantly enhance its extraction selectivity for PUFAMEs. Nine runs of the IL-silver extraction phase showed no obvious decrease in its extraction capabilities and selectivities.     

稀油密封型干式储气罐密封油的破乳

稀油密封型干式储气罐的密封油,在循环使用中会出现乳化变质,通过对乳化机理和原料的分析,提出了破乳方法和破乳剂的选择方案。     

迷宫式油封的研制

介绍迷宫式油封的胶料配方设计和试制,在耐油老化和装车运行考验中,其密封性好、耐老化、寿命长的特点,使橡胶迷宫式货车轴承密封装置的优越性得到较好地体现。     

油浆蒸汽发生器的密封改造

充分利用原设计结构的特点及波齿复合垫的优异密封性能 ,对油浆蒸汽发生器的密封进行了改造 ,避免了难度较高的机械加工 ,取得了满意的效果     

尿素包合法富集鱼油中的EPA和DHA的工艺研究

运用尿素包合法富集鱼油中的EPA和DHA。考察了尿脂比、反应温度、结晶温度和结晶时间对EPA和DHA总纯度的影响。随尿脂比的增大,总纯度先增大后趋于稳定,适宜的尿脂比为2．5：1。随反应温度的升高,总纯度逐渐增大,适宜的反应温度为55℃。随结晶温度的降低,总纯度逐渐增大,适宜的结晶温度为0℃。随结晶时间的增大,总纯度先增大后趋于稳定,适宜的结晶时间为1h。     

Antioxidant Efficacy of a New Synergistic,Multicomponent Formulation for Fish Oil Omega-3 Concentrates

Today, tocopherols serve as the industrial standard antioxidant protection for fish oil omega-3 concentrates. Synergistic interactions between tocopherols, ascorbyl palmitate and natural polyphenols extracted from plant sources have been demonstrated in model systems. The main goal for this work was to develop a mix of such antioxidants with improved efficacy in the context of preserving industrial marine oil concentrates. The antioxidant formulation comprises tocopherols, ascorbyl palmitate, rosemary extract and green tea catechins. Part of the scope was to develop a method for dissolving green tea catechins in oil. The key element of the method is to introduce green tea on a lipid insoluble carrier when dissolving the extract in the oil, and thereafter remove the carrier by filtration. The antioxidant mix was tested against tocopherol in omega-3 concentrates of minimum 300 mg/g eicosapentaenoic acid (EPA) plus 200 mg/g docosahexaenoic acid (DHA) in the form of triacylglycerides and ethyl esters. The mix was superior compared to tocopherols in suppressing both primary- and secondary oxidation. Weight increase measurements of oil in contact with air correlated well with standard oxidation tests within individual samples and the method was considered simple and useful for monitoring oxidation in omega-3 concentrates.     

蜡油催化轴流风机油封改造

炼油厂一车间蜡催装置公司级设备402主风机组,风机后油封存在漏油现象,如不彻底清除该隐患,润滑油漏量大时与烟气接触很容易造成火灾事故,也会给机组的平稳运行带来重大的生产隐患。     

Plasma Omega-3 Fatty Acid Response to a Fish Oil Supplement in the Healthy Elderly

Little information is available concerning whether incorporation of dietary omega-3 fatty acids into plasma lipids changes during healthy aging. Elderly (74 ± 4 years old) and young (24 ± 2 years old) adults were given a fish oil supplement for 3 weeks that provided 680 mg/day of docosahexaenoic acid and 320 mg/day of eicosapentaenoic acid, followed by a 2 week wash-out period. Compliance was monitored by spiking the capsules with carbon-13 glucose, the excretion of which was measured in breath CO₂. In response to the supplement, plasma docosahexaenoic acid rose 42% more in the elderly but eicosapentaenoic responded similarly in both groups. Despite raising docosahexaenoic acid intake by five to tenfold, the supplement did not raise plasma free docosahexaenoic acid (% or mg/dL) in either group. We conclude that healthy aging is accompanied by subtle but significant changes in DHA incorporation into plasma lipids.     

Stearidonic Acid-Enriched Soybean Oil Increased the Omega-3 Index, an Emerging Cardiovascular Risk Marker

A plant source of omega-3 fatty acid (FA) that can raise tissue eicosapentaenoic acid (EPA) and/or docosahexaenoic acid (DHA) is needed. A soybean oil (SBO) containing approximately 20% stearidonic acid [SDA; the delta-6 desaturase product of alpha-linolenic acid (ALA)] derived from genetically modified soybeans is under development. This study compared the effects of EPA to SDA-SBO on erythrocyte EPA+DHA levels (the omega-3 index). Overweight healthy volunteers (n=45) were randomized to SDA-SBO (24 ml/day providing approximately 3.7 g SDA) or to regular SBO (control group) without or with EPA ethyl esters (approximately 1 g/day) for 16 weeks. Serum lipids, blood pressure, heart rate, platelet function and safety laboratory tests were measured along with the omega-3 index. A per-protocol analysis was conducted on 33 subjects (11 per group). Compared to baseline, average omega-3 index levels increased 19.5% in the SDA group and 25.4% in the EPA group (p<0.05 for both, vs. control). DHA did not change in any group. Relative to EPA, SDA increased RBC EPA with about 17% efficiency. No other clinical endpoints were affected by SDA or EPA treatment (vs. control). In conclusion, SDA-enriched SBO significantly raised the omega-3 index. Since EPA supplementation has been shown to raise the omega-3 index and to lower risk for cardiac events, SDA-SBO may be a viable plant-based alternative for providing meaningful intakes of cardioprotective omega-3 FAs.     

PLC控制油封供油装置的研制

研制了一种有PLC控制的自动化油封供油装置,使油封过程中的加温、脱水和加注一次性完成,并且实现了温度、压力和流量自动控制,保证了油封质量、提高了油封工作效率.     

ZLH型减速机油封的改进

减速机漏油现象普遍存在,文章介绍了对减速机轴封盖进行双重密封形式的改进方法及效果。     

汽车油封的研究与进展

基于油封"新月面理论"和微型泵理论的密封机理,从油封结构和油封用橡胶材料两方面论述了油封的密封性能与两者的关系。展望了油封技术的发展趋势。     

Modulation of the Selectivity of Immobilized Lipases by Chemical and Physical Modifications: Release of Omega-3 Fatty Acids from Fish Oil

Three different lipases (from Candida antarctica fraction B (CALB), Thermomyces lanuginose (TLL), and Rhizomucor miehei (RML)) were immobilized by two different methods, immobilization on CNBr-activated Sepharose via a mild covalent immobilization or adsorption onto hydrophobic supports (Octyl-Sepharose). These immobilized preparations were chemically and physically modified on the protein surface (enzyme carboxylic groups with ethylenediamine, amino groups with succinic anhydride, or coating with polyethyleneimine).The activity and selectivity in the production of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) by enzymatic hydrolysis of sardine oil were evaluated. Activity and selectivity were dependent on the different lipases, the immobilization protocols, the modification methods, and the pH of the reaction media. The selectivity (EPA/DHA ratio) of RML immobilized on CNBr-activated Sepharose was increased after succinylation from 7.5 to 34 at pH 6.0. The selectivity of octyl-RML improved from 1.5 to 8.5 when pH was increased from 6 to 8. The selectivity and activity of octyl-TLL increased twofold after PEI coating at pH 6. The properties of CAL-B derivatives were slightly altered after modification.     

Preparation of Omega-3 PUFA Concentrates from Fish Oils via Urea Complexation

The effect of weight ratio of urea to fatty acids and the urea-fatty acid adduct crystallization temperature on the enrichment of eicosapentaenoic acid from marine oil fatty acids was studied. The optimum ratio of urea to fatty acids was found to be 3 : 1 for laboratory scale preparations and the optimum temperature for the formation of urea-fatty acid adduct was 1°C. At very low temperatures (?12, ?18, ?35°C) the recovery efficiency for EPA was reduced. Using these optimum values, enrichment of EPA and other n-3 polyunsaturated fatty acids via urea complexation was carried out on a pilot plant scale in a variety of North Atlantic and North Pacific fist oils and a seal oil. Irrespective of hte type of starting oil, all the oils gave a concentrate with 69–85% total n-3 PUFA with an overall yield of 17–20%. Menhaden is clearly an ideal oil for preparation of EPA concentrate, as the starting oil usually has a higher proportion of EPA to DHA than most of the other commercial fish oils.     

浅谈汽车发动机油封的现状与发展

对我国汽车发动机油封生产的现状,从原材料、工艺、设备等方面进行了简单分析,指出国内外的差距,并对今后的发展提出几点粗浅的建议。     

汽车油封橡胶材料的研究进展

橡胶密封制品是汽车用橡胶制品不可缺少的重要组成部分,对汽车行驶的舒适性、安全性起到重要的作用。介绍了几种主要的汽车油封橡胶材料与性能以及研究进展,包括丁腈橡胶(NBR)、丙烯酸酯橡胶(ACM)、氟橡胶(FKM)、氢化丁腈橡胶(HNBR)、氟硅橡胶(MFQ)和聚四氟乙烯(PTFE)。     

压缩机油封失效分析与对策

机械油封的工作条件与环境是复杂多变的,因而它的失效形式也是诸多因素交互影响所致,文章介绍了油封的结构及密封原理,分析了氢气压缩机油封的失效原因,并针对氢气压缩机油封失效提出了解决措施,在装置检修期间对新氢机油封进行了更换,解决了氢气压缩机油封泄漏问题。