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1.
Ratjika Chanamai D. Julian McClements 《Journal of the American Oil Chemists' Society》1998,75(10):1447-1448
The frequency dependence (1–60 MHz) of the ultrasonic attenuation coefficient of canola oil, corn oil, olive oil, peanut oil,
safflower oil, soybean oil, and sunflower oil was measured at 25°C. The attenuation coefficient of all the oils could be described
by the relation: α ∼ Af
n(with A between 6 and 40 × 10−12, and n between 1.74 and 1.86). 相似文献
2.
Conversion of oils to monoglycerides by glycerolysis in supercritical carbon dioxide media 总被引:1,自引:0,他引:1
Feral Temelli Jerry W. King Gary R. List 《Journal of the American Oil Chemists' Society》1996,73(6):699-706
Glycerolysis of soybean oil was conducted in a supercritical carbon dioxide (SC-CO2) atmosphere to produce monoglycerides (MG) in a stirred autoclave at 150–250°C, over a pressure range of 20.7–62.1 MPa, at
glycerol/oil molar ratios between 15–25, and water concentrations of 0–8% (wt% of glycerol). MG, di-, triglyceride, and free
fatty acid (FFA) composition of the reaction mixture as a function of time was analyzed by supercritical fluid chromatography.
Glycerolysis did not occur at 150°C but proceeded to a limited extent at 200°C within 4 h reaction time; however, it did proceed
rapidly at 250°C. At 250°C, MG formation decreased significantly (P<0.05) with pressure and increased with glycerol/oil ratio and water concentration. A maximum MG content of 49.2% was achieved
at 250°C, 20.7 MPa, a glycerol/oil ratio of 25 and 4% water after 4 h. These conditions also resulted in the formation of
14% FFA. Conversions of other oils (peanut, corn, canola, and cottonseed) were also attempted. Soybean and cottonseed oil
yielded the highest and lowest conversion to MG, respectively. Conducting this industrially important reaction in SC-CO2 atmosphere offered numerous advantages, compared to conventional alkalicatalyzed glycerolysis, including elimination of the
alkali catalyst, production of a lighter color and less odor, and ease of separation of the CO2 from the reaction products. 相似文献
3.
Kanit Krisnangkura 《Journal of the American Oil Chemists' Society》1991,68(1):56-58
Equations were developed for the estimation of gross heat of combustion (HG) of triglycerides (TGs) and fatty acid methyl
esters (FAMEs) from their saponification number (SN) and iodine value (IV). HG of TG=1,896,000/SN − 0.6 IV — 1600 and HG of
FAME=618,000/SN − 0.08 IV — 430. When these equations were tested on cottonseed oil, soybean oil, partially hydrogenated soybean
oil, peanut oil, sunflower oil, sunflower oil methyl esters, soybean oil methyl esters and cottonseed oil methyl esters, predicted
HG values agreed well with those reported in the literature. 相似文献
4.
D. F. Andrade J. L. Mazzei C. R. Kaiser L. A. d’Avila 《Journal of the American Oil Chemists' Society》2012,89(4):619-630
In the present work we make assessments of the correlation of equations based on 1H-NMR data for the analysis of FAME in 45 transesterification products with methanol from several vegetable oils (soybean,
corn, sunflower, canola, linseed, cottonseed and jatropha). The products employed in this study were of high and low yield.
A comprehensive approach to the applicability, advantages and limitations of employing NMR expressions is described. A new
expression to determine the degree of unsaturation of combined and free fatty acids was found to be satisfactory when compared
with the classic expression. Estimates of uncertainties for classic equations, which have been used to determine yield and
degree of unsaturation, were proposed in the present work. The results show that either one or both of the expressions for
estimating yields could not be satisfactorily used for products from linseed oil, and also indicate the possibility that products
from cottonseed oil may also be exceptions. Both the equations were found to be satisfactory for the products obtained from
the other oils (soybean, corn, sunflower, canola and jatropha), considering the uncertainties proposed in the present work. 相似文献
5.
Anna-Maija Lampi Afaf Kamal-Eldin 《Journal of the American Oil Chemists' Society》1998,75(12):1699-1703
The antipolymerization effects of α- and γ-tocopherols were compared in model systems composed of purified high-oleic sunflower
triacylglycerols at 180°C. γ-Tocopherol was much more effective as an antipolymerization inhibitor than α-tocopherol, partly
due to lower oxidizability/disappearance. Purified triacylglycerols of sunflower, rapeseed, and high-oleic sunflower oils
were less stable than their nonpurified forms containing tocopherols. Results confirmed that tocopherols per se can act as antipolymerization agents in high-oleic oils at frying temperatures. No synergism was observed when α- and γ-tocopherols
were present together although larger amounts of residuals were left for both tocols. Results suggested that high-oleic/high-γ-tocopherol
oils (such as high-oleic canola and high-oleic soybean oils) may provide better frying oils than high-oleic/high-α-tocopherol
oils (such as high-oleic sunflower oil). 相似文献
6.
P. J. Wan T. W. Hurley J. D. Guy D. L. Berner 《Journal of the American Oil Chemists' Society》1997,74(6):731-738
Color as a fundamental quality of edible oils has been determined primarily by visual comparison methods for many decades.
The automatic colorimeters introduced recently made it possible to replace the manually operated visual color instrument,
which requires experience to master and is often subject to operator variabilities. A previous study with an automatic colorimeter,
Colourscan, to measure the colors of refined and refined bleached cottonseed oils showed good agreement (r
2=0.99) with visual color measurements by means of the Lovibond-AOCS Color Scale. The current work is to establish a broad-scale
correlation between the automated colorimeter and visual color measurements. In this international effort, factory-processed
refined and refined, bleached, deodorized (RBD) canola, corn, cottonseed, peanut, sunflower and soybean oils, as well as refined
palm olein, RBD palm oil, and washed, dried, filtered and deodorized tallow were used. A total of 14 laboratories from the
United States and Canada, and 16 laboratories from 12 countries outside of North America, participated in this collaborative
study. The results of this study, with statistical analyses, are reported. 相似文献
7.
Tocopherols in breeding lines and effects of planting location, fatty acid composition, and temperature during development 总被引:2,自引:4,他引:2
David Dolde Chris Vlahakis Jan Hazebroek 《Journal of the American Oil Chemists' Society》1999,76(3):349-355
As the use of tocopherols as natural antioxidants increases, it is economically and agronomically important to determine the
range, composition, and factors that affect their levels in oilseed crops, a major commercial source. In this study, tocopherols
were quantified from seeds of wheat, sunflower, canola, and soybean. The breeding lines analyzed possessed a broad range of
economically important phenotypic traits such as disease or herbicide resistance, improved yield and agronomic characteristics,
and altered storage oil fatty acid composition. Complete separation of all four native tocopherols was achieved using normal-phase
high-performance liquid chromatography with ultraviolet detection. Total tocopherol concentration among wheat germ oil samples
ranged from 1947 to 4082 μg g−1. Total tocopherol concentration ranges varied from 534 to 1858 μg g−1 in sunflower, 504 to 687 μg g−1 in canola, and 1205 to 2195 μg g−1 among the soybean oils surveyed. Although the composition of tocopherols varied substantially among crops, composition was
stable within each crop. Total tocopherol concentration and the percentage linolenic acid were correlated positively in soybean
oils with modified and unmodified fatty acid compositions. Tocopherol concentration and degree of unsaturation were not correlated
in sunflower or canola seeds with genetically altered fatty acid composition. These findings suggest that breeding for altered
storage oil fatty acid composition did not negatively impact tocopherol concentrations in sunflower and canola as they apparently
did in soybeans. When 12 soybean breeding lines were grown at each of five locations, significant correlations were observed
among planting location, breeding line, tocopherol concentration, and fatty acid composition. Analysis of seeds that matured
under three different controlled temperature regimes suggests that the relationship between tocopherol concentration level
and unsaturated fatty acids in commodity (not genetically modified for fatty acid composition) oil types is due to temperature
effects on the biosynthesis of both compounds. 相似文献
8.
L. J. Malcolmson M. Vaisey-Genser R. Przybylski N. A. M. Eskin 《Journal of the American Oil Chemists' Society》1994,71(4):435-440
Sensory studies on autoxidation of canola oil, stored under several variations of Schaal Oven test conditions, suggest an
induction period of 2–4 d at 60–65°C. Similar induction periods have been observed between canola and sunflower oils, whereas
a longer induction period has been found for soybean oil. Canola oil seems to be more stable to storage in light than cottonseed
and soybean oils but is less stable than sunflower oil. Storage stability of products fried in canola oil is similar to products
fried in soybean oil. Storage stability of canola and cottonseed oils that had been used in the frying of potato chips showed
that canola oil was more prone to autoxidation during storage at 40°C. The presence of light aggravated the oxidative effects
and was similar for both oils. Advances in our knowledge about the shelf life of canola oil would be strengthened by standardization
of Schaal Oven testing conditions and by specifying the testing protocol for photooxidation studies. Methods for training
of panelists and for handling and evaluating oils and fried foods require definition. Rating scales used in the evaluation
of oils need to be evaluated to ensure that reliable and valid measurements are achieved. Further progress is needed in the
identification of chemical indicators that can be used to predict sensory quality of oils.
Presented in part at AOCS Annual Meeting in Toronto, Ontario, Canada, May 1992. 相似文献
9.
Mixing different proportions of high-oleic sunflower oil (HOSO) with polyunsaturated vegetable oils provides a simple method
to prepare more stable edible oils with a wide range of desired fatty acid composition. Oxidative stability of soybean, canola
and corn oils, blended with different proportions of HOSO to lower the respective levels of linolenate and linoleate, was
evaluated at 60°C. Oxidation was determined by two methods: peroxide value and volatiles (hexanal and propanal) by static
headspace capillary gas chromatography. Determination of hexanal and propanal in mixtures of vegetable oils provided a sensitive
index of linoleate and linolenate oxidation, respectively. Our evaluations demonstrated that all-cis oil compositions of improved oxidative stability can be formulated by blening soybean, canola and corn oils with different
proportions of HOSO. On the basis of peroxide values, a partially hydrogenated soybean oil containing 4.5% linolenate was
more stable than the mixture of soybean oil and HOSO containing 4.5% linolenate. However, on the basis of volatile analysis,
mixtures of soybean and HOSO containing 2.0 and 4.5% linolenate were equivalent or better in oxidative stability than the
hydrogenated soybean oil. Mixtures of canola oil and HOSO containing 1 and 2% linolenate had the same or better oxidative
stability than did the hydrogenated canola oil containing 1% linolenate. These studies suggest that we can obviate catalytic
hydrogenation of linolenate-containing vegetable oils by blending with HOSO.
Presented at the AOCS/JOCS joint meeting, Anaheim, CA, April 25–29, 1993. 相似文献
10.
G. R. List T. L. Mounts F. Orthoefer W. E. Neff 《Journal of the American Oil Chemists' Society》1995,72(3):379-382
Liquid vegetable oils (VO), including cottonseed, peanut, soybean, corn, and canola, were randomly interesterified with completely
hydrogenated soybean or cottonseed hardstocks (vegetable oil trisaturate; VOTS) in ratios of four parts VO and one part VOTS.
Analysis of the reaction products by high-performance liquid chromatography showed that at 70°C and vigorous agitation, with
0.5% sodium methoxide catalyst, the reactions were complete after 15 min. Solid-fat index (SFI) measurements made at 50, 70,
80, 92, and 104°F, along with drop melting points, indicated that the interesterified fats possess plasticity curves in the
range of commercial soft tub margarine oils prepared by blending hydrogenated stocks. Shortening basestocks were prepared
by randomly interesterifying palm or soybean oil with VOTS in ratios of 1:1 or 3:1 or 4:1, respectively. Blending of the interesterified
basestocks with additional liquid VO yielded products having SFI curves very similar to commercial all purpose-type shortening
oils made by blending hydrogenated stocks. Other studies show that fluid-type shortening oils can be prepared through blending
of interesterified basestocks with liquid VO. X-ray diffraction studies showed that the desirable β′ crystal structure is
achieved through interesterification and blending.
Presented at AOCS Annual Meeting & Expo, Atlanta, Georgia, May 8–12, 1994. 相似文献
11.
Determination of tocopherols in vegetable oils 总被引:4,自引:0,他引:4
A. P. Carpenter 《Journal of the American Oil Chemists' Society》1979,56(7):668-671
A rapid (ten minute) and selective method for measuring individual tocopherols found in vegetable oils has been developed
using High Performance Liquid Chromatography (HPLC) with ultraviolet absorbance detection. The samples are analyzed directly
following dissolution in the mobile phase. α -and γ-tocopherols are quantitated based upon their peak areas relative to standard
calibration curves. The measurement of β - and δ-tocopherols in the samples is also based upon the calibration data for the
α - and δ-tocopherol standards since the individual β- and δ- standards were unavailable. The data obtained are compared with
the total tocopherol content as found by a standard colorimetric procedure. The results indicate the HPLC method to be more
reliable in the measurement of samples with high α -tocopherol levels. Soybean, safflower, sunflower, cottonseed, corn, peanut
and olive oils have been examined using this method. 相似文献
12.
Aileen Smiles Yukio Kakuda Bruce E. MacDonald 《Journal of the American Oil Chemists' Society》1988,65(7):1151-1155
Six reagents (water, citric acid, phosphoric acid, oxalic acid, acetic anhydride and maleic anhydride) were evaluated for
their effectiveness in degumming three crude vegetable oils (canola, soybean and sunflower). All chemical reagents tested
were found to be significantly more effective than water in removing lecithin material from all three oils except for acetic
anhydride degumming of canola. Citric and phosphoric acids were found to be very effective in reducing phosphorus levels in
canola oil (91 and 93% removal, respectively). For soybean oil, all reagents except water showed excellent degumming ability
by removing 98% phosphorus, while in the case of sunflower oil, maleic anhydride and oxalic acid produced the highest level
of phosphorus removal (95 and 90%, respectively). Both citric acid and acetic anhydride were effective in removing Fe from
all three oils during degumming (84 to 94%), while phosphoric acid showed slightly lower values (73 to 87%).
No significant changes in the phospholipid composition or fatty acid profiles of the phospholipid classes were observed as
a result of degumming with the various chemical reagents. In general, canola phospholipids were lowest in palmitic, stearic
and linoleic acid and contained the highest levels of oleic acid when compared to soybean and sunflower phospholipids. Both
citric and acetic anhydride were found to influence the removal of an unknown glycolipid significantly. Canola lecithin was
shown to contain a greater amount of glycolipids than sunflower and soybean lecithins. 相似文献
13.
Canola oil is not approved for use in infant formula largely because of concerns over possible accumulation of triglyceride
in heart as a result of the small amounts of erucic acid (22∶1n−9) in the oil. Therefore, the concentration and composition
of heart triglyceride were determined in piglets fed from birth for 10 (n=4–6) or 18 (n=6) d with formula containing about 50% energy fat as 100% canola oil (0.5% 22∶1n−9) or 100% soybean oil, or 26% canola oil
or soy oil (blend) with palm, high-oleic sunflower and coconut oil, providing amounts of 16∶0 and 18∶1 closer to milk, or
a mix of soy, high-oleic sunflower and flaxseed oils with C16 and C18 fatty acids similar to canola oil but without 22∶1. Biochemical analysis found no differences in heart triglyceride concentrations
among the groups at 10 or 18 d. Assessment of heart triglycerides using Oil Red O staining in select treatments confirmed
no differences between 10-d-old piglets fed formula with 100% canola oil (n=4), 100% soy oil (n=4), or the soy oil blend (n=2). Levels of 22∶1n−9 in heart triglyceride and phospholipid, however, were higher (P<0.01) in piglets fed 100% canola oil or the canola oil blend, with higher levels found in triglycerides compared with phospholipids.
The modest accumulation of 22∶1n−9 associated with feeding canola oil was not associated with biochemical evidence of heart
triglyceride accumulation at 10 and 18 d. 相似文献
14.
Egg yolk was enriched with α-linolenic acid (18∶3n−3) by feeding laying hens diets containing flax, canola or soybean seeds.
Fertilized eggs were incubated and the fatty acid composition of whole body, liver, plasma, brain and the cholesterol content
of plasma and liver tissue of the hatched chicks were studied. Eggs enriched with 18∶2n−6 fatty acids by feeding hens diets
containing sunflower seeds were used as the controls. Feeding flax enriched (P<0.05) egg yolk and the developing progeny with 18∶3n−3, 20∶5n−3, 22∶5n−3 and 22∶6n−3. Feeding sunflower seeds resulted in
an increase (P<0.05) of 18∶2n−6, 20∶4n−6, 22∶4n−6 and 22∶5n−6. The predominant polyunsaturated fatty acid of the brain was docosahexaenoic
acid (22∶6n−3) which was higher (P<0.05) in the flax and canola fed group. The cholesterol content of the liver tissue was lower (P<0.05) in chicks hatched from hens fed flax seeds. This study indicates that 18∶3n−3 and 18∶2n−6 in the maternal diet are
potent modulators of long-chain polyunsaturated n−3 or n−6 fatty acid and of cholesterol content in the developing progeny. 相似文献
15.
Frank W. Welsh Ross E. Williams Shirley C. Chang Chantel J. Dicaire 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1991,52(2):201-209
Corn oil, peanut oil, sunflower oil, soybean oil, canola oil, olive oil and butter oil were tested as replacements for nonaqueous solvents in the lipase mediated biosynthesis of ethyl butyrate, butyl butyrate, isoamyl butyrate and isoamyl acetate. The most effective oils tested were butter oil, soybean oil, peanut oil and olive oil (yield = 50–60% after 16 h incubation at 25°C) while corn oil was least effective (yield = 38%). Higher yields were obtained, for all ester syntheses, at a reaction temperature of 50°C. Drying agents were shown to have no effect or to inhibit the synthesis. Of the four enzymes tested, Candida cylindracea lipase was the most effective enzyme for ethyl butyrate synthesis. 相似文献
16.
K. Warner C. D. Evans G. R. List H. P. Dupuy J. I. Wadsworth G. E. Goheen 《Journal of the American Oil Chemists' Society》1978,55(2):252-256
Samples of commercially processed soybean, cottonseed, and peanut oils were stored under controlled conditions then evaluated
for flavor by a 20-member trained, experienced oil panel and for pentanal and hexanal contents by direct gas chromatography.
The oils, which contained citric acid and/or antioxidants, were either aged from 0 to 16 days at 60 C or exposed to fluorescent
light for 0 to 16 hr. The simple linear regressions of flavor score with the logarithm of pentanal or hexanal content in aged
soybean oil gave correlation coefficients of −0.96 and −0.90, respectively; for cottonseed oil, −0.60 and −0.85; and for peanut
oil −0.74 and −0.75. Addition of peroxide values to the linear regressions increased the correlation coefficients. Flavor
scores of cottonseed and peanut oil can be predicted from pentanal and hexanal contents, but the technique is slightly more
reliable for soybean oil based on the treatments used for these oils.
Presented at the AOCS Meeting, Chicago, September 1973. 相似文献
17.
Polymerization of vegetable oils and their uses in printing inks 总被引:4,自引:0,他引:4
Ink vehicles were prepared by the polymerization of vegetable oils. By controlling the polymerization conditions, the desired
viscosity, color and molecular weight could be achieved for a variety of vegetable oils with a broad range of iodine values
and fatty acid compositions. The effect of temperature and catalyst on polymerization rates were evaluated, and polymerization
rate constants were calculated. Of the oils tested, the polymerization rate constant of safflower oil was the highest, followed
by soybean, sunflower, cottonseed and canola oils in decreasing order. Use of a catalyst shortened the heating time by about
25–50% or lowered the polymerization temperature requirement by 25–30°C. 相似文献
18.
Amy E. Clough 《Journal of the American Oil Chemists' Society》1992,69(5):456-460
Square-wave voltammetry (SWV) has been applied to the determination of tocopherol concentrations in eight vegetable oils:
canola, corn, olive, peanut, safflower, sesame, soybean, and sunflower. This technique has a lower limit of detection and
somewhat better resolution than differential-pulse voltammetry (DPV) and is significantly faster than both DPV and high-performance
liquid chromatography (HPLC), the technique most often used for tocopherol determinations. The tocopherols are oxidized at
a stationary glassy carbon electrode as its potential is scanned from 0.40 to 1.00 Vvs Ag/AgCl at a rate of 20 mV/s. The currents that arise from these oxidations are directly proportional to the tocopherols’
concentrations. A standard addition method is used to determine the tocopherol contents of the oils listed. Under the conditions
employed, the limit of detection is 10 mg/L tocopherol in oil. 相似文献
19.
Bleaching of alkali-refined vegetable oils with clay minerals 总被引:5,自引:0,他引:5
Keito Boki Moriaki Kubo Tetsuyuki Wada Takamichi Tamura 《Journal of the American Oil Chemists' Society》1992,69(3):232-236
Bleaching efficiencies of bentonites, montmorillonites and sepiolites for alkali-refined rapesseed, soybean, wheatgerm, safflower,
corn, cottonseed and sunflower oils were investigated by a batch method at 110°C. The sepiolites with more acid sites at −5.6
< Ho ≥ −3.0 were the most effective in bleaching of each alkali-refined oil. Surface area and acidity at −5.6>Ho ≥ −3.0 were highly significant with bleaching efficiency. The sepiolites (numbers 2 and 3) were more suitable than standard
activated clay because they were more effective both in retaining tocopherols and in reducing free fatty acids after bleaching. 相似文献
20.
Effects of filtration through activated carbons on peroxide,thiobarbituric acid and carbonyl values of autoxidized soybean oil 总被引:1,自引:0,他引:1
Keito Boki Tetsuyuki Wada Shinsaku Ohno 《Journal of the American Oil Chemists' Society》1991,68(8):561-565
Effects of filtration bleaching on peroxide value (PV), thiobarbituric acid value (TAV) and carbonyl value (CV) of autoxidized
soybean oil were investigated by using twenty-three kinds of activated carbon in order to improve oil quality. From the decreases
in PV, TAV and CV and from the physical and chemical properties of activated carbons, it was suggested that hydroperoxides,
aldehydes and ketones were adsorbed on the acid sites distributed over the surface or within the pores of the activated carbons
while the autoxidized soybean oil flowed through the packed column. The residual tocopherols in autoxidized soybean oil and
treated soybean oil were determined during storage. The decrease in oxidative stability of treated soybean oil seemed to be
caused by elimination ofα-,β-andγ-tocopherols.δ-Tocopherol was chemically more stable thanα-,β- andγ-tocopherols in autoxidized soybean oil. 相似文献