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1.
T. Perlstein A. Eisner I. Schmeltz 《Journal of the American Oil Chemists' Society》1974,51(8):335-339
In efforts to prepare wax esters chemically similar to those comprising sperm oil, selected fats or blends thereof were reduced
to alcohols which then were reacted with the initial triglycerides to get such wax esters. For instance, lard oil was reduced
to lard oil alcohol in the presence of sodium and methyl isobutyl carbinol in xylene. Most of the resulting sodium alcoholates
(95–98%) were decomposed with urea, and subsequent addition of lard oil (triglycerides) resulted in rapid formation of the
desired wax esters in ca. 80–90% yields. In preliminary studies, the same wax esters were prepared by a more circuitous route.
The alcoholates were decomposed completely with urea, the fatty alcohols were liberated, and they then were esterified with
free lard oil acids. Similarly treated were a blend of lard, coconut and crambe oils, fractionated tallow, and a commercial
grade oleic acid.
Presented at the AOCS Meeting, New Orleans, April 1973.
ARS, USDA. 相似文献
2.
Wax composition of sunflower seed oils 总被引:1,自引:3,他引:1
Amalia A. Carelli Lorna M. Frizzera Pedro R. Forbito Guillermo H. Crapiste 《Journal of the American Oil Chemists' Society》2002,79(8):763-768
Waxes are natural components of sunflower oils, consisting mainly of esters of FA with fatty alcohols, that are partially
removed in the winterization process during oil refining. The wax composition of sunflower seed as well as the influence of
processing on the oil wax concentration was studied using capillary GLC. Sunflower oils obtained by solvent extraction from
whole seed, dehulled seed, and seed hulls were analyzed and compared with commercial crude and refined oils. The main components
of crude sunflower oil waxes were esters having carbon atom numbers between 36 and 48, with a high concentration in the C40−C42 fraction. Extracted oils showed higher concentrations of waxes than those obtained by pressing, especially in the higher
M.W. fraction, but the wax content was not affected significantly by water degumming. The hull contribution to the sunflower
oil wax content was higher than 40 wt%, resulting in 75 wt % in the crystallized fraction. The oil wax content could be reduced
appreciably by hexane washing or partial dehulling of the seed. Waxes in dewaxed and refined sunflower oils were mainly constituted
by esters containing fewer than 42 carbon atoms, indicating that these were mostly soluble and remained in the oil after processing. 相似文献
3.
Limanathes douglasii seed oil glycerides contain fatty acids which predominantly (97%) have 20 or more carbon atoms. Fatty acids were prepared
by saponification; fatty alcohols, by sodium reduction of the glycerides; and liquid wax esters, byp-toluenesulfonic acid-catalyzed reaction of the fatty acids with the fatty alcohols. Solid waxes were prepared by hydrogenation
of the glyceride oil and of the wax esters. Chemical and physical constants were determined forLimnanthes douglasii seed oil and its derivatives. The liquid wax esters had properties very similar to those of jojoba (Simmondsia chinensis) seed oil. The solid hydrogenated wax ester was identical in physical appearance and melting point to hydrogenated jojoba
seed oil.
A laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, USDA. 相似文献
4.
Gayland F. Spencer 《Journal of the American Oil Chemists' Society》1979,56(6):642-646
Wax esters from winterized sperm whale oil were separated according to degree of unsaturation and then analyzed by gas chromatography-mass
spectrometry. The combinations of fatty alcohols and acids making up the wax esters of each chain length were determined.
Octadecenyl octadecenoate was the most abundant wax ester (14%), followed by octadecenyl hexadecenoate (10%). Over 240 different
wax esters were detected and quantitated.
Presented at the AOCS Meeting in San Francisco, 1979. 相似文献
5.
D. H. Buisson D. R. Body G. J. Dougherty L. Eyres P. Vlieg 《Journal of the American Oil Chemists' Society》1982,59(9):390-395
The lipid fraction of the deep water fish species orange roughy (Hoplostetbus atlanticus), black oreo (Allocyttus sp.) and small spined oreo (Pseudocyttus maculatus) had wax esters with even carbon numbers over the range C30 to C46 as the major components. The component acids and alcohols of the wax ester fraction were analyzed by gas liquid chromatography
and compared with those of jojoba and sperm whale oils. Orange roughy oil was refined and deodorized and its chemical, physical
and mechanical properties were determined. Hydrogenation of orange roughy oil produced a range of white crystalline waxes
with melting points between 34 and 66 C. The characteristics of these waxes were very similar to those of hydrogenated jojoba
oil and spermaceti. Lubricant tests performed on sulfurized orange roughy oil indicated it is comparable to sulfurized jojoba
and sperm whale oils as an extreme-pressure additive in lubricants. The results show a sound technical basis on which to consider
an industry based on orange roughy oil and the oreo oils as replacements for sperm whale oil and as substitutes for jojoba
oil. Applications for the oil could be in the cosmetic and high-grade lubricant fields, the waxes in the polish, textile,
cosmetic and pharmaceutical industries and the sulfurized derivative of orange roughy oil in the lubricant industry. 相似文献
6.
Thomas K. Miwa 《Journal of the American Oil Chemists' Society》1971,48(6):259-264
HCl-catalyzed ethanolysis followed by saponification readily surmounts the resistance of long chain wax esters to direct hydrolysis
by alkali. Additionally, choosing ethyl instead of methyl esters allows baseline separations between long-chain alcohols and
corresponding esters in gas liquid chromatographic (GLC) analysis of total alcohol and acid components before saponification.
Liquid wax esters were analyzed on a temperature-programmed 3% OV-1 silicone column. Geographical and genetic effects on the
variability of jojoba oil composition were investigated with five different seed samples. Major constituents in jojoba seed
oil from shrubs in the Arizona deserts, as indicated by GLC analyses of oil, ethanolysis product, isolated fatty alcohols
and methyl esters of isolated fatty acids, were C40 wax ester 30%, C42 wax ester 50% and C44 wax ester 10%; octadecenoic acid 6%; eicosenoic acid 35%, docosenoic acid 7%, eicosenol 22%, docosenol 21% and tetracosenol
4%. Oil from smaller leaved prostrate plants growing along California’s oceanside showed a slight tendency toward higher molecular
size than oils from the California desert and Arizona specimens. The wax esters are made up of a dispro-portionately large
amount of docosenyl eicosenoate and are not a random combination of constituent acids and alcohols.Lunaria annua synthetic wax ester oil was used as a model for evaluating the analytical procedures.
Presented at the AOCS Meeting, Chicago, September 1970
No. Utiliz, Res. Dev. Div., ARS, USDA. 相似文献
7.
Methyl and ethyl monoalkyl esters of various vegetable oils were produced for determining the effects of type of alcohol and
fatty acid profile of the vegetable oil on the lubricity of the ester. Four methyl esters and six ethyl esters were analyzed
for wear properties using the American Society for Testing and Materials method D 6079, Evaluating Lubricity of Diesel Fuels
by the High-Frequency Reciprocating Rig. Ethyl esters showed noticeable improvement compared to methyl esters in the wear
properties of each ester tested. No correlation was found between lubricity improvement and fatty acid profile of the ester,
except that esters of castor oil had improved lubricity over other oils with similar carbon chain-length (C18) fatty acids. 相似文献
8.
Crambe abyssinica andLunaria annua, members of the Cruciferae family, have seed oil glycerides containing ca. 55–65% of C22 and C24 unsaturated fatty acids. Fatty acids were prepared by saponification; fatty alcohols, by sodium reduction of glycerides;
liquid wax esters, byp-toluenesulfonic acid-catalyzed reaction of fatty acids with fatty alcohols; and methyl esters, by reaction of fatty acids
with diazomethane. Solid hydrogenated glyceride oils and wax esters were compared with several commercial waxes. Chemical
and physical constants were determined for the seed oils and their derivatives. Position of unsaturation in theCrambe fatty acids was determined by gas chromatographic analysis of the permanganate-periodate degradation products. The major
dicarboxylic acid was brassylic (C13), proving the docosenoic acid to be erucic.
Presented in part at the AOCS meeting in New Orleans, La., 1962.
A laboratory of the No. Utiliz. Res. & Dev. Div., ARS, U.S.D.A. 相似文献
9.
Amalia A. Carelli Erica B. Bäumler Liliana N. Ceci 《European Journal of Lipid Science and Technology》2012,114(11):1312-1319
In this work, a modified International Olive Council (IOC) method for wax determination involving a double‐adsorbent layer of silica gel and silver nitrate‐impregnated silica gel is presented (SN method). Column chromatography by the SN method did not show retention of wax esters standards with an even number of carbon atoms (C34–C44), observing recovery percentages higher than 90% even for unsaturated wax esters. All wax fractions were lower by the SN method than by the IOC method, resulting in a percentage decrease in the total wax content (olive oils: 20–50%, crude sunflower oil: 38%, crude soybean oil: 58% and crude grape seed oil: 13%). Olive oils analysed by the SN method showed increases of up to 27% in C40 relative percentage with respect to the IOC method. Additionally, decreases were observed by the SN method in the relative percentages for odd‐carbon atom waxes for the seed oils in comparison to the IOC method (crude sunflower oil: 27%, crude soybean oil: 28% and crude grape seed oil: 13%). The main advantages of the proposed modification consist in its easy implementation and a better determination of wax esters (C34–C60) by controlling their complete recovery and removing interfering substances. The method is suitable for quality control and for authentication of olive oil and seed oils as well as in processing monitoring. Practical applications: The proposed method is useful in the quality, authentication and processing control of fruit and seed oils. Moreover, it can be an important tool for vegetable oil industries to control the efficiency of the wax separation process to prevent turbidity in the refined oil. 相似文献
10.
Chemical structure of long-chain esters from “sansa” olive oil 总被引:1,自引:0,他引:1
Giorgio Bianchi Aldo Tava Giovanna Vlahov Nicoletta Pozzi 《Journal of the American Oil Chemists' Society》1994,71(4):365-369
The major objective of this study was to determine the chemical structure of long-chain esters present in lower-grade olive
oil. The classes of esters composing the hexanediethyl ether (99∶1) extract of the wax fraction from a pomace olive oil were:
(i) esters of oleic acid with C1−C6 alcohols, (ii) esters of oleic acid with long-chain aliphatic alcohols in the range C22−C28 and (iii) benzyl alcohol esters of the very long-chain saturated fatty acids C26 and C28. The analysis and the structure assignments were carried out by gas chromatography coupled with mass spectrometry and by
comparison with synthetic authentic model compounds. This work provided precise data on the chemical nature of the wax esters
present in olive oil and should represent a means to detect adulteration of higher-grade olive oil with less expensive pomace
olive oil and seed oils. 相似文献
11.
The fatty acids recovered from the triglycerides and wax esters of common northwest Atlantic copepods are compared with the
fatty acids of wax esters recovered intact from certain fish skin and body lipid, and from commercial fish oils. The fish
species, herring, capelin and mackerel, all feed on copepods, and many resemblances of the copepod lipid fatty acids to those
of a previous analysis of similar copepods suggest that the basic dietary fat input for these fish may be quite constant.
The two copepod fatty acid analyses differed quantitatively in triglyceride 20∶1 and 22∶1 and also in 20∶5ω3 and 22∶6ω3, confirming
the primary role of the wax esters in copepods. Selectivity factors are discussed in comparing the copepod wax ester fatty
acids with the fatty acids of the wax esters recovered intact from the fish lipids and oils. The basic role of copepods in
supplying all types of fatty acids to fish depot fats is considered to be strongly supported by these findings. 相似文献
12.
Konrad Grob Mauro Lanfranchi Cario Mariani 《Journal of the American Oil Chemists' Society》1990,67(10):626-634
The analysis of the fatty alcohols, the wax esters, the free and the esterified sterols, as well as that of minor components
provides a wealth of information about the quality of an oil or fat, its pretreatment and admixture with other oils. Some
results obtained by an easy, nearly fully-automated method are shown for olive oils. More specific information is obtained
than by the previous saponification methods. 相似文献
13.
Biodiesel is gaining more and more importance as an attractive fuel due to the depleting fossil fuel resources. Chemically biodiesel is monoalkyl esters of long chain fatty acids derived from renewable feed stock like vegetable oils and animal fats. It is produced by transesterification in which, oil or fat is reacted with a monohydric alcohol in presence of a catalyst to give the corresponding monoalkyl esters. This article reports experimental data on the production of fatty acid methyl esters from vegetable oils, soybean and cottonseed oils using sodium hydroxide as alkaline catalyst. The variables affecting the yield and characteristics of the biodiesel produced from these vegetable oils were studied. The variables investigated were reaction time (1-3 h), catalyst concentration (0.5-1.5 w/wt%), and oil-to-methanol molar ratio (1:3-1:9). From the obtained results, the best yield percentage was obtained using a methanol/oil molar ratio of 6:1, sodium hydroxide as catalyst (1%) and 60 ± 1 °C temperature for 1 h. The yield of the fatty acid methyl ester (FAME) was determined according to HPLC. The composition of the FAME was determined according to gas chromatography. The biodiesel samples were physicochemically characterized. From the results it was clear that the produced biodiesel fuel was within the recommended standards of biodiesel fuel. 相似文献
14.
This work demonstrates that Cu- B2O3/SiO2 is an effective catalyst for synthesis of fatty alcohols from hydrogenolysis of fatty acid esters. Boron oxide not only acts
as a textural promoter to increase the dispersion of copper, but also as a structural promoter to decrease the activation
energy of hydrogenolysis by 10 kJ/mol. The optimum loading of boron oxide doped is around 6.4 wt%. This chromium-free copper
catalyst is seven times as active as the commercial copper chromite (Engelhard Cu-1234E) in the hydrogenolysis of methyl esters
at 240°C, 110 bar. Cu- B2O3(6.4%)/SiO2 is a promising catalyst for lower pressure (<150 bar) hydrogenolysis processes.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
Two sperm whale oils from the northern hemisphere and two from the southern hemisphere were fractionated. Triglyceride and wax esters were examined for fatty acids and alcohols with monoethylenic unsaturation bearing a methyl branch on an ethylenic carbon. The 7-methyl-7-hexadecenoic acid (0.37-1.37%) was accompanied by the corresponding alcohol (0.28-0.72%), but these materials were not accompanied by shorter chain homologues. The 7-methyl-6-hexadecenoic acid was relatively less important (0.23-0.68%), but was accompanied by 5-methyl-4-hexadecenoic acid (0.10-0.39%), and a partially identified C13 compound. Chromatographic properties on silver nitrate impregnated silicic acid TLC and on three GLC liquid phases are reported. 相似文献
16.
In recent years, vegetable oils, as renewable raw materials, became a promising feedstock for chemicals and biodiesel production. The main products derived from oils are esters of fatty acids, especially methyl esters, obtained by their transesterification with methanol, in presence of acid or alkaline catalysts. The use of such catalysts implies the need for washing operations, which leads to environmental pollution. In the present paper, the response surface methodology based on a central composite design, has been developed to optimize the process of transesterification of corn oil. Ba(OH)2 in presence of diethyl ether was used as catalyst. A quadratic polynomial equation was obtained. It correlates the reaction parameters [methanol/oil molar ratio (x r), reaction time (x t) and catalyst concentration (x c)] with methyl esters yield. Analysis of variance analysis showed that only methanol/oil molar ratio and catalyst concentration have had the most significant influences on the conversion. The maximum methyl esters yield was obtained using the following optimum parameters: methanol/corn oil ratio of 11.32, reaction time of 118 min and catalyst concentration of 3.6 wt%. 相似文献
17.
The wax esters of sperm whale head oil have been characterized by gas-liquid chromatography on an APOLAR 10C column according
to their carbon number and number of double bonds. The novel technique permits the direct quantitative analysis of saturated
and unsaturated wax esters. 相似文献
18.
Arne Staby Christina Borch-Jensen Steen Balchen Jørgen Mollerup 《Journal of the American Oil Chemists' Society》1994,71(4):355-359
Various natural and processed fish oil triglyceride mixtures have been analyzed by capillary supercritical fluid chromatography
(SFC). The analyses were performed on nonpolar columns to separate the components by lipid class and by the number of carbon
atoms. The compounds separated included free fatty acids, squalene, α-tocopherol, cholesterol, wax esters, cholesteryl esters,
di- and triglycerides. This kind of analysis is not possible by gas chromatography or high-performance liquid chromatography
methods without prior treatment of the fish oil, making SFC superior for this application. Applications of SFC to fish oils
are given, including a control analysis of the various process steps in the refining of a fish oil, analysis of a lipase-catalyzed
transesterification of a fish oil and the detection of polymeric artifacts. 相似文献
19.
Biodiesel production from high FFA rubber seed oil 总被引:7,自引:0,他引:7
Currently, most of the biodiesel is produced from the refined/edible type oils using methanol and an alkaline catalyst. However, large amount of non-edible type oils and fats are available. The difficulty with alkaline-esterification of these oils is that they often contain large amounts of free fatty acids (FFA). These free fatty acids quickly react with the alkaline catalyst to produce soaps that inhibit the separation of the ester and glycerin. A two-step transesterification process is developed to convert the high FFA oils to its mono-esters. The first step, acid catalyzed esterification reduces the FFA content of the oil to less than 2%. The second step, alkaline catalyzed transesterification process converts the products of the first step to its mono-esters and glycerol. The major factors affect the conversion efficiency of the process such as molar ratio, amount of catalyst, reaction temperature and reaction duration is analyzed. The two-step esterification procedure converts rubber seed oil to its methyl esters. The viscosity of biodiesel oil is nearer to that of diesel and the calorific value is about 14% less than that of diesel. The important properties of biodiesel such as specific gravity, flash point, cloud point and pour point are found out and compared with that of diesel. This study supports the production of biodiesel from unrefined rubber seed oil as a viable alternative to the diesel fuel. 相似文献
20.
Maurus Biedermann Paul Haase‐Aschoff Konrad Grob Dr. 《European Journal of Lipid Science and Technology》2008,110(12):1084-1094
The wax ester fraction of various plant oils was isolated by normal‐phase HPLC (NPLC) on‐line coupled to GC via the on‐column interface and applying concurrent eluent evaporation. The esters were analyzed by on‐line NPLC‐GC‐MS and by comprehensive two‐dimensional GC with flame ionization detection (GC×GC‐FID) off‐line combined with NPLC‐GC. GC×GC‐FID enables to group the various classes of wax esters, in particular the phytol esters, geranylgeraniol esters and the straight‐chain esters of palmitic acids and the unsaturated C18 acids. Optimization of the GC×GC columns and the conditions must take into account the limited thermostability of the diterpene esters. Chromatograms are shown for a range of oils, with particular focus on the various classes of wax esters in olive oil and the geranylgeraniol esters 22:0 and 24:0 in a variety of oils. 相似文献