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1.
Steven L. Johansen Arunthathi Sivasothy Michael K. Dowd Peter J. Reilly Earl G. Hammond 《Journal of the American Oil Chemists' Society》1996,73(10):1275-1286
Alkaline extracts (soapstocks) from canola, corn, cottonseed, peanut, soybean, and sunflower oil refining were acidified,
and identities and concentrations of the low-molecular weight organic components of the resulting acid waters were determined
by gas chromatography, followed by mass spectroscopy, and by high-performance liquid chromatography. The main components of
each acid water sample, in order of decreasing concentration and after omitting the fermentation product lactic acid, were
phosphoric acid, α-glycerophosphate, and glycerol from canola;myo-inositol, phosphoric acid, α-glycerophosphate andmyo-inositol-1-phosphate from corn; glycerol, α-glycerophosphate,myo-inositol-1-phosphate, and β-glycerophosphate from cottonseed; phosphoric acid, glycerol, andmyo-inositol from peanut; α-glycerophospho-1-myo-inositol,myo-inositol-1-phosphate, α-glycerophosphate, and glycerol from soybean; and α-glycerophosphate, glycerol,myo-inositol-1-phosphate, and β-glycerophosphate from sunflower. 相似文献
2.
Simple alkyl FA esters have numerous uses, including serving as biodiesel, a fuel for compression ignition (diesel) engines.
The use of acid-catalyzed esterification for the synthesis of FAME from acid oil, a by-product of edible vegetable oil refining
that is produced from soapstock, was investigated. Soybean acid oil contained 59.3 wt% FFA, 28.0 wt% TAG, 4.4 wt% DAG, and
less than 1% MAG. Maximum esterification occurred at 65°C and 26 h reaction at a molar ratio of total FA/methanol/sulfuric
acid of 1∶15∶1.5. Residual unreacted species under these conditions, as a fraction of their content in unesterified acid oil,
were FFA, 6.6%; TAG, 5.8%; and DAG, 2.6%. This corresponds to estimated concentrations of FFA, 3.2%; TAG, 1.3%; and DAG, 0.2%,
on a mass basis, in the ester product. In an alternative approach, the acylglycerol species in soapstock were saponified prior
to acidulation. High-acid (HA) acid oil made from this saponified soapstock had an FFA content of 96.2 wt% and no detectable
TAG, DAG, or MAG. Optimal esterification conditions for HA acid oil at 65°C were a mole ratio of FFA/methanol/acid of 1∶1.8∶0.17,
and 14 h incubation. FAME recovery under these conditions was 89% of theoretical, and the residual unesterified FFA content
was approximately 20 mg/g. This was reduced to 3.5 mg/g, below the maximum FFA level allowed for biodiesel, by washing with
NaCl, NaHCO3, and Ca(OH)2 solutions. Alternatively, by subjecting the unwashed ester layer to a second esterification, the FFA level was reduced to
less than 2 mg/g. The acid value of this material exceeded the maximum allowed for biodiesel, but was reduced to an acceptable
value by a brief wash with 0.5 N NaOH. 相似文献
3.
T. Gallina Toschi M. F. Caboni G. Penazzi G. Lercker P. Capella 《Journal of the American Oil Chemists' Society》1993,70(10):1017-1020
Eight samples of cashew nut oil were assayed, and the component triacylglycerols, fatty acids and several unsaponifiable compounds
were analyzed by gas chromatography (GC) and high-performance liquid chromatography (HPLC). Total lipid amount, unsaponifiable
percentage, fatty acids, sterols, triterpene alcohols and tocopherols are reported here. The combination of GC and HPLC enhanced
the resolution of compound classes. 相似文献
4.
5.
The soapstock of a mixture of marine fish was used as the raw material to produce the biodiesel in this study. The soapstock was collected from discarded fish products. Crude fish oil was squeezed from the soapstock of the fish and refined by a series of processes. The refined fish oil was transesterified to produce biodiesel. The fuel properties of the biodiesel were analyzed. The experimental results showed that oleic acid (C18:1) and palmitic acid (C16:0) were the two major components of the marine fish-oil biodiesel. The biodiesel from the mixed marine fish oil contained a significantly greater amount of polyunsaturated fatty acids than did the biodiesel from waste cooking oil. In addition, the marine fish-oil biodiesel contained as high as 37.07 wt.% saturated fatty acids and 37.3 wt.% long chain fatty acids in the range between C20 and C22. Moreover, the marine fish-oil biodiesel appeared to have a larger acid number, a greater increase in the rate of peroxidization with the increase in the time that it was stored, greater kinematic viscosity, higher heating value, higher cetane index, more carbon residue, and a lower peroxide value, flash point, and distillation temperature than those of waste cooking-oil biodiesel. 相似文献
6.
Michael J. Haas Scott Bloomer Karen Scott 《Journal of the American Oil Chemists' Society》2000,77(4):373-379
We report a simple method that efficiently esterifies the fatty acids in soapstock, an inexpensive, lipid-rich by-product
of edible oil production. The process involves (i) alkaline hydrolysis of all lipid-linked fatty acid ester bonds and (ii)
acid-catalyzed esterification of the resulting fatty acid sodium salts. Step (i) completely saponified all glycerides and
phosphoglycerides in the soapstock. Following water removal, the resulting free fatty acid sodium salts were rapidly and quantitatively
converted to fatty acid methyl esters (FAME) by incubation with methanol and sulfuric acid at 35°C and ambient pressure. Minimum
molar reactant ratios for full esterification were fatty acids/methanol/sulfuric acid of 1∶30∶5. The esterification reaction
was substantially complete within 10 min and was not inhibited by residual water contents up to ca. 10% in the saponified soapstock. The product FAME contained >99% fatty acid esters, 0% triglycerides, <0.05% diglycerides,
<0.1% monoglycerides, and <0.8% free fatty acids. Free fatty acid levels were further reduced by washing with dilute sodium
hydroxide. Free and total glycerol were <0.01 and <0.015%, respectively. The water content was <0.04%. These values meet the
current specifications for biodiesel, a renewable substitute for petroleum-derived diesel fuel. The identities and proportions
of fatty acid esters in the FAME reflected the fatty acid content of soybean lipids. Solids formed during the reaction contained
69.1% ash and 0.8% protein. Their sodium content indicated that sodium sulfate was the prime inorganic component. Carbohydrate
was the predominant organic constituent of the solid. 相似文献
7.
Differential scanning calorimetric analysis of edible oils: Comparison of thermal properties and chemical composition 总被引:2,自引:11,他引:2
The thermal profiles of 17 edible oil samples from different plant origins were examined by differential scanning calorimetry
(DSC). Two other confirmatory analytical techniques, namely gas-liquid chromatography (GLC) and high-performance liquid chromatography
(HPLC), were used to determine fatty acid (FA) and triacylglycerol (TAG) compositions. The FA and TAG compositions were used
to complement the DSC data. Iodine value (IV) analysis was carried out to measure the degree of unsaturation in these oil
samples. The DSC melting and crystallization curves of the oil samples are reported. The contrasting DSC thermal curves provide
a way of distinguishing among these oil samples. Generally, the oil samples with a high degree of saturation (IV<65) showed
DSC melting and crystallization profiles at higher temperature regions than the oil samples with high degree of unsaturation
(IV>65). Each thermal curve was used to determine three DSC parameters, namely, onset temperature (T
o
), offset temperature (T
f
) and temperature range (difference between T
o
and T
f
). Reproducibility of DSC curves was evaluated based on these parameters. Satisfactory reproducibility was achieved for quantitation
of these DSC parameters. The results show that T
o
of the crystallization curve and T
f
of the melting curve differed significantly (P<0.01) in all oil samples. Our observations strengthen the premise that DSC is an efficient and accurate method for characterizing
edible oils. 相似文献
8.
9.
Antonio Romero Carmen Cuesta Francisco J. Sánchez-Muniz 《Journal of the American Oil Chemists' Society》1998,75(2):161-167
Frying stability of sunflower oil (SO) with 23% oleic acid and 61% linoleic acid, and of high-oleic acid sunflower oil (HOSO)
with 74% oleic acid and 13% linoleic acid was studied during 20 discontinuous deep-fat fryings of various frozen foods, with
or without frequent replenishment of the used oil with fresh oil. Alterations of both oils were measured by column, gas-liquid
and high-performance size-exclusion chromatography. Total polar content and compounds, related to thermoxidative changes,
and diacylglycerides, related to hydrolytic changes, increased in all oils during frying but reached higher levels in SO than
in HOSO. Nevertheless, the increased levels of diacylglycerides observed may result from the frozen potatoes prefried in palm
oil. Oleic acid in HOSO and linoleic acid in SO significantly decreased, but the fatty acid modifications that occurred during
the repeated fryings were not only related to thermoxidative alteration but also to interactions between the bath oil and
the fat in the fried products. Data from this study also indicated that HOSO performed more satisfactorily than SO in repeated
fryings of frozen foods. Moreover, frequent addition of fresh oil throughout the deep-frying process minimized thermoxidative
and hydrolytic changes in the frying oils and extended the frying life of the oils. 相似文献
10.
Extraction and purification of oryzanol from rice bran oil and rice bran oil soapstock 总被引:2,自引:0,他引:2
A. V. Narayan R. S. Barhate K. S. M. S. Raghavarao 《Journal of the American Oil Chemists' Society》2006,83(8):663-670
Oryzanol is an important value-added co-product of the rice and rice bran-refining processes. The beneficial effects of oryzanol
on human health have generated global interest in developing facile methods for its separation from rice bran oil soapstock,
a by-product of the chemical refining of rice bran oil. In this article we discuss the isolation of oryzanol and the effect
that impurities have on its extraction and purification. Presented are the principles behind the extraction (solid-liquid
or liquid-liquid extraction, and other methods) of these unit operations covered in selected patents. Methods other than extraction
such as crystallization or precipitation-based or a combination of these unit operations also are reviewed. The problems encountered
and the ways to solve them during oryzanol extraction, such as prior processing and compositional variation in soapstock,
resistance to mass transfer, moisture content and the presence of surface active components, which cause emulsion formation,
are examined. Engineering inputs required for solving problems such as saponification, increasing mass transfer area, and
drying methods are emphasized. Based on an analysis of existing processes, those having potential to work in large-scale extraction
processes are presented. 相似文献
11.
Francie G. Dunlap Pamela J. White Linda M. Pollak 《Journal of the American Oil Chemists' Society》1995,72(9):989-993
The fatty acid composition of corn oil can be altered to meet consumer demand for “healthful” fats. The first step in altering
the oils is to survey existing corn breeding materials for fatty acid composition. The Latin American Maize Project (LAMP),
an international program designed to evaluate the agronomic characteristics of maize accessions in Latin American and U.S.
germplasm banks for future use, provides useful starting materials. LAMP was based on the cooperative efforts of 12 countries.
In a two-stage evaluation, the project identified the highest-yielding open-pollinated top 20% of populations, then approximately
the top 5% of those 20%. Twenty of the populations from four countries with temperate climates were randomly selected for
fatty acid analysis. The populations were from United States, Chile, Argentina, and Uruguay. Fifty S1 lines from each population were randomly chosen for analysis for a total of 1,000 genotypes sampled. Statistical differences
in fatty acid composition were computed among the 20 populations and among the four countries. The findings showed a wide
range of fatty acid profiles present in unadapted, elite corn breeding materials with ranges for each fatty acid as follows:
palmitic acid, 6.3–18.2%; stearic acid, 0.9–4.5%; oleic acid, 18.5–46.1%; linoleic acid, 36.6–66.8%; linolenic acid, 0.0–2.0%;
and arachidic acid, 0.0–1.4%. Several populations were significantly different from the others. Some lines had unusual fatty
acid compositions, including one with 8.3% total saturates and another with 20.2% total saturates. This study shows that existing
corn breeding materials could be used to produce high- and low-saturate oils, but other methods would probably be required
to produce a high-oleic corn oil. 相似文献
12.
William W. Christie 《European Journal of Lipid Science and Technology》2002,104(1):69-70
Fatty acid pyrrolidides have been found to have unusual gas chromatographic properties on a polar stationary phase of the Carbowax type. In particular, exceptional resolution of positional isomers was achieved, and in contrast to methyl esters, unsaturated isomers with double bonds in position 5 or earlier eluted before the corresponding saturated fatty acid derivative. 相似文献
13.
Soapstock (SS) is a by-product of the extraction of oilseeds to produce edible oils. Annual U.S. production exceeds one-half
million tons. A representative sample of SS consists of 45.1% water, 10.0% free fatty acids, 10.1% triglycerides, 1.8% diglycerides,
3.6% phosphatidylethanolamine, 2.2% phosphatidylinositol, 2.7% phosphatidylcholine, 14.0% solvent-insolubles and 10.5% other
material, which was not characterized. A process has been developed that sequentially employs a nonenzymatic and an enzymatic
step to convert the lipid-linked and the free fatty acids of SS to the esters of monohydric alcohols. The first step of the
process employed alcohol and potassium hydroxide to transesterify the glyceride-and phosphoglyceride-linked fatty acids of
the substrate. Because water inhibited the reaction, it was necessary that the SS be dried before use. Nonetheless, even with
some batches of SS with water contents below 1% (weight basis), ester hydrolysis accompanied esterification. Each of five
examined simple primary alcohols participated effectively in the transesterification reaction, which proceeded rapidly at
room temperature and was essentially complete within 1 h. The average ratio of transesterification to hydrolysis in four examined
small primary alcohols was 4:1. However, in methanol this value was 99:1 due to the virtual absence of hydrolysis. Significant
transesterification by a secondary alcohol (isopropanol) did not occur at room temperature. The minimum effective molar ratio
of alcohol to lipid-linked fatty acids was 20:1. The minimum effective concentration of KOH was between 0.10 and 0.15N. The
efficiency of the transesterification reaction exceeded 90% of theoretical maximum. The second step of the process involves
lipase-mediated esterification of the free fatty acids in the preparation that are not esterified by the alkaline transesterfication.
Of four lipase preparations examined (Novo Lipozyme IM 20 and SP435, and Amano PS30 and CE), only SP-435 catalyzed significant
esterification of the free fatty acids. The reaction was not catalyzed by heat-denatured enzyme. In the pH range between 6
and 13.5, the enzyme reaction proceeded best at pH 6, although also well at pH 7. The optimal water concentration was 0.70%
(vol/vol). At an enzyme dosage of 1.1% (weight basis, relative to the dry weight of SS present) under optimal conditions and
at 42°C, 63% of the free fatty acids in a post-alcoholysis mixture were enzymatically esterified. The addition of molecular
sieves did not increase esterification, which was probably retarded by the high viscosities of the reactions. Under the optimal
conditions identified here, the degree of conversion of the fatty acids in SS to simple alkyl esters by the combined reaction
scheme was 81%. Opportunities exist for further optimization of these reactions. 相似文献
14.
V. Spitzer S. A. de L. Bordignon E. P. Schenkel F. Marx 《Journal of the American Oil Chemists' Society》1994,71(12):1343-1348
In addition to some usual fatty acids, the seed oil ofJodina rhombifolia (Santalaceae) contains nine acetylenic fatty acids [9-octadecynoic acid (stearolic acid) (1.1%),trans-10-heptadecen-8-ynoic acid (pyrulic acid) (20.1%), 7-hydroxy-trans-10-heptadecen-8-ynoic acid (2.3%),trans-10,16-heptadecadien-8-ynoic acid (0.7%), 7-hydroxy-trans-10,16-heptadecadien-8-ynoic acid (0.1%),trans-11-octadecen-9-ynoic acid (ximenynic acid) (20.3%), 8-hydroxy-trans-11-octadecen-9-ynoic acid (12.2%),trans-11,17-octadecadien-9-ynoic acid (1.5%), 8-hydroxy-trans-11,17-octadecadien-9-ynoic acid (1.3%), 9-hydroxystearic acid (<0.1%) and 9,10-epoxystearic acid (0.7%)]. The fatty acids
have been analyzed by gas chromatography/mass spectrometry of their methyl ester and 4,4-dimethyloxazoline derivatives. The
hydroxy fatty acid methyl esters have been examined also as trimethyl-silyl ethers. Furthermore, the fatty acid methyl esters
(FAME) have been fractionated according to their polarity (FAME-A: nonhydroxy; FAME-B: hydroxy fatty acids) and to their degree
of unsaturation (FAME-A1/A2; FAME-B1/B2) by preparative thin-layer chromatography and argentation chromatography, respectively.
All of these fractions have been analyzed by ultraviolet and infrared spectroscopy, and the fractions FAME-A and FAME-B have
been analyzed further by nuclear magnetic resonance (1H,13C, 2D H/C, attached proton test) spectroscopy and gas chromatography/mass spectrometry.
This work is dedicated to the 65th birthday of Prof. Dr. K. Pfeilsticker, Institut of Food Science, University Bonn (Germany). 相似文献
15.
V. Petrauskaitè W. F. De Greyt M. J. Kellens 《Journal of the American Oil Chemists' Society》2000,77(6):581-586
In the present study, neutral oil loss (distillative and mechanical carry-over) during physical refining of coconut oil was
quantified. Neutral oil loss seems to depend on both the crude oil quality and the process conditions during deodorization.
The distillation of volatile glyceridic components (monoand diglycerides), originally present in the crude oil, was confirmed
as the major cause for the neutral oil loss. The amount of these volatile components in crude coconut oils cannot be derived
as such from the initial free fatty acid content. A lower deodorization pressure with less sparge steam resulted in a larger
neutral oil loss than a higher pressure with more steam. A “deodorizability” test on a laboratory scale under standardized
conditions (temperature=230°C, pressure=3 mbar, time=60 min, sparge steam=1%), to evaluate crude oil quality and to obtain
a more accurate prediction of the expected neutral oil loss and free fatty acid content in the fatty acid distillate, is described. 相似文献
16.
17.
Reena Rao S. Divakar Belur R. Lokesh 《Journal of the American Oil Chemists' Society》2002,79(6):555-560
The preference of lipase (EC 3.1.1.3) from Rhizomucor miehei in the incorporation of 11 FA, ranging from C10∶0 to C22∶6, into coconut oil TAG during acidolysis was studied by applying
the Plackett-Burman experimental design. Enzymatic acidolysis reactions were carried out in hexane at 37°C for 48 h with coconut
oil (0.1 M) and a mixture of 11 FA at a TAG to FA molar ratio of 1∶1. Lipase was used at the 5 wt% level. The incorporation
of FA into coconut oil TAG was determined by GC. The lipase showed preference for long-chain saturated FA for incorporation
into coconut oil TAG. The FA with 18 carbon atoms showed a high incorporation rate (18∶1>18∶1>18∶3). The lipase showed the
least preference for the incorporation of 12∶0, which occurs in maximal concentration (46%), whereas the most preferred FA,
18∶0, occurs at a very low concentration (<2%) in coconut oil. The overall preference of lipase for the incorporation of different
FA into coconut oil TAG was 18∶0>18∶2, 22∶0>18∶1, 18∶3, 14∶0, 20∶4, 22∶6>16∶0>12∶0≫10∶0. 相似文献
18.
Michael H. Gordon Ibrahim Abdul Rahman 《Journal of the American Oil Chemists' Society》1991,68(8):574-576
The effect of various processing procedures on the composition and oxidative stability of coconut oil has been studied. The
crude oil is relatively stable but major reductions in oxidative stability occur during the bleaching of oil degummed with
phosphoric acid; during alkali refining; during the deodorization of oil degummed with citric acid and bleached; and during
the deodorization of oil processed with a combined phosphoric acid degumming and bleaching operation. The reasons for the
loss of oxidative stability during processing are discussed with reference to changes in the composition of the oil. Residual
traces of citric acid or phosphoric acid play an important role in stabilizing processed oils. The tocopherol content is also
important, although no additional stabilization of the oil occurs on adding levels of tocopherol above those present naturally
in the crude oil. A combined phosphoric acid degumming and bleaching process leads to smaller losses of tocopherols than sequential
treatments. 相似文献
19.
Purification of polyunsaturated fatty acid esters from tuna oil with supercritical fluid chromatography 总被引:7,自引:0,他引:7
M. Alkio C. Gonzalez M. Jäntti O. Aaltonen 《Journal of the American Oil Chemists' Society》2000,77(3):315-321
The technical and economic feasibility of producing docosahexaenoic acid (DHA)- and eicosapentaenoic acid (EPA)-ethyl ester concentrates from transesterified tuna oil using supercritical fluid chromatography (SFC) was studied. A systematic experimental procedure was used to find the optimal values for process parameters and the maximal production rate. DHA ester concentrates up to 95 wt% purity were obtained in one chromatographic step with SFC, using CO2 as the mobile phase at 65°C and 145 bar and octadecyl silane-type reversed-phase silica as the stationary phase. DHA ester, 0.85 g/(kg stationary phase · h) and 0.23 g EPA ester/(kg stationary phase · h) can be simutaneously produced at the respective purities of 90 and 50 wt%. The process for producing 1,000 kg DHA concentrate and 410 kg EPA concentrate per year requires 160 kg stationary phase and 2.6 tons/h carbon dioxide eluant recycle. The SFC operating cost is U.S. $550/kg DHA and EPA ethyl ester concentrate. 相似文献
20.
Francie G. Dunlap Pamela J. White Linda M. Pollak Thomas J. Brumm 《Journal of the American Oil Chemists' Society》1995,72(9):981-987
The fatty acid composition of corn oil can be altered to meet consumer demands for “healthful” fats (i.e., lower saturates
and higher monounsaturates). To this end, a survey of 418 corn hybrids and 98 corn inbreds grown in Iowa was done to determine
the fatty acid composition of readily-available, adapted, elite corn breeding materials. These materials are those used in
commercial hybrid production. Eighty-seven hybrids grown in France (18 of which also were grown in lowa) were analyzed to
determine environmental influence on fatty acid content. The parents of the hybrids and the inbreds were classified in one
of four heterotic groups: Lancaster, Stiff Stalk, non-Lancaster/non-Stiff Stalk, and Other.t-Tests and correlation analyses were performed with statistical significance accepted at a level ofP≤0.05. The findings showed a wide range of fatty acid profiles present in adapted, elite corn breeding materials with ranges
for each fatty acid as follows: palmitic acid, 6.7–16.5%; palmitoleic acid, 0.0–1.2%; stearic acid, 0.7–6.6%; oleic acid,
16.2–43.8%; linoleic acid, 39.5–69.5%; linolenic acid, 0.0–3.1%; and arachidic acid, 0.0–1.0%. Small amounts of myristic acid,
margaric acid, and gadoleic acid also were found. Three lines had total saturates of 9.1% or less. Thirty-six of thet-tests involving hybrids showed significant differences among heterotic groups. There were small but significant correlations
among protein, starch and oil content and the amounts of several fatty acids. Results from the corn grown in France vs. lowa
demonstrated a large environmental effect that overwhelmed the genetic differences among lines. This study shows that for
some attributes, a breeding program involving adapted corn breeding materials might produce the desired oil. Other types of
oil (such as high-oleic) would have to be produced in a different manner, for example, by a breeding program with exotic breeding
materials. 相似文献