共查询到20条相似文献,搜索用时 15 毫秒
1.
Squid visceral oil contains high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Its ethyl esters were
fractionated by short-path distillation in this study. The elimination temperatures of squid visceral oil ethyl esters (SVOEE)
ranged from 50 to 140°C, increasing with the carbon number of ethyl esters. The elimination temperature of cholesterol was
higher than those of SVOEE. The SVOEE of Illex argentinus (SVOEE-A) was more advantageous as the raw material (feed) than that of Ommastrephes bartrami (SVOEE-B) for the isolation of EPA and DHA, because SVOEE-A contained less 20∶1 and 22∶1. When SVOEE-A originally containing
9.0% EPA, 14.7% DHA, and 1,121 mg/100 g of cholesterol was distilled from 50 to 150°C with 20°C interval, the 130°C distillate
could give 15.5% EPA and 34.7% DHA with 99 mg/100 g of cholesterol, and the yield was 21.8%. The 150°C distillate could give
43.1% DHA with 496 mg/100 g of cholesterol. Furthermore, the distillates collected from 110 to 150°C contained 24.4 to 50.2%
of EPA plus DHA, and their total yield was 58.3%. The final residue after 150°C distillation contained 77% of the total cholesterol
in the initial SVOEE-A, and the yield was 6.0%. 相似文献
2.
Ting Xu Qingru Zeng Xin Liu Shensheng Xiao Xiaoming Jiang Yuepeng Lu Zhiyong Gong Yonggui Gao Min Fang 《Journal of the American Oil Chemists' Society》2023,100(8):615-621
There are more and more studies on the detection method of 3-chloro-1,2-propanediol fatty acid esters (3-MCPD esters) at present, by comparing these methods for the determination of 3-MCPD esters. Indirect methods, which determine total amount of 3-MCPD after hydrolysis of the esters, have an advantage over direct methods. The existing indirect methods, however, may yield unreliable results or require long hours of alkaline methanolysis. In contrast, the indirect enzymatic hydrolysis method has mild conditions and more accurate results. In this study, we developed a reliable and rapid indirect method for determination of 3-MCPD esters. 3-MCPD esters were enzymolysis to 3-MCPD by indirect enzymatic hydrolysis method, and the conditions of enzymatic hydrolysis were optimized, the content of 3-MCPD after enzymatic hydrolysis was detected by gas chromatography–mass spectrometry (GC–MS) and the yield was calculated. Finally, the optimum conditions for enzymatic hydrolysis of 3-MCPD esters were determined. According to the optimal enzymatic hydrolysis condition, the contents of 3-MCPD esters in four food oils were determined. The method is simple and sensitive and can meet the requirement of 3-MCPD esters detection in general oils. 相似文献
3.
Hao Lu Shangde Sun Yanlan Bi Guolong Yang Rulan Ma Huifang Yang 《European Journal of Lipid Science and Technology》2010,112(10):1101-1105
Epoxides of soybean oil methyl esters (SMEs) are biodegradable, non‐toxic, and renewable epoxy plasticizers. The objective of the present work was to investigate the effects of free fatty acids on the enzymatic epoxidation of SMEs. The results showed that the epoxidation of SMEs depended on the type of the added free fatty acid. For saturated (≤C18:0) and monounsaturated free fatty acids, the epoxy oxygen group content (EOC) of SMEs increased with increasing carbon chain length of free fatty acids; for branched‐chain unsaturated free fatty acids, the EOC of SMEs decreased in the presence of hydroxyl group (OH) and hydroperoxide (OOH) of free fatty acids; the EOC of SMEs decreased with increasing number of double bonds of free fatty acids. The maximum EOC and the initial epoxidization rate (V0) linearly decreased with increasing peroxide value of SMEs. The highest EOC (6.87 ± 0.3%) of SMEs was obtained using behenic acid as reaction material, which was similar with that of stearic acid (EOC 6.75 ± 0.2%). 相似文献
4.
The aim of this paper was to develop a process for the production of DAG from butterfat through glycerolysis and short-path
distillation and to evaluate the physical properties of the DAG in comparison with the original butterfat. Chemical glycerolysis
produced a mixture of acylglycerols containing DAG together with MAG and TAG. From the mixture of glycerolysis products, MAG
were removed through three consecutive distillations (vacuum <0.001 mbar) at 150°C. TAG were separated from DAG by distillation
at 210°C, which gave a product with more than 80% DAG in the distillates. Distillation temperatures had significant effects
on acyl migration. The formation of desirable 1,3-DAG was favored at higher temperatures. Under 210°C distillation, the equilibrium
ratio of 6∶4 was obtained between 1,3-DAG and 1,2(2,3)-DAG. The FA profile of the DAG product was relatively similar to the
original butterfat. The total DAG recovery was around 77% in the pilot-scale production. The different patterns of m.p. were
observed between butterfat and the DAG fraction produced as well as the MAG fraction collected. Solid fat content profiles
of the DAG fraction and its mixtures with rapeseed oil possessed trends similar to those of the corresponding butterfat and
its mixtures with rapeseed oil. Compared with butterfat, the DAG fraction behaved differently in its thermal profiles, crystallization
patterns, and rheological properties; for example, the dropping point was 13°C higher for the latter than for the former,
and the crystal pattern was mostly β form for the latter, whereas the former was the β′ form. 相似文献
5.
Contamination of Fried Foods by 3-Monochloropropane-1,2-diol Fatty Acid Esters During Frying
下载免费PDF全文
![点击此处可从《Journal of the American Oil Chemists](/ch/ext_images/free.gif)
In the present work, different foods including banana, potato, cassava, onion, garlic, polenta, rice balls and beef patties were investigated in relation to the possible endogenous formation of 3-monochloropropane-1,2-diol fatty acid esters (bound 3-MCPD) and carry-over of these contaminants from the oil due to fat uptake during frying. For that, the samples were fried in two different types of oil and bound 3-MCPD was determined by using an indirect method based on acid transesterification and gas chromatography coupled to mass spectrometry analysis. The compounds were not detected in the fried foods when corn oil containing non-significant levels of bound 3-MCPD (<0.05 mg kg?1) was used, indicating no endogenous formation during frying. On the other hand, when the same foods were fried in palm oil containing 1.64 mg kg?1 of bound 3-MCPD, the mean concentrations ranged from 0.12 to 0.25 mg kg?1, indicating a clear carry-over of the contaminants. In this case, a good correlation was observed between the levels of the compounds in fried samples and water loss/fat uptake. 相似文献
6.
Fernando Israel Gómez-CastroVicente Rico-Ramírez Juan Gabriel Segovia-HernándezSalvador Hernández-Castro 《Chemical Engineering Research and Design》2011,89(4):480-490
Biodiesel fuel has been shown as a clean energy alternative to petroleum diesel. Conventional biodiesel production involves the use of catalyst, which implies high energy consumptions for the separation of both the catalyst and the by-products of the reaction, including those of the undesirable reaction of saponification. Recently, a process involving the use of short-chain alcohols at supercritical conditions has been proposed (Saka-Dadan process); one of the main advantages of that process is that it avoids the need for a catalyst as well as the occurrence of the saponification reaction. However, although the process requires less pieces of equipment than the conventional one, its energy requirements are still high, making biodiesel fuel more expensive than petroleum diesel. This work proposes the use of reactive distillation and thermally coupled reactive distillation configurations to produce biodiesel fuel by the supercritical methanol method. First-order kinetics is used to represent the esterification reaction, obtaining high conversions in a single shell. Both of the configurations proposed reduce energy requirements when compared to the conventional (Saka-Dadan) process. Calculations were also performed to estimate CO2 emissions, thermodynamic efficiency and cost. The thermally coupled reactive distillation configuration shows to be the best alternative in terms of energy consumption, CO2 emissions and thermodynamic efficiency. Further, cost estimations also show that the use of a thermally coupled scheme considerably reduces both utilities and capital costs. 相似文献
7.
A new short-path distillation system applied to the reduction of cholesterol in butter and lard 总被引:5,自引:0,他引:5
Armando Lanzani Paolo Bondioli Carlo Mariani Liliana Folegatti Stefania Venturini Enzo Fedeli Pierre Barreteau 《Journal of the American Oil Chemists' Society》1994,71(6):609-614
A molecular distillation plant, built particularly to increase the separation efficiency and to obtain safer working conditions,
was tested to remove cholesterol from anhydrous butter and lard. A preliminary experiment was carried out with butter to evaluate
the fractionation obtained at temperatures between 190 and 250°C and residual pressures between 10−3 and 10−4 torr. A second experiment was carried out at 185°C and at the maximum operational vacuum, evaluating the fractionation achieved
within a time scale between 30 and 180 min. Cholesterol was almost completely removed during the second hour with minimal
loss of low-molecular weight triglycerides. An experiment was carried out with lard at 250°C and maximum achievable operational
vacuum (10−4 Torr), lasting approximately 6 h, and cholesterol was removed almost completely during the second hour without significant
modifications in the triglyceride composition. This situation remained constant throughout the duration of the test. 相似文献
8.
汽车尾气严重污染环境,为了生产满足环保法规的硫含量低于10μg/g的汽油,提出了在传统的萃取蒸馏中以有机溶剂+离子液体(IL)为复合萃取剂的脱硫法。以与真实催化裂化(FCC)汽油组成及物性相近的模型油为模拟汽油,利用COSMO-RS模型计算了30种常见IL对环己烷-噻吩的选择性和溶解能力,筛选出用于萃取蒸馏脱硫添加剂的最佳离子液体为[EMIM][BF4]。通过Aspen Plus软件以N-甲酰吗啉(NFM)+[EMIM][BF4]为复合萃取剂进行了汽油脱硫的工艺流程模拟与优化。优化结果为萃取剂由NFM(质量分数98%)和[EMIM][BF4](质量分数2%)构成,萃取蒸馏塔质量回流比R=0.4,剂油质量比S/F=1,采出率为70%。模拟结果表明:萃取蒸馏可高效地脱除苯并噻吩、硫醚及噻吩类硫化物,上述硫化物总量可从1581μg/g降低至5.37μg/g,脱硫率达98.1%,质量收率为70%,体积收率为75%。此外,通过对比计算值与文献中实验值,验证了COSMO-RS预测IL热力学性质、UNIFAC预测有机硫化物-烃类汽液相平衡的准确性和模拟工艺流程的可靠性。 相似文献
9.
Determination of free fatty acids in palm oil by near-infrared reflectance spectroscopy 总被引:9,自引:4,他引:5
A near-infrared (NIR) spectroscopy calibration was developed for the determination of free fatty acids (FFA) in crude palm
oil and its fractions based on the NIR reflectance approach. A range of FFA concentrations was prepared by hydrolyzing oil
with 0.15% (w/w) lipase in an incubator at 60°C (200 rpm). Sample preparation was performed in Dutch cup, and the spectra
were measured in duplicate for each sample. The optimized calibration models were constructed with multiple linear regression
analysis based on C=O overtone regions from 1850–2050 nm. The best wavelength combinations were 1882, 2010, and 2040 nm. Multiple
correlation coefficients squared (R
2) were: 0.994 for crude palm oil, 0.961 for refined-bleached-deodorized (RBD) palm olein, and 0.971 for RBD palm oil. Calibrations
were validated with an independent set of 8–10 samples. R
2 of validation were 0.997, 0.943, and 0.945, respectively. The developed method was rapid, with a total analysis time of 5
min, and environmentally friendly, and its accuracy was generally good for raw-material quality control. 相似文献
10.
1,2-butanediol (1,2-BDO) and 1,2-propanediol (1,2-PDO) are inevitably side produced in the ethylene glycol (EG) production processes from non-petroleum routes, but are very difficult to separate by the ordinary distillation method because of the closeness of their boiling temperatures to EG, thus compromise the economy of these processes. The azeotropic distillation process using 1-octanol (CPO) as an entrainer to separate EG and 1,2-BDO mixture with or without 1,2-PDO was studied in this paper. Four binary vapour–liquid equilibrium data of EG-1,2-BDO, EG-CPO, 1,2-BDO-CPO, and 1,2-PDO-CPO were measured using an Ellis equilibrium kettle and regressed with the thermodynamic model of non-random two liquid to obtain the corresponding binary interaction parameters. On this basis, azeotropic distillations with CPO as an entrainer were designed to separate EG and 1,2-BDO with or without 1,2-PDO. The complete separation processes, including the azeotropic distillation and CPO recovery process consisting of extraction with H2O and subsequent distillation, were simulated and optimized with Aspen Plus for both the EG-1,2-BDO binary mixture and the EG-1,2-BDO-1,2-PDO ternary mixture. The simulation results show that the azeotropic distillation method with CPO as an entrainer can effectively separate the mixture of EG-1,2-BDO and EG-1,2-BDO-1,2-PDO, achieving EG of 99.90% purity with 99.98% recovery and 1,2-BDO of 99.30% purity with 99.45% recovery for the binary mixture, and achieving EG of 99.90% purity with 99.80% recovery, 1,2-BDO of 99.35% purity with 99.35% recovery, and 1,2-PDO of 90.59% purity with 94.38% recovery for the ternary mixture. These processes are promising for industrial application and can significantly improve the economy of non-petroleum EG production. 相似文献
11.
12.
D. K. Feeter 《Journal of the American Oil Chemists' Society》1974,51(4):184-187
A twofold technique for determination of tocopherols and a gas liquid chromatography procedure for determination of sterols
and steryl esters are described. Incorporated herein are a modified Emmerie-Engel procedure for total tocopherols and gas
liquid chromatographic analysis for tocopherols and sterols as their propionate esters. The approach is directly applicable
to quality control and production use. 相似文献
13.
Richard J. Phillips Bert Singleton 《Journal of the American Oil Chemists' Society》1978,55(2):225-227
Peanut oil is dissolved in 2,2,4-trimethylpentane standard. The free acids are extracted into N,N-dimethylformamide as their
sodium salts and treated with methyl iodide. The resulting methyl esters are analyzed by gas chromatography. A typical result
for oleic acid is about 200 ppm with a relative standard deviation of 6%. An average recovery of 95% is obtained from a sample
spiked with an additional 200 ppm of oleic acid. Evidence is presented that the procedure does not give high values as a result
of sample hydrolysis. 相似文献
14.
按气、液两相在多孔介质中不同的流动与接触方式,将应用于蒸馏过程强化的多孔介质传质元件分为三大类进行了系统的介绍,即气/液两相均在多孔介质内部流动的气液逆流接触方式、气相在多孔介质内部流动/液相在多孔介质表面流动的气液错流接触方式以及液相在多孔介质内部流动/气相在多孔介质表面流动的气液逆流接触方式。详细阐述了本课题组对各类多孔介质传质元件的研究思路与历程,总结其流体力学和传质性能与相应传统传质元件相比的优缺点,进而指出了多孔介质泡沫材料强化传质过程的作用机理是其能在蒸馏过程中得以多元化应用所亟待解决的关键科学问题。 相似文献
15.
使用湿式减压蒸馏法分离轧钢含油污泥的油分和残渣。采用二次通用旋转组合设计实验,研究了温度、真空度和水蒸气流量对分离效果的影响。结果表明,相比于简单蒸馏,湿式减压蒸馏能显著减轻对油分的破坏,提高油分回收率。在实验参数范围内,当蒸馏温度为321.4℃、真空度为90 kPa、水蒸气流量为1 ml·min−1时,获得最大油分回收率(57.2%)。回收油分时,过高的温度和水蒸气分压会破坏油分,前者促进油分胶质组分向芳香烃和饱和烃转化,后者则会促进脂类水解,并与Fe2O3作用氧化重质油组分,促进胶质组分向芳香烃转化。而对于蒸馏残渣中难以分离的沥青质等大分子有机物,可通过提高温度和水蒸气流量,特别是可以提高温度,促使其分解炭化,以获得较低的残渣含油率,便于残渣中铁金属元素的回收利用。 相似文献
16.
This study was designed to test the hypotheses that digestibility and post-absorption metabolism of fish oil are influenced
by impaired lipolysis and by the stereospecific composition of its triacylglycerols. Male Wistar rats were fed nonpurified
diets containing one of the following fat sources: 9% native fish oil (NFO), 9% autorandomized fish oil (RFO), 8.1% fish oil-derived
free fatty acids (FO-FFA) plus 0.9% glycerol, or 9% soybean oil (SO) as a reference fat. In a 24-day balance study, apparent
digestibility of total dietary fat averaged 93.1% in the SO, NFO and RFO groups, and 90.9% in the FO-FFA group. Randomization
of fish oil had no effect on apparent digestibility of individual fatty acids. In rats fed FO-FFA, apparent absorption of
saturated and monounsaturated fatty acids was lower when compared to the NFO and RFO groups. Feeding the FO-FFA diet tended
to increase plasma triglyceride content. The hypocholesterolemic effect of polyunsaturated n−3 fatty acids was not influenced
by the dietary source. Similar effects on fatty acid profiles of plasma and liver phospholipids were caused by the NFO, RFO
and the FO-FFA diets. We conclude that once polyunsaturated n−3 fatty acids are absorbed, their effect on lipid metabolism
is not determined by the dietary source. 相似文献
17.
Karna Narayana Prasanna Rani Thella Prathap Kumar Tulasi Sri Venkata Ramana Neeharika Bankupalli Satyavathi Rachapudi Badari Narayana Prasad 《European Journal of Lipid Science and Technology》2013,115(6):691-697
Kinetic studies have been carried out on the esterification of free fatty acids (FFAs) in jatropha oil with methanol in the presence of sulphuric acid catalyst at 5 and 10 wt% concentrations relative to free fatty acids (0.4–0.8 wt% relative to oil) and methanol–FFA mole ratios ranging from 20:1 to 80:1. It has been found that a 60:1 methanol–FFA mole ratio and 5 wt% catalyst at 60°C and 500 rpm or above provided a final acid value lower than 1 mg KOH/g oil within 60 min. A kinetic model has been proposed with second‐order kinetics for both the forward and backward reactions. The effect of temperature on the reaction rate constants and equilibrium constant has been determined using Arrhenius and von't Hoff equations, respectively. The heat of reaction was found to be ?11.102 kJ/mol. 相似文献
18.
This paper discusses a rapid GC-FID technique for the simultaneous quantitative analysis of FFA, MAG, DAG, TAG, sterols, and
squalene in vegetable oils, with special reference to palm oil. The FFA content determined had a lower SE compared with a
conventional titrimetric method. Squalene and individual sterols, consisting of β-sitosterol, stigmasterol, campesterol, and
cholesterol, were accurately quantified without any losses. This was achieved through elimination of tedious conventional
sample pretreatments, such as saponification and preparative TLC. With this technique, the separation of individual MAG, consisting
of 16∶0, 18∶0, and 18∶1 FA, and the DAG species, consisting of the 1,2(2,3)- and 1,3-positions, was sufficient to enable their
quantification. This technique enabled the TAG to be determined according to their carbon numbers in the range of C44 to C56. Comparisons were made with conventional methods, and the results were in good agreement with those reported in the literature. 相似文献
19.
N. E. Hetman H. G. Arlt Jr. M. Neglia 《Journal of the American Oil Chemists' Society》1969,46(10):569-569
2,2″-Methylenebis (trans-3,5-dimethoxystilbene) has been isolated from tall oil fatty acid after reaction with paraformaldehyde in the presence of
an acid catalyst. 相似文献
20.
Enzymatic ethanolysis of fish oil for selective concentration of polyunsaturated fatty acids (PUFAs) with flexible production of corresponding glycerides and ethyl esters
下载免费PDF全文
![点击此处可从《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Xin Yan Xuebing Zhao Gaojian Ma Lingmei Dai Wei Du Dehua Liu 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2018,93(8):2399-2405