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1.
Dihydro-vitamin K1 was recently identified as a dietary form of vitamin K produced during the hydrogenation of vitamin K1-rich vegetable oils. Dihydro-vitamin K1 is absorbed, with measurable levels in human plasma following dietary intake. To determine the primary food sources of dihydro-vitamin
K1 in the American diet, 261 foods from the U.S. Food and Drug Administration's (FDA) Total Diet Study (TDS) were analyzed by
high-performance liquid chromatography. Of these foods, 36 contained dihydro-vitamin K1. Fast-food items that were otherwise poor sources of vitamin K1, such as french fries and fried chicken, contained appreciable amounts of dihydro-vitamin K1 (36 and 18 μg/100 g, respectively). These nutrient values were then applied to the FDA TDS consumption model to determine
average dietary intake of dihydro-vitamin K1 in 14 age-gender groups. With the exception of infants, all age-gender groups had estimated mean daily dihydro-vitamin K1 intakes of 12–24 μg, compared to mean daily vitamin K1 intakes of 24–86 μg. The vitamin K1 and dihydro-vitamin K1 intakes were summed, and the dietary contribution of dihydro-vitamin K1 was expressed as a percentage of total vitamin K intake. Children reported the highest intakes of dihydro-vitamin K1 (30% of total vitamin K intake), followed by a progressive decrease in percentage contribution with age. There are currently
no data on the relative bioavailability of dihydro-vitamin K1 but, given its abundance in the American diet, this hydrogenated form of vitamin K warrants further investigation. 相似文献
2.
K. Warner W. E. Neff G. R. List Peter Pintauro 《Journal of the American Oil Chemists' Society》2000,77(10):1113-1118
Soybean oils were hydrogenated either electrochemically with Pd at 50 or 60°C to iodine values (IV) of 104 and 90 or commercially
with Ni to iodine values of 94 and 68. To determine the composition and sensory characteristics, oils were evaluated for triacylglycerol
(TAG) structure, stereospecific analysis, fatty acids, solid fat index, and odor attributes in room odor tests. Trans fatty acid contents were 17 and 43.5% for the commercially hydrogenated oils and 9.8% for both electrochemically hydrogenated
products. Compositional analysis of the oils showed higher levels of stearic and linoleic acids in the electrochemically hydrogenated
oils and higher oleic acid levels in the chemically hydrogenated products. TAG analysis confirmed these findings. Monoenes
were the predominant species in the commercial oils, whereas dienes and saturates were predominant components of the electrochemically
processed samples. Free fatty acid values and peroxide values were low in electrochemically hydrogenated oils, indicating
no problems from hydrolysis or oxidation during hydrogenation. The solid fat index profile of a 15∶85 blend of electrochemically
hydrogenated soybean oil (IV=90) with a liquid soybean oil was equivalent to that of a commercial stick margarine. In room
odor evaluations of oils heated at frying temperature (190°C), chemically hydrogenated soybean oils showed strong intensities
of an undesirable characteristic hydrogenation aroma (waxy, sweet, flowery, fruity, and/or crayon-like odors). However, the
electrochemically hydrogenated samples showed only weak intensities of this odor, indicating that the hydrogenation aroma/flavor
would be much less detectable in foods fried in the electrochemically hydrogenated soybean oils than in chemically hydrogenated
soybean oils. Electrochemical hydrogenation produced deodorized oils with lower levels of trans fatty acids, compositions suitable for margarines, and lower intensity levels of off-odors, including hydrogenation aroma,
when heated to 190°C than did commercially hydrogenated oil. 相似文献
3.
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
4.
Diets rich in polyunsaturated fatty acids (PUFA) are well known to suppress hepatic lipogenic enzymes compared to fat-free
diets or diets rich in saturated fatty acids. However, the mechanism underlying suppression of lipogenic enzymes is not quite
clear. The present study was undertaken to investigate whether lipid peroxidation products are involved in suppression of
lipogenic enzymes. Therefore, an experiment with growing male rats assigned to six groups over a period of 40 d was carried
out. Rats received semisynthetic diets containing 9.5% coconut oil and 0.5% fresh soybean oil (coconut oil diet, peroxide
value 5.1 meq O2/kg oil), 10% fresh soybean oil (fresh soybean oil diet, peroxide value 0.5 meq O2/kg oil), or 10% thermally treated soybean oil (oxidized soybean oil diet, peroxide value 74 meq O2/kg oil). To modify the antioxidant state of the rats, we varied the vitamin E supply (11 and 511 mg α-tocopherol equivalents
per kg of diet) according to a bi-factorial design. Food intake and body weight gain were not influenced by dietary fat and
vitamin E supply. Activities of hepatic lipogenic enzymes were markedly influenced by the dietary fat. Feeding either fresh
or oxidized soybean oil diets markedly reduced activities of fatty acid synthase, (FAS), acetyl CoA-carboxylase, (AcCX), glucose-6-phosphate
dehydrogenase, (G6PDH), 6-phosphogluconate dehydrogenase, and ATP citrate lyase (ACL) relative to feeding the coconut oil
diet. Moreover, feeding oxidized soybean oil slightly, but significantly, lowered activities of FAS, AcCX, and ACL compared
to feeding fresh soybean oil. Activities of hepatic lipogenic enzymes were reflected by concentrations of triglycerides in
liver and plasma. Rats fed the coconut oil diet had markedly higher triglyceride concentrations in liver and plasma than rats
consuming fresh or oxidized soybean oil diets, and rats fed oxidized soybean oil had lower concentrations than rats fed fresh
soybean oil. The vitamin E supply of the rats markedly influenced concentrations of thiobarbituric acid-reactive substances
in liver, but it did not influence activities of hepatic lipogenic enzymes. Because the vitamin E supply had no effect, and
ingestion of an oxidized oil had only a minor effect, on activities of hepatic lipogenic enzymes, it is strongly suggested
that neither exogenous nor endogenous lipid peroxidation products play a significant role in the suppression of hepatic lipogenic
enzymes by diets rich in PUFA. Therefore, we assumed that dietary PUFA themselves are involved in regulatio of hepatic lipogenic
enzymes. Nevertheless, the study shows that ingestion of oxidized oils, regardless of the vitamin E supply, also affects hepatic
lipogenesis, and hence influences triglyceride levels in liver and plasma. 相似文献
5.
R. B. Alfin-Slater R. B. Morris L. Aftergood D. Melnick 《Journal of the American Oil Chemists' Society》1969,46(12):657-661
In studies conducted on male and female rats and involving evaluation of growth, reproductive and lactation performances and
of lipid peroxidation, no evidence could be found for the need for added vitamin E (a-tocopherol) over and above that naturally present as tocopherols in the vegetable oils investigated. These oils are in common
usage in industry, i.e., liquid nonhydrogenated cottonseed oil, a lightly hydrogenated cottonseed oil and a hydrogenated soybean
oil shortening. The ratio of polyunsaturates to total tocopherol in the test oils varied from 640:1 to 9:1. Even those oils
obtained from a commercial frying operation after a steady state had been attained contained sufficient vitamin E to meet
dietary requirements. Results of in vitro peroxide hemolysis tests conducted on the red blood cells of the test animals did
not correlate well with biological performance. 相似文献
6.
E. N. Frankel 《Journal of the American Oil Chemists' Society》1970,47(1):11-14
Chromium carbonyl complex catalysts were used to selectively hydrogenate polyunsaturates in vegetable oils into products retaining
90% to 95%cis configuration and their liquid properties. The product from soybean oil contained 42–69% monoene, 10–40% diene and 0–4% triene.
The product from safflower oil contained 73–82% monoene and 8–17% diene. About 45–55% of the double bonds in monoenes from
hydrogenated soybean oil remained in the C9 position, and the rest was distributed between C10, C11, and C12. Preliminary oxidative and flavor stability evaluations showed that these hydrogenated soybean oils compared favorably with
a commercial sample of hydrogenated-winterized soybean oil. Liquid fatty acids prepared by saponification of hydrogenated
soybean and safflower oils (IV 90–100) had analyses about the same as those of commercial oleic acid.
Presented before the Division of Agricultural and Food Chemistry, 156th American Chemical Society National Meeting, Atlantic
City, N.J., September 1968. 相似文献
7.
James W. Peterson Karry L. Muzzey David Haytowitz Jacob Exler Linda Lemar Sarah L. Booth 《Journal of the American Oil Chemists' Society》2002,79(7):641-646
Assessment of vitamin K (VK) dietary intakes has been limited by the incompleteness of VK food composition data for the U.S.
food supply, particularly for VK-rich oils. The phylloquinone (VK-1) and 2′,3′-dihydrophylloquinone (dK) concentrations of
margarines and spreads (n=43), butter (n=4), shortening (n=4), vegetable oils (n=6), and salad dressings (n=24) were determined by RP-HPLC with fluorescence detection. Each sample represented a composite of units or packages obtained
from 12 or 24 outlets, which were geographically representative of the U.S. food supply. Butter, which is derived from animal
fat sources, had less VK-1 compared to vegetable oil sources. The VK-1 and dK of the margarines and spreads increased with
fat content and the degree of hydrogenation, respectively. In some margarines or spreads and in all shortenings, the dK concentrations
were higher than the corresponding VK-1 concentrations. As the fat content of salad dressings increased, the VK-1 concentrations
also increased. Fat-free foods had <1 μg/100 g of either form of the vitamin. No dK was detected in the salad dressings or
oils tested. Some margarines, spreads, and salad dressings may be significant sources of vitamin K in the U.S. food supply. 相似文献
8.
L. Hernqvist O. Leissner B. Petersson 《European Journal of Lipid Science and Technology》1987,89(5):190-193
A new type of low erucic acid rapeseed oil containing high amount (11%) of palmitic acid (C16-LOBRA) was studied, both in labscale and in pilot-plant equipment. The polymorphic behaviour of fat blends and margarine emulsions consisting of C16-LOBRA, LOBRA and soybean oil and their hydrogenated fats were examined. The results clearly show the potential in the hydrogenated C16-LOBRA. The time before the stable ß-form is developed is much longer for the hydrogenated C16-LOBRA compared with the hydrogenated LOBRA and in fact similar to a hydrogenated soybean oil. The hydrogenated C16-LOBRA is therefore well suited to be used in e.g. margarine systems. 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.
Casimir C. Akoh 《Journal of the American Oil Chemists' Society》1994,71(2):211-216
Oxidative Stability Index (OSI) of carbohydrate fatty acid polyesters, fat substitutes and vegetable oils were measured with
the Omnion Oxidative Stability Instrument according to the new AOCS Standard Method Cd 12 B-92 (The Official Methods and Recommended Practices of the American Oil Chemists' Society, edited by D. Firestone, AOCS, Champaign, 1991). The stability of crude and refined, bleached and deodorized (RBD) vegetable
oils (soybean, hydrogenated soybean and peanut) were determined at 110°C. In addition, OSI times for sucrose polyesters of
soybean oil, butterfat, oleate:stearate and methyl glucoside polyester of soybean oil were determined in the absence and in
the presence of 0.02 wt% antioxidants, [Tenox TBHQ (tertiary butylhydroquinone, Tenox GT-2 (from Eastman Chemical Products
(Kingsport, TN); and vitamin E (from BASF, Wyandotte, MI)], and the results were compared with those of vegetable oils. Crude
oils were most stable (20.4–25.9 h), followed by RBD oils (9.3–10.4 h) for soybean and peanut oils, respectively, and fat
substitutes (3.8–6.8 h). Overall, Tenox TBHQ was the best antioxidant for improving the oxidative stability of both vegetable
oils and fat substitutes. The sucrose polyester made with oleic and stearic acid was more stable than fat substitutes containing
more polyunsaturated fatty acids, such as those from soybean oil, or from short-chain fatty acids, such as from butterfat.
Antioxidants enhanced the stability of RBD oils (222% increase) and synthetic fat substitutes (421–424% increase) more than
that of crude oils (33% increase). The shapes of the induction curves, not the actual OSI times for fat substitutes and vegetable
oils, were similar and sharply defined. 相似文献
11.
Male Sprague Dawley rats were fed semipurified diets containing 20% fat for 15 weeks. The dietary fats were corn oil, soybean
oil, palm oil, palm olein and palm stearin. No differences in the body and organ weights of rats fed the various diets were
evident. Plasma cholesterol levels of rats fed soybean oil were significantly lower than those of rats fed corn oil, palm
oil, palm olein or palm stearin. Significant differences between the plasma cholesterol content of rats fed corn oil and rats
fed the three palm oils were not evident. HDL cholesterol was raised in rats fed the three palm oil diets compared to the
rats fed either corn oil or soybean oil. The cholesterol-phospholipid molar ratio of rat platelets was not influenced by the
dietary fat type. The formation of 6-keto-PGF1α was significantly enhanced in palm oil-fed rats compared to all other dietary treatments. Fatty acid compositional changes
in the plasma cholesterol esters and plasma triglycerides were diet regulated with significant differences between rats fed
the polyunsaturated corn and soybean oil compared to the three palm oils. 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.
J. B. Meltzer E. N. Frankel T. R. Bessler E. G. Perkins 《Journal of the American Oil Chemists' Society》1981,58(7):A779-A784
Cyclic monomers derived from the intramolecular condensation of the C18 polyunsaturated fatty acids have been reported to elicit toxic responses when fed to laboratory animals at low dietary levels.
This study was undertaken to quantitate the cyclic monomers formed by thermal oxidation induced during deep fat frying to
assess the potential toxicity of commonly used vegetable oils. Two separate experiments were designed to study the effects
of unsaturation and both intermittent and continuous heating on cyclic monomer formation. Both lightly hydrogenated soybean
oil (iodine value [IV]=107) and refined, bleached and deodorized soybean oil were studied. The heated oil sustained substantial
chemical and physical alterations, as indicated by IV decreases from 10–15 units, increases in free fatty acids of 5–10-fold
and in noneluted material of 18–21%. Selected samples were completely hydrogenated and analyzed for cyclic monomers by gas
chromatography. Under chromatographic conditions sufficiently sensitive to detect a cyclic monomer standard at less than 0.5%
by weight, no cyclic monomers were detected in any of the heated oil samples. However, after concentration by low temperature
crystallization of the hydrogenated samples to remove a major portion of the saturated components interfering in cyclic monomer
resolution, about 0.3–0.6% cyclic acids, as well as 0.4–0.9% polar materials, were detected in the heated soybean oils. Components
appearing in the gas chromatogram with the same retention time as those in a cyclic monomer standard were further identified
by gas chromatography-mass spectrometry as disubstituted cyclic C-18 acids. 相似文献
14.
Bente Kirkhus Amandine Lamglait Ivar Storrø Gjermund Vogt Elisabeth Olsen Frank Lundby Håkon Standal 《Journal of the American Oil Chemists' Society》2015,92(2):215-223
The thermal stability of liquid margarine and vegetable oils was investigated by measuring the oxidative stability index (OSI) at temperatures ranging from 90 to 180 °C, whereas total polar compounds (TPC) and tocopherols (vitamin E) were measured during heating at 180 °C in frying trays. Results showed that the OSI of liquid margarine was in the same range as the OSI of vegetable oils at lower temperatures, but at 160 and 180 °C, liquid margarine had significantly higher thermal stability, close to that observed for hard margarine and butter. The increased stability was confirmed by lower levels of TPC and a smaller relative reduction in vitamin E content during heating. Variations between different vegetable oils could partly be explained by differences in degree of saturation and level of vitamin E, with high oleic sunflower oil being the most stable oil at all temperatures. The water in liquid margarine vaporized within 1.5 min at 160 °C, and it is hypothesized that volatile pro‐oxidants are removed with the water, inducing a delay in deterioration. The results indicate a role for water in preventing lipid oxidation and decomposition in fat emulsion products at 160–180 °C, suggesting that liquid margarine, low in saturated fat, may be the healthier and preferable alternative for pan‐frying compared to other liquid vegetable oils. 相似文献
15.
Food technological aspects on the use of rape-seed oil and otherCruciferae seed oils as salad oils, in margarine, shortenings and some other foods are briefly reviewed. It is concluded that these
oils in hydrogenated or nonhydrogenated form may compete favorably with other vegetable oils and animal fats.
One of nine papers published from the Symposium, “Cruciferous Oilseeds,” ISF-AOCS World Congress, Chicago, September 1970. 相似文献
16.
Peter J. H. Jones 《Lipids》1994,29(7):491-495
The objective of this study was to examine whether whole body oxidation rates of dietary linoleic, α-linolenic and oleic acids
differ when the acids are provided in identical quantities. Male rats were fed for 10 wk a 15% fat (w/w) diet containing equal
amounts of linoleic, α-linolenic and oleic acids (22.7, 23.0 and 23.2% of total fatty acids, respectively). At week 10, after
overnight fasting, rats were intragastrically administered 20 μCi of either [1-14C]-labelled linoleic, α-linolenic or oleic acid in a 200-μL bolus of oil containing equal quantities of each fatty acid. The
appearance of14CO2 in expired air was then monitored hourly for 12h for each animal. A preliminary study had shown that growth and food consumption
patterns in animals consuming the oil containing equal quantities of each of the fatty acids paralleled the patterns of animals
that were self-selecting among separate diets, each of which contained one of the component oils. The appearance of14C, expressed as percent dose administered, peaked at 2–3 h post-dose for14C-labelled linoleic (5.28±0.37%/h), α-linolenic (6.92±0.51%/h) and oleic (5.98±0.44%/h) acids. Statistically these values
were not significantly different. Cumulative14CO2 excretion rates over 12 h were also similar for linoleic (27.2±0.9%), α-linolenic (26.8±1.2%) and oleic (25.9±1.2%) acids.
The results suggest that the rat's capacity to oxidize 18-carbon unsaturated fatty acids is not affected by fatty acid unsaturation
when these fatty acids are provided at equal dietary levels. 相似文献
17.
Ratnayake WM Plouffe L Hollywood R L'Abbé MR Hidiroglou N Sarwar G Mueller R 《Lipids》2000,35(4):409-420
In recent studies, the life span of stroke-prone spontaneously hypertensive (SHRSP) rats was altered by a variety of dietary
fats. It was relatively shorter in rats fed canola oil as the sole source of fat. The present study was performed to find
out whether the fatty acid profile and the high content of sulfur compounds in canola oil could modulate the life span of
SHRSP rats. SHRSP rats (47 d old, n=23/group) were matched by body weight and systolic blood pressure and fed semipurified diets containing 10% canola oil, high-palmitic
canola oil, low-sulfur canola oil, soybean oil, high-oleic safflower oil, a fat blend that mimicked the fatty acid composition
of canola oil, or a fat blend high in saturated fatty acids. A 1% sodium chloride solution was used as drinking water to induce
hypertension. After consuming the diets for 37 d, five rats from each dietary group were killed for collection of blood and
tissue samples for biochemical analysis. The 18 remaining animals from each group were used for determining their life span.
The mean survival time of SHRSP rats fed canola oil (87.4±4.0 d) was not significantly different (P>0.05) from those fed low-sulfur canola oil (89.7±8.5 d), suggesting that content of sulfur in canola oil has no effect on
the life span of SHRSP rats. The SHRSP rats fed the noncanola oil-based diets lived longer (mean survival time difference
was 6–13 d, P<0.05) than those fed canola and low-sulfur canola oils. No marked differences in the survival times were observed among the
noncanola oil-based groups. The fatty acid composition of the dietary oils and of red blood cells and liver of SHRSP rats
killed after 37 d of treatment showed no relationship with the survival times. These results suggest that the fatty acid profile
of vegetable oils plays no important role on the life span of SHRSP rat. However, phytosterols in the dietary oils and in
liver and brain were inversely correlated with the mean survival times, indicating that the differential effects of vegetable
oils might be ascribed, at least partly, to their different phytosterol contents. 相似文献
18.
This study was designed to determine whether incorporation of γ-tocotrienol or α-tocopherol in an atherogenic diet would reduce
the concentration of plasma cholesterol, triglycerides and fatty acid peroxides, and attenuate platelet aggregability in rats.
For six weeks, male Wistar rats (n=90) were fed AIN76A semisynthetic test diets containing cholesterol (2% by weight), providing
fat as partially hydrogenated soybean oil (20% by weight), menhaden oil (20%) or corn oil (2%). Feeding the ration with menhaden
oil resulted in the highest concentrations of plasma cholesterol, low and very low density lipoprotein cholesterol, triglycerides,
thiobarbituric acid reactive substances and fatty acid hydroperoxides. Consumption of the ration containing γ-tocotrienol
(50 μ/kg) and α-tocopherol (500 mg/kg) for six weeks led to decreased plasma lipid concentrations. Plasma cholesterol, low
and very low density lipoprotein cholesterol, and triglycerides each decreased significantly (P<0.001). Plasma thiobarbituric acid reactive substances decreased significantly (P<0.01), as did the fatty acid hydroperoxides (P<0.05), when the diet contained both chromanols. Supplementation with γ-tocotrienol resulted in similar, though quantitatively
smaller, decrements in these plasma values. Plasma α-tocopherol concentrations were lowest in rats fed menhaden oil without
either chromanol. Though plasma α-tocopherol did not rise with γ-tocotrienol supplementation at 50 mg/kg, γ-tocotrienol at
100 mg/kg of ration spared plasma α-tocopherol, which rose from 0.60±0.2 to 1.34±0.4 mg/dL (P<0.05). The highest concentration of α-tocopherol was measured in plasma of animals fed a ration supplemented with α-tocopherol
at 500 mg/kg. In response to added collagen, the partially hydrogenated soybean oil diet without supplementary cholesterol
led to reduced platelet aggregation as compared with the cholesterol-supplemented diet. However, γ-tocotrienol at a level
of 50 mg/kg in the cholesterol-supplemented diet did not significantly reduce platelet aggregation. Platelets from animals
fed the menhaden oil diet released less adenosine triphosphate than the ones from any other diet group. The data suggest that
the combination of γ-tocotrienol and α-tocopherol, as present in palm oil distillates, deserves further evaluation as a potential
hypolipemic agent in hyperlipemic humans at atherogenic risk. 相似文献
19.
The examination of samples of various commer-cially available vegetable oils (olive oil, sunflower oil, thistle oil, linseed
oil, plant germ oil, etc.) and of various samples of margarine for the presence of vola-tile N-nitroso-compounds yielded the
following results. By means of the above mentioned procedure (gas liquid chromatography — AFID gas liquid chromatography —
TEA), N-nitrosodimethylamine (NDMA) was found to be present in 21 of 61 dif-ferent samples of vegetable oil, in concentrations
ranging from < 1 μg/kg to 23 μg/kg. 18 samples con-tained N-nitrosodiethylamine (NDEA) in concentra-tions varying between
< 1μg/kg and 27.8 μg/kg. 37 out of 107 different samples of margarine were shown to contain N-nitroso compounds. N-nitroso-dimethylamine
was found to be present in 15 samples. The range of concentrations determined was between < 1 μg/kg and 5.8 μg/kg. 33 samples
con-tained N-nitrosodiethylamine in concentrations varying between < 1 μg/kg and 7.5 μg/kg. 相似文献
20.
Luciano Hocevar Vitória R. B. Soares Fábio S. Oliveira Maria Graças A. Korn Leonardo S. G. Teixeira 《Journal of the American Oil Chemists' Society》2012,89(5):781-786
Mid-infrared spectroscopy, in association with multivariate chemometric techniques, was employed for pattern recognition and
the determination of the composition of waste frying oils (WFO); data are presented in terms of the percentage of soybean
oil, palm oil and hydrogenated vegetable fat in frying oil blends. Principal component analysis (PCA) was performed using
spectral data (3,000–600 cm−1) to discriminate between the samples containing 100% soybean oil, 100% palm oil, 100% hydrogenated vegetable fat groups and
their blends. Additionally, the results indicated that partial least squares (PLS) models based on mid-infrared spectra were
suitable as practical analytical methods for predicting the oil contents in WFO blends. PLS models were validated by a representative
prediction set, and the root mean square errors of prediction (RMSEP) were 2.8, 4.7 and 5.5% for palm oil, soybean oil and
hydrogenated vegetable fat, respectively. The proposed methodology can be very useful for the rapid and low cost determination
of waste frying oil composition while also aiding in decisions regarding the management of oil pretreatment and production
routes for biodiesel production. 相似文献