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1.
Minor constituents of vegetable oils during industrial processing 总被引:6,自引:10,他引:6
R. Ap. Ferrari E. Schulte W. Esteves L. Brühl K. D. Mukherjee 《Journal of the American Oil Chemists' Society》1996,73(5):587-592
We report the effects of individual steps of industrial refining, carried out in Brazil, on the alteration of selected minor
constituents of oils, such as corn, soybean, and rapeseed oils. Total sterols, determined by capillary gas chromatography
(GC), decreased by 18–36% in the fully refined oils, compared with the crude oils. The total steradienes, dehydration products
of sterols, were determinedvia a simple clean-up on a short silica gel column, followed by high-performance liquid chromatography (HPLC) with ultraviolet
detection. The level of steradienes, normally not present in crude oils, increased after each refining step, especially after
deodorization. Thus, the content of steradienes increased after deodorization by about 15- to 20-fold in corn and soybean
oils, and by about 2-fold in rapeseed oil. The total steryl esters were also determinedvia clean-up on a short silica gel column, followed by HPLC with evaporative light scattering mass detection. A minor decrease
in the level of steryl esters was observed after complete refining. The individual tocopherols and tocotrienols were determined
by HPLC with a fluorescence detector. The level of total tocopherols and tocotrienols decreased by about 2-fold after complete
refining of corn oil and by about 1.5-fold in soybean and rapeseed oils. In all three cases, maximum reduction of tocopherols
was observed after the deodorization step. The level of polymeric glycerides, determinedvia clean-up on a short silica gel column followed by size-exclusion HPLC, increased to some extent (0.4–1%) during refining.
The level oftrans fatty acids, determined by capillary GC, also increased to a substantial extent (1–4%) after refining.
Part of doctoral thesis of Roseli Ap. Ferrari to be submitted to Faculdade de Engenharia de Alimentos, Universidade de Campinas,
Campinas, Brazil. 相似文献
2.
Male Wistar rats were fed semipurified diets containing 20% fat for 25 weeks. Ten different oils or oil blends were employed,
including rapeseed oils, simulated rapeseed-type oils, and modified rapeseed-type oils. Safflower, soybean, and hydrogenated
coconut oils served as control oils. Histopathological examination of the cardiac tissue was conducted at the end of the study
and an incidence-severity rating assigned to the lesions induced by each fat. Oils containing high levels of erucic acid (26–30%)
induced the most severe cardiac necrosis, irrespective of the source of erucic acid (rapeseed oil or nasturtium oil). Increasing
the linoleic: linolenic acid ratio of the high erucic oils to that of soybean oil failed to reduce necrosis, but the absence
of linolenic acid from a high erucic acid oil blend resulted in a markedly reduced lesion incidence-severity rating, comparable
to those obtained for low erucic acid rapessed oil and soybean oil which were similar. Lowest lesion incidence was obtained
with safflower oil and hydrogenated coconut oil. We have postulated that linolenic acid plays a role in the etiology of cardiac
necrosis observed when rats are fed diets containing low erucic acid rapeseed oils. 相似文献
3.
G. R. List C. D. Evans K. Warner R. E. Beal W. F. Kwolek L. T. Black K. J. Moulton 《Journal of the American Oil Chemists' Society》1977,54(1):8-14
Various processing steps were explored in an at-tempt to improve the quality of oil from field- and storage-damaged soybeans.
A crude soybean oil (5.7% free fatty acid) commercially extracted from damaged soybeans was degummed in the laboratory with
different reagents: water, phosphoric acid, and acetic anhydride. Two alkali strengths, each at 0.1 and 0.5% excess, were
used to refine each degummed oil. After vacuum bleaching (0.5% activated earth) and deodorization (210 C, 3 hr), these oils
were un-acceptable as salad oils. A flavor score of 6.0 or higher characterizes a satisfactory oil. Scores of water and phosphoric
acid degummed oils ranged from 4.5 to 5.1, while acetic anhydride degummed oils aver-aged 5.6. Flavor evaluations of (phosphoric
acid de-gummed) single- and double-refined oils (210 C deodorization) showed that the latter were signifi-cantly better. Flavor
scores increased from 5.0 to about 6.0. To study the effects of deodorization tem-perature, the crude commercial oil was alkali-refined,
water-washed and bleached with 0.5% activated earth, but the degumming step was omitted. Flavor evalua-tion of oil deodorized
at 210, 230, and 260 C showed that each temperature increment raised flavor scores significantly. Further evaluations of specially
proc-essed oils (water, phosphoric acid, and acetic anhy-dride degummed oils given single and double refinings and deodorized
at 260 C) showed that deodorization temperature is the most important factor affecting the initial quality of oil from damaged
beans. Flavor evaluations showed that hydrogenation and hydro-genation-winterization treatments produced oils of high initial
quality, but with poorer keeping proper-ties than oils from normal beans. No evidence was found implicating nonhydratable
phosphatides in the oil flavor problem. Iron had a deleterious effect in oils not treated with citric acid during deodorization.
Presented at AOCS Meeting, Philadelphia, September 1974. 相似文献
4.
The liver oil of deep‐sea dogfish, Centrophorus squamosus, was extracted by different physical methods and refined by sequential processes of degumming, neutralization, decolorization, and deodorization. Phosphoric acid effectively eliminated the mucilaginous substances in crude oil to result in triglycerides with permissible contents of peroxides, unesterified fatty acids, volatile compounds, thiobarbituric acid reactive species, and total oxidation values. A synergistic combination of activated charcoal and Fuller's earth could effectively bleach the crude deep‐sea dogfish liver oil (CDLO) for greater clarity and acceptable color characteristics. The adverse odors in the crude oil were eliminated by acetic acid treatment and vacuum deodorization. This study shows that the multistep refining process of CDLO significantly enhances the composition of C20–22 n‐3 polyunsaturated fatty acids, with the removal of the components responsible for the undesirable physicochemical characteristics. 相似文献
5.
植物甾醇是功能性食品添加剂,大豆植物油脱臭馏出物,有大量的粗植物甾醇的副产物。采用石油醚洗涤乙醇重结晶精制的生产工艺,使用EDTA作为金属络合剂去除金属离子,用高性能的活性炭和活性白土去除苯并芘,从而精制高品质植物甾醇。 相似文献
6.
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
7.
Friedrich Schne Jan Fritsche Jürgen Bargholz Matthias Leiterer Gerhard Jahreis Bertrand Matthus 《European Journal of Lipid Science and Technology》1998,100(12):539-545
Changes of rapeseed and linseed oil during processing During processing of crude oil in a large oil mill, three samples each of rapeseed and linseed were investigated at each processing stage, i.e. press oil, solvent-extracted oil, mixed oil, and degummed/caustic refined oil. In the case of rapeseed also bleached and desodorized oils (230°C; 3.0 mbar for 2 h) were investigated. Rapeseed and linseed oil showing the typical major fatty acids contained less than 1% trans-isomeric fatty acids (trans fatty acids = TFA). Linseed oil had a similar TFA-concentration as rapeseed oil, and the concentrations did not change during the processing stages up to degummed/caustic refined oil, and were also unchanged in the bleached rapeseed oil. Desodorization of rapeseed oil, however, trebled the TFA concentration to 0.58%. The detected tocopherol patterns were typical of rapeseed and linseed oils. There was no difference between mixed oil and degummed/caustic refined oil in the total concentration of tocopherols. Neither had bleaching any effect. Rapeseed oil desodorization diminished total tocopherol concentration by 12% from 740 mg/kg to 650 mg/kg. Due to degumming/caustic refining the phosphorus concentration of both oils decreased to less than a tenth compared to mixed oil. Other elements determined in degummed/caustic refined rapeseed oil were not detectable (manganese < 0.02 mg/kg, iron < 0.4 mg/kg, copper < 0.02 mg/kg, lead < 10 μg/kg) or only as traces zink 0.1 mg/kg, cadmium 2 μg/kg). In linseed oil, which initially showed a higher trace compounds concentration, a significant decrease was found by degumming/caustic refining. Iron could not be detected. There were traces of zinc, manganese, copper, lead, and cadmium. There was no difference between the acid values of rapeseed and linseed crude oil. Acid value decreased drastically already during the degumming/caustic refining stage. The crude linseed oils had a higher peroxide value, anisidine value and diene value than the corresponding crude rapeseed oils. With peroxide values of ≤ 0.1 mEq O2/kg found in almost all investigated rapeseed oils, no effect of refining could be detected. The anisidine value showed an increase after bleaching. Desodorization trebled the diene value. 相似文献
8.
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
9.
Mykola Zajcew 《Journal of the American Oil Chemists' Society》1956,33(7):306-308
Summary Experiments have been made on coconut oil from pure endosperm, pure testa, and normal mixtures of the two. These experiments
have shown that the spread in iodine value between refined coconut oil and the fatty acids found on the corresponding soapstock
are greater than can be accounted for by the proportion of testa oil present in extracted whole crude oils. Furthermore the
iodine value of the free fatty acid fraction of pure endosperm oils was found to be higher than that of the combined fatty
acids in the same oils by an amount which varied inversely as the degree of hydrolysis which had occurred in the oil. From
this it appears that preferential hydrolysis plays an important part in the production of coconut oil soapstock having higher
iodine values than those of the corresponding refined oils.
Attention is also called to some European publications which deal with this question and to the possibility that molds may
be involved through their ability to decompose short chain acids to ketones. 相似文献
10.
H. A. Liebing 《European Journal of Lipid Science and Technology》1970,72(8):640-650
Distillative Deacidification of Fats and Oils Based on the general principles of steam distillation, a method and diagrams for calculating the consumption of stripping steam in the distillative deacidification of various types of fats and oils are given. With the example of distillative deacidification of palm oil, it is shown as to how the minimum consumption of stripping steam is obtained in a two-step process. Subsequently, the corresponding determinations for palm kernel, coconut, peanut and rapeseed oils are shown. The operational scheme of a continuous plant for distillative deacidification and deodorization as well as photos of the fittings of the distilling cylinder are also included. 相似文献
11.
Xiaojun Liu Shengmin Zhou Yuanrong Jiang Xuebing Xu 《Journal of the American Oil Chemists' Society》2021,98(4):475-483
Trans fatty acids (TFA) have been shown to be associated with various health disorders. Due to thermal stress, one major source of dietary TFA is high-temperature deodorization of vegetable oils. In this study, precision minimal deodorization was proposed to obtain healthier “zero-TFA” vegetable oils (TFA ≤0.3%). By optimizing temperatures for different deodorizers, dual columns with dual temperatures (DCDT) deodorizers were proposed, transformed, and industrially implemented among dozens of plants. The deodorization temperatures were optimized and customized, respectively, for four kinds of vegetable oil (soybean oil and rapeseed oil: tray column 205 °C and packed column 225 °C, maize oil and sunflower seed oil: tray column 210 °C and packed column 230 °C). Industrial trials showed that all four kinds of oils can achieve “zero-TFA” by DCDT deodorization at the customized mild temperatures, and meanwhile oil physicochemical qualities and shelf-life stabilities were compared with corresponding conventional refining oils. The initial free fatty acid and color were a little higher than that of conventional refining oils, but no significant differences were shown in change trends of these physicochemical indexes during the shelf life, which indicated a good and stable oil quality of “zero-TFA” oils for future industrial productions and sales. 相似文献
12.
Edible oils such as coconut, groundnut, hydrogenated vegetable, linseed, mustard, olive, palm, refined vegetable, rice bran,
safflower, sesame, soybean, and sunflower were analyzed for the presence of light and heavy polycyclic aromatic hydrocarbon
(PAH) residues using liquid-liquid extraction, cleanup on a silica gel column, and resolution and determination by HPLC using
a fluorescence detector. Ten PAH viz. acenaphthene, anthracene, benzo(a)pyrene, benzo(e)pyrene, benz(ghi)perylene, chrysene,
coronene, cyclopenta(def)phenanthrene, phenanthrene, and pyrene were monitored. Analysis of 296 oil samples showed that 88.5%
(262) samples were contaminated with different PAH. Of 262 contaminated edible oil samples, 66.4% of the samples showed PAH
content of more than the 25 μg/kg recommended by the German Society for Fat Science. The total PAH content was highest in
virgin olive oil (624 μg/kg) and lowest in refined vegetable oils (40.2 μg/kg). The maximum content (265 μg/kg) of heavy PAH
was found in olive oil and the minimum (4.6 μg/kg) in rice bran oil. Phenanthrene was present in 58.3% of the oil samples
analyzed, followed by anthracene (53%). Among the heavy PAH, benzo(e)pyrene was observed in 31.2% of the samples followed
by benzo(a)pyrene (25.5%). The intake of PAH was highest through olive oil (20.8 μg/day) followed by soybean oil (5.0 μg/day)
and lowest through refined vegetable oil (1.3 μg/day). Based on these monitoring studies, international and national guidelines
for permissible levels of PAH can be prepared so as to restrict the intake of these toxic contaminants. 相似文献
13.
Chee Beng Yeoh Chiew Let Chong 《European Journal of Lipid Science and Technology》2009,111(6):593-598
Acephate, methamidophos and monocrotophos are insecticides used in oil palm plantations for the control of bagworms and leaf‐eating caterpillars. The main purpose of this study was to determine whether the physical refining process at laboratory scale, which simulated the manufacturing process, could remove the residues of these three insecticides in crude palm oil, in the unlikely event that crude palm oil were contaminated with these organophosphorus insecticides. A series of crude palm oil samples spiked with low (0.1 µg/g) and high (1.0 µg/g) levels of these insecticides were subjected to a laboratory‐scale physical oil refining process. Oil samples drawn at various stages of the refining process, namely, degumming, bleaching and deodorization, were analyzed using an in‐house analytical method. The results obtained from these experiments suggest that the physical refining process is capable of effectively removing residual insecticides from crude palm oil. The final product of crude palm oil refining, the refined, bleached and deodorized palm oil, was found to have no detectable levels of acephate, methamidophos and monocrotophos. 相似文献
14.
Frank E. Sullivan 《Journal of the American Oil Chemists' Society》1976,53(6):358-360
Steam refining of fatty oils to reduce the partially high free fatty acid content of certain crude oils before conventional
refining has been practiced in Europe for many years. Intensive laboratory testing indicated that crude palm oil could be
pretreated to remove trace metals and certain heat resistant organic compounds. This pretreated oil could then be steam refined
and simultaneously steam deodorized to produce a high quality finished edible oil. Analytical data on crude and finished oil
quality and operating yields are presented to illustrate the steam refining/deodorization process. Laboratory results obtained
by steam refining a variety of other oils also are presented. 相似文献
15.
Jií molík Walter Schwarz Zdenk Svoboda Jan Pokorný Zuzana Rblov Marek Doleal Helena Valentov 《European Journal of Lipid Science and Technology》2000,102(1):15-22
The physical refining of soybean oil was introduced as an energy saving and environmentally friendly procedure alternative to the traditional alkali refining, and the process was successfully applied to other vegetable oils. We had compared the two procedures in industrial refining under conditions, which enable a clear comparison. In nine plant‐scale experiments, crude rapeseed oil, taken from the same tank of crude oil, was processed on the same day both by alkali refining and by physical refining. Quality changes (free fatty acids, peroxide value, conjugated fatty acids, polar lipids, minor constituents) were determined, and also their stability against oxidation (Rancimat and Schaal Oven Test), and the fatty acid composition. In refined oils, the sensory acceptabilities and the sensory profiles were assayed. Finally deodorized oils, produced by the two methods, did not appreciably differ in their sensory characteristics and chemical composition, excepting slightly higher concentration of isomeric polyunsaturated fatty acids in physically refined oils. During storage for one year in commercial packagings at 15 °C, oxidative and sensory changes were negligible. 相似文献
16.
G. R. List J. W. King J. H. Johnson K. Warner T. L. Mounts 《Journal of the American Oil Chemists' Society》1993,70(5):473-476
A hexane-extracted crude soybean oil was degummed in a reactor by counter-currently contacting the oil with supercritical
CO2 at 55 MPa at 70°C. The phosphorus content of the crude oil was reduced from 620 ppm to less than 5 ppm. Degummed feedstocks
were fed (without further processing,i.e., bleaching) directly to a batch physical refining step consisting of simultaneous deacidification/deodorization (1 h @ 260°C
and 1–3 mm Hg) with and without 100 ppm citric acid. Flavor and oxidative stability of the oils was evaluated on freshly deodorized
oils both after accelerated storage at 60°C and after exposure to fluorescent light at 7500 lux. Supercritical CO2-processed oils were compared with a commercially refined/bleached soybean oil that was deodorized under the same conditions.
Flavor evaluations made on noncitrated oils showed that uncomplexed iron lowered initial flavor scores of both the unaged
commercial control and the CO2-processed oils. Oils treated with .01% (100 ppm) citric acid had an initial flavor score about 1 unit higher and were more
stable in accelerated storage tests than their uncitrated counterparts. Supercritical CO2-processed oil had equivalent flavor scores, both initially and after 60°C aging and light exposure as compared to the control
soybean oil. Results showed that bleaching with absorbent clays may be eliminated by the supercritical CO2 counter-current processing step because considerable heat bleaching was observed during deacidification/deodorization. Colors
of salad oils produced under above conditions typically ran 3Y 0.7R. 相似文献
17.
Summary Analyses and comparisons of a number of representative samples have shown that acidulated coconut oil soapstock may have an
iodine value as much as 100% greater than that of the corresponding refined oil without any contamination being involved.
Exactly what the spread between any given soapstock and oil will be apparently depends on the free fatty acid content of the
original crude oil and the relative efficiency of the refining process. It was found that, for coconut soapstocks produced
by standard laboratory refining tests, the relation between free fatty acid content and iodine value spread can be represented
by the formula I.V. Spread=9.5–759 FFA. The efficiency of the refining process affects results insofar as it reduces the entrainment
of neutral oil. Removing all of the neutral oil from four laboratory-produced soapstocks prior to acidulation raised the iodine
value approximately two units in all cases.
The practical significance of these results is obvious. A refiner processing high grade crude coconut oil of 9.5, iodine value
by a highly efficient refining procedure cannot be expected to produce an acidulated soapstock of less than about 18.0 in
iodine value. With higher free fatty acid crude oil and less efficient refining procedures lower iodine values are possible,
but since soapstock is of minor economic value compared to refined oil, the trend will always be toward better grade crude
oils and more efficient refining processes. 相似文献
18.
T. L. Mounts C. D. Evans H. J. Dutton J. C. Cowan 《Journal of the American Oil Chemists' Society》1969,46(9):482-484
A14C-labeled high molecular weight hydrocarbon and an insecticidal compound were added as minor constituents in soybean oil samples.
Liquid scintillation counting was used to assay the radioactivity of the oil preceding and after laboratory simulations of
commercial processing procedures (bleaching and deodorization). Radiochemical techniques were found to be highly sensitive
and quantitative and detection was unaffected by chemical modification or decomposition of the parent compound. Labeled (14C) benzo(a)pyrene was retained primarily by the oil during extraction, filtering, solvent stripping, deodorization and treatment with
AOCS bleaching earths. Treatment of the oil with activated charcoal effected removal of this hydrocarbon. Bleaching was ineffective
in removing added14C-endrin from the oil but a deodorization using specific conditions of temperature (250 C), time (2 hr), and pressure (4.5
mm) removed this constituent.
Presented at the AOCS Meeting, Washington, D.C., March 1967. 相似文献
19.
Refining high-free fatty acid wheat germ oil 总被引:5,自引:5,他引:0
Wheat germ oil was refined using conventional degumming, neutralization, bleaching, and continuous tray deodorization, and
the effects of processing conditions on oil quality were determined. The crude wheat germ oil contained 1,428 ppm phosphorus,
15.7% free fatty acid (FFA), and 2,682 ppm total tocopherol, and had a peroxide value (PV) of 20 meq/kg. Degumming did not
appreciably reduce the phosphorus content, whereas neutralization was effective in removing phospholipid. Total tocopherol
content did not significantly change during degumming, neutralization, and bleaching. A factorial experimental design of three
deodorization tempeatures and three residence times (oil flow rates) was used to determine quality changes during deodorization.
High temperatures and long residence times in deodorization produced oils with less FFA, PV, and red color. Deodorization
at temperatures up to 250°C for up to 9 min did not significantly reduce tocopherol content, but, at 290°C for 30-min residence
time, the tocopherol content was significantly reduced. Good-quality wheat germ oil was produced after modifying standard
oil refining procedures. 相似文献
20.
Effects of processing steps on the contents of minor compounds and oxidation of soybean oil 总被引:4,自引:0,他引:4
The processes of degumming, alkali refining, bleaching and deodorization removed 99.8% phospholipids, 90.7% iron, 100% chlorophyll,
97.3% free fatty acids and 31.8% tocopherols from crude soybean oil. The correlation coefficient between the removals of phosphorus
and iron in soybean oil during processing was r = 0.99. The relative ratios of α-, β -, γ- and δ-tocopherols in crude oil,
degummed oil, refined oil, bleached oil and deodorized soybean oil were almost constant, γ- and δ -tocopherols represented
more than 94% of tocopherols in soybean oil. The order of oxidation stability of oil is crude > deodorized > degummed > refined
> bleached oil. 相似文献