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1.
Endogenous antioxidants and stability of sesame oil as affected by processing and storage 总被引:1,自引:0,他引:1
F. Shahidi R. Amarowicz H. A. Abou-Gharbia A. Adel Y. Shehata 《Journal of the American Oil Chemists' Society》1997,74(2):143-148
The effect of processing of coated and dehulled sesame seeds on the content of endogenous antioxidants, namely sesamin, sesamolin,
and γ-tocopherol in hexane-extracted oils, was studied over 35 d of storage under Schaal oven test conditions at 65°C. Seeds
examined were Egyptian coated (EC) and dehulled (ED) and Sudanese coated (SC) varieties. Processing conditions of raw (RW)
seeds included roasting at 200°C for 20 min (R), steaming at 100°C for 20 min (S), roasting at 200°C for 15 min plus steaming
for 7 min (RS) and microwaving at 2450 MHz for 15 min (M). The sesamin content in fresh oils from EC, ED, and SC raw seeds
was 649, 610, and 580 mg/100 g oil, respectively. Corresponding values for the content of sesamolin in oils tested were 183,
168 and 349 mg/100 g oil, respectively. Meanwhile, the content of γ-tocopherol, the only tocopherol present in the oils, ranged
from 330 to 387 mg/kg sample. The effect of processing on changes in the sesamin content in oils from coated seeds was low
and generally did not exceed 20% of the original values. On the other hand, oils from dehulled seeds underwent a more pronounced
decrease in their sesamin content than the oil from coated seeds after 35 d of storage at 65°C. The corresponding changes
in sesamolin and γ-tocopherol contents were more drastic. The RS treatment, which would be the optimal to prepare sesame oil
with better quality, was found to retain 86, 80 and 60% of the sesamin, sesamolin and γ-tocopherol, respectively, originally
present in the seeds after the storage period. The loss in the content of endogenous antioxidants present in the oils paralleled
an increase in their hexanal content. 相似文献
2.
Ali A. Moazzami Stefanie L. Haese Afaf Kamal‐Eldin 《European Journal of Lipid Science and Technology》2007,109(10):1022-1027
Sesame seed (Sesamum indicum L.) is a rich source of furofuran lignans with a wide range of potential biological activities. The major lignans in sesame seeds are the oil‐soluble sesamin and sesamolin, as well as glucosides of sesaminol and sesamolinol that reside in the defatted sesame flour. Upon refining of sesame oil, acid‐catalyzed transformation of sesamin to episesamin and of sesamolin to epimeric sesaminols takes place, making the profile of refined sesame oils different from that of virgin oils. In this study, the total lignan content of 14 sesame seeds ranged between 405 and 1178 mg/100 g and the total lignan content in 14 different products, including tahini, ranged between 11 and 763 mg/100 g. The content of sesamin and sesamolin in ten commercial virgin and roasted sesame oils was in the range of 444–1601 mg/100 g oil. In five refined sesame oils, sesamin ranged between 118 and 401 mg/100 g seed, episesamin between 12 and 206 mg/100 g seed, and the total contents of sesaminol epimers between 5 and 35 mg/100 g seed, and no sesamolin was found. Thus, there is a great variation in the types and amounts of lignans in sesame seeds, seed products and oils. This knowledge is important for nutritionists working on resolving the connection between diet and health. Since the consumption of sesame seed products is increasing steadily in Europe and USA, it is important to include sesame seed lignans in databases and studies pertinent to the nutritional significance of antioxidants and phytoestrogens. It is also important to differentiate between virgin, roasted and refined sesame oils. 相似文献
3.
Sesame seed is a rich source of dietary lignans 总被引:6,自引:0,他引:6
The variation in the contents of sesamin and sesamolin was studied in oils extracted from 65 samples of sesame seeds (Sesamum indicum L.) from plants with shattering (n=29), semishattering (n=7), and nondehiscent (n=29) capsules. The oil content ranged from 32.5 to 50.6% and was greater in white than black seeds (P<0.001). The sesamin and sesamolin contents in seeds ranged from 7 to 712 mg/100 g (mean±SD, 163±141 mg/100 g) and from 21
to 297 mg/100 g (101±58 mg/100 g), respectively, with no difference between black and white seeds. Thus, there was a wide
variation in the contents of sesamin and sesamolin, which were positively correlated (R
2=0.66, P<0.001). There were negative correlations between the contents of sesamin and the contents of sesaminol (R
2=0.37) and sesamolinol (R
2=0.36) and between the content of sesamolin and those of sesaminol (R
2=0.35) and sesamolinol (R
2=0.46) (P<0.001). Sesame seeds had an average of 0.63% lignans, making them a rich source of dietary lignans. 相似文献
4.
Analysis of tocopherols and phytosterols in vegetable oils by HPLC with evaporative light-scattering detection 总被引:1,自引:5,他引:1
Methods were developed for the separation, detection, and quantification of tocopherols and phytosterols by high-performance
liquid chromatography with an evaporative light-scattering detector. Four tocopherols— α, β, γ and δ—and four phytosterols—campesterol,
β-sitosterol, brassicasterol, and stigmasterol—were analyzed in soybean, sunflower, low-erucic acid rapeseed (LEAR) and corn
oils. The use of an evaporative light-scattering detector, in conjunction with modification of methods from the literature
to prepare and analyze tocopherols and phytosterols by HPLC, showed consistent results between trials and levels of these
minor constituents.
Presented at the Annual American Oil Chemists' Society Meeting, May 3–7, 1989, Cincinnati, OH. 相似文献
5.
Anna-Maija Lampi Leena Kataja Afaf Kamal-Eldin Piironen Vieno 《Journal of the American Oil Chemists' Society》1999,76(6):749-755
Antioxidant properties of 5 to 500 μg/g levels of α-and γ-tocopherols, in the oxidation of rapeseed oil triacylglycerols (RO
TAG), were studied at 40°C in the dark. Each tocopherol alone and in a mixture was studied for its stability in oxidizing
RO TAG. Also the effects of tocopherols on the formation of primary and secondary oxidation products of RO TAG were investigated.
Both tocopherols significantly retarded the oxidation of RO TAG. At low levels (≤50 μg/g), α-tocopherol was more stable and
was a more effective antioxidant than γ-tocopherol. At higher α-tocopherol levels (>100 μg/g), there was a relative increase
in hydroperoxide formation parallel to consumption of α-tocopherol, which was not found with γ-tocopherol. Therefore, γ-tocopherol
was a more effective antioxidant than α-tocopherol at levels above 100 μg/g. As long as there were tocopherols present, the
hydroperoxides were quite stable and no volatile aldehydes were formed. In a mixture, α-tocopherol protected γ-tocopherol
from being oxidized at the addition levels of 5+5 and 10+10 μg/g but no synergism between the tocopherols was found. α-Tocopherol
was less stable in the 500+500 μg/g mixture than when added alone to the RO TAG. No prooxidant activity of either tocopherol
or their mixture was found. 相似文献
6.
Anna-Maija Lampi Anu Hopia Vieno Piironen 《Journal of the American Oil Chemists' Society》1997,74(5):549-555
The effects of minor amounts of γ-tocopherol on the oxidation of natural triacylglycerols (TAG) of rapeseed (RO) and butter
oils (BO) were studied. Four different TAG materials were blended from chromatographically purified TAG that contained 100–25%
of RO TAG. The RO TAG contained from <1 to 43 μg γ-tocopherol per gram of TAG, which corresponded to ≤6% of the total tocopherols
in the original RO. The TAG were held at 40°C in the dark for 4 wk and followed at regular intervals by measurements of hydroperoxide
formation by peroxide values and of secondary product formation by p-anisidine values at regular intervals. In all TAG, minor amounts of γ-tocopherol retarded oxidation. In RO TAG, concentrations
as low as 11 μg/g of γ-tocopherol (1.5% of the total tocopherols in the original RO) were enough to decrease hydroperoxide
and secondary product formation to 46 and 39%, respectively. The effect was even more important in TAG mixtures that contained
BO TAG. There were no significant differences between oxidation of the RO TAG at 24 μg/g, the 75% RO TAG mixture at 11 μg/g,
and the 50% RO TAG mixture at 3 μg/g of γ-tocopherol. Even at these minor levels, γ-tocopherol was a significant antioxidant,
which is important in oxidation studies of purified model systems. 相似文献
7.
J. C. Evans D. R. Kodali P. B. Addis 《Journal of the American Oil Chemists' Society》2002,79(1):47-51
The optimal concentration for tocopherols to inhibit soybean oil oxidation was determined for individual tocopherols (α-,
γ-, and δ-tocopherol) and for the natural soybean oil tocopherol mixture (tocopherol ratio of 1∶13∶5 for α-, γ-, and δ-tocopherol,
respectively). The concentration of the individual tocopherols influenced oil oxidation rates, and the optimal concentrations
were unique for each tocopherol. For example, the optimal concentrations for α-tocopherol and γ-tocopherol were ∼100 and ∼300
ppm, respectively, whereas δ-tocopherol did not exhibit a distinct concentration optimum at the levels studied (P<0.05). The optimal concentration for the natural tocopherol mixture ranged between 340 and 660 ppm tocopherols (P<0.05). The antioxidant activity of the tocopherols diminished when the tocopherol levels exceeded their optimal concentrations.
Above their optimal concentrations, the individual tocopherols and the tocopherol mixture exhibited prooxidation behavior
that was more pronounced with increasing temperature from 40 to 60°C (P<0.05). A comparison of the antioxidant activity of the individual tocopherols at their optimal concentrations revealed that
α-tocopherol (∼100 ppm) was 3–5 times more potent than γ-tocopherol (∼300 ppm) and 16–32 times more potent than δ-tocopherol
(∼1900 ppm). 相似文献
8.
A. Kamal-Eldin G. Yousif L. Å. Appelqvist 《Journal of the American Oil Chemists' Society》1991,68(11):844-847
A new, two-dimensional thin-layer chromatographic system was established to provide good separation of the unsaponifiable
fractions from the seed oils of three wildSesamum species, [S. alatum, Thonn.;S. radiatum, Schum and Thonn.; andS. angustifolium, (Oliv.) Engl.] and of the cultivatedS. indicum, L. The system utilizes silica gel plates and n-hexane/diethyl ether (7:3, v/v) and chloroform/diethyl ether (9:1, v/v) as
mobile phases in the first and second directions, respectively. The system could be used for qualitative studies and as a
preparative technique for subsequent quantitative gas chromatographic separations in chemotaxonomic and related studies onSesamum spp. 相似文献
9.
T. Tashiro Y. Fukuda T. Osawa M. Namiki 《Journal of the American Oil Chemists' Society》1990,67(8):508-511
Oil and mior components of sesamin and sesamolin were studied in 42 strains ofSesamum indicum L. The oil contents of the seed ranged from 43.4 to 58.8% and varied inversely with the percentage of hull (r=−0.804, significant
at the 1% level). The hull percentage was used as a criterion to predict oil content. The percentage of sesamin in the oil
ranged from 0.07 to 0.61% and that of sesamolin from 0.02 to 0.48%. There was a significant positive correlation between the
oil content of the seed and the sesamin content of the oil (r=0.608, significant at the 1% level); no correlation was found
between the oil and sesamolin contents.
The average oil content found for the white-seeded strains was 55.0% and for the black-seeded strains 47.8%, the difference
of 7.2% being significant at the 1% level. The white- and black-seed strains also differed significantly in sesamin content,
but not in sesamolin content. 相似文献
10.
A. Kamal-Eldin L. Å. Appelqvist G. Yousif 《Journal of the American Oil Chemists' Society》1994,71(2):141-147
Different chromatographic methods, thin-layer chromatography (TLC), gas chromatography (GC), gas chromatography/mass spectrometry
(GC/MS) and normal- and reversed-phase high-performance liquid chromatography (HPLC), were compared for their ability to separate
the different lignans present in fourSesamum species,viz., S. indicum Linn.,S. alatum Thonn., S. radiatum Schum & Thonn. andS. angustifolium (Oliv.) Engl. The advantages and limitations of each method are discussed, and a combination of methods is suggested for
qualitative analyses. Two-dimensional TLC was found to be a valuable qualitative technique and one-dimensional TLC is useful
for preparative purposes. GC is a good supplement for qualitative analysis, but it had many limitations as a quantitative
tool—it involves many preparative steps, no suitable internal standard was found to be commercially available and the various
lignans had markedly different response factors. GC/MS is a necessary techniqee to confirm the identity of the lignans present.
HPLC is a one-step technique suitable for quantitative analyses, and is fast and simple because it involves direct injection
of oil solutions. Reversed-phase HPLC was unable to separate sesamolin and sesangolin, but a normal-phase silica column provided
satisfactory separation for these two lignans. 2-Episesalation ofS. alatum, however, did not elute from the normalphase column. Once lignans are identified, a relevant HPLC method can be used for
quantitative analyses. Sesamin was present in large amounts inS. radiatum, in considerable amounts inS. indicum andS. angustifolium, and in small amounts inS. alatum. Sesamolin occurred in considerable amounts inS. indicum andS. angustifolium, but only in small amounts in the other two wild species studied.Sesamum alatum was characterized by high amounts of 2-episesalatin, andS. angustifolium was characterized by high levels of sesangolin. 相似文献
11.
Marjukka M Kinen Afaf Kamal-Eldin Anna-Maija Lampi Anu Hopia 《Journal of the American Oil Chemists' Society》2000,77(8):801-806
The antioxidant effects of α-and γ-tocopherols (at 0, 10, 100, 500, and 1000 ppm) were evaluated in a model system based on
the autoxidation of methyl linoleate in bulk for 4 d at 40°C. Samples were collected every 24 h and analyzed for the 9 cis,trans, 9 trans,trans, 13 cis,trans, and 13 trans,trans isomers of hydroperoxide, hydroxy, and ketodiene oxidation products by high-performance liquid chromatography. Results showed
that both α- and γ-tocopherols are effective hydrogen donors as evidenced by their abilities to inhibit the formation of hydroperoxides,
hydroxy compounds, and ketodienes and the cis,trans to trans,trans isomerization of hydroperoxides. Compared with γ-tocopherol, α-tocopherol was a more efficient antioxidant at very low concentrations
(10 ppm) but a less efficient antioxidant at the high concentrations (100–1000 ppm). This paradoxical behavior is explained
on the basis of differences in ease of hydrogen donation between the two tocopherol homologs. Although α-tocopherol shows
some loss of efficiency with increasing concentration, it is not a prooxidant when compared to the control void of antioxidants. 相似文献
12.
Analysis of the positional distribution of the furanoid fatty acids, 10,13-epoxy-11,12-dimethyloctadeca-10, 12-dienoic acid
(F20) and 12,15-epoxy-13,14-dimethyleicosa-12,14-dienoic acid (F22), in soybean oil (SBO) indicated that they were preferentially
esterified with the primary-OH groups of glycerol molecules. Hydrogenation of SBO reduced the concentrations of F20 and F22
somewhat. During exposure of SBO to daylight, F20 and F22 were completely degraded within two days, whereas linoleic acid
and linolenic acid were not affected. β-Carotene inhibited both the degradation of the furanoid fatty acids and their oxidation
to the odorant 3-methyl-nonane-2,4-dione (MND), which contributes strongly to the light-induced off-flavor of SBO. A model
experiment indicated that two days of light exposure of SBO, followed by filtration through silica gel and further refining,
prevented the formation of MND during subsequent storage of the oil.
Presented at the 86th Annual Meeting of the American Oil Chemists’ Society, San Antonio, Texas, May 7–11, 1995. 相似文献
13.
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
14.
Hydrocarbons produced by γ-radiation of sesame seed were analyzed to determine the relation of irradiation dose to the production
of hydrocarbons and to eventually use them as markers for identifying post-irradiated sesame seed. Hydrocarbons in sesame
seed were determined by a sequential procedure of lipid extraction by hexane, Florisil column chromatography, and gas chromatography.
16:2, 16:3, 17:1, and 17:2 were prominently detected in irradiated sesame seed, 17:2 was detected in seed irradiated at 0.1
kGy or higher, and the others were detected at 0.5 kGy or higher. These hydrocarbons were not detected in unirradiated sesame
seeds that were raw, roasted, whole, ground, or stored. 相似文献
15.
López Antonio Montaño Alfredo Garrido Antonio 《Journal of the American Oil Chemists' Society》2005,82(2):129-133
A survey of vitamin E levels in a wide variety of olive-based foodstuffs was conducted. Vitamin E was determined by normal-phase
HPLC. The only form of vitamin E found in all commercial presentations of table olives was α-tocopherol, with an average content
of 3.1 mg/100 g edible portion. A very low content (<0.4 mg/100 g edible portion) of γ-tocopherol was found in most of the
samples analyzed. The main sources of variation of vitamin E were olive cultivars and commercial presentations. Processing
type (Spanish style green olives, directly brined olives, ripe olives) had a limited influence. Irrespective of the elaboration
style, the Gordal cultivar was the poorest with respect to the vitamin E content. On the other hand, all commercial presentations
based on the Hojiblanca cultivar had high contents of vitamin E. The results of this study may be used by the industry for
requirements of nutritional labeling or by nutritionists to estimate vitamin E intakes in diets that include table olives. 相似文献
16.
During national and regional health surveys, done from 1984–1995 in Germany, consumption data for all drugs used by the participants—approximately
18,000 persons—in the last 7 d before the examination were monitored with a detailed drug-usage questionnaire. The groups
examined are representative for the national and regional German inhabitant population aged 25–69 yr. In serum samples of
subsamples of the study participants, all tocopherols were measured by isocratic high-performance liquid chromatography (Si
60 column, fluorescence detection). Consumption data for tocopherol-containing drugs showed that up to 5% of females and up
to 3% of males of the study population used those drugs. During the study period, the serum content of α-tocopherol (mean
values ± SD) rose from 7.5 ± 2.6 mg/L serum to 11.8 ± 2.8 mg/L serum for nonusers and from 11.9 ± 4.3 mg/L serum to 15.3 ±
4.9 mg/L serum in tocopherol-drug users. Throughout all studies, it could be shown that β- and γ-tocopherol were heavily reduced
in those persons taking daily doses ≥50 mg α-tocopherol. The reduction of the two tocopherols is dose-dependent and especially
pronounced in females using high-dose α-tocopherol drugs. Owing to the emerging evidence of the physiological importance concerning
the balance of the different tocopherols in biological systems, the possible benefits of using natural tocopherol mixtures
from plant origin instead of pure RRR-α-tocopherol, gained from permethylation procedures, as vitamin supplements in human nutrition should be considered. 相似文献
17.
Temperature effects on tocopherol composition in soybeans with genetically improved oil quality 总被引:7,自引:5,他引:2
G. O. Almonor G. P. Fenner R. F. Wilson 《Journal of the American Oil Chemists' Society》1998,75(5):591-596
Tocopherol, a natural antioxidant, typically accounts for a small percentage of soybean (Glycine max L. Merr.) oil. Alleles that govern the expression of polyunsaturated fatty acids in soybean germplasm are influenced by temperature.
However, little is known about the environmental influences on tocopherol expression. The objective of this study was to assess
the influence of temperature on tocopherol composition in soybean germplasm that exhibit homozygous recessive and dominant
alleles that govern the predominant ω-6 and ω-3 desaturases. The control cv. Dare and three low-18:3 genotypes (N78-2245,
PI-123440, N85-2176) were grown under controlled-temperature environments during reproductive growth. Analysis of crude oil
composition at various stages of seed development revealed a strong negative correlation between total tocopherol content
and growth temperature. The relative strength of this correlation was greater in the germplasm that exhibited homozygous alleles
governing the ω-6 desaturase than those governing the ω-3 desaturase. The decline in total tocopherol with reduced temperature
was attributed predominantly to loss of γ-tocopherol. However, γ-tocopherol concentration also was directly related to 18:3
concentration in all genotypes. Thus, low-18:3 oils contained both a lower content and a lower concentration of γ-tocopherol.
Although the biochemical basis for this observation is unknown, the antioxidant capacity of γ-tocopherol appeared to be directly
associated with changes in oil quality that were mediated more by genetic than by environmental influences on 18:3 concentration.
Another aspect of this work showed that low-18:3 soybean varieties should be expected to contain more α-tocopherol, especially
when grown under normal commercial production environments. This condition should be regarded as another beneficial aspect
of plant breeding approaches to the improvement of soybean oil quality. 相似文献
18.
《分离科学与技术》2012,47(9):1321-1330
Seventeen resins were evaluated by their adsorption capacities from two solvent systems, ethanol aqueous solution and surfactant emulsifiable solution, prepared from Schisandra chinensis. The adsorption of lignans from surfactant emulsifiable solution on LS-305, XAD-16, HPD-100, and XAD-4 as a function of contact time, initial adsorbate concentration, and temperature was investigated by using batch experiments. LS-305 and XAD-16 exhibited higher lignans adsorption capacity than HPD-100 and XAD-4. The adsorption kinetics and Freundlich isotherm model of lignans on the four resins were well described by a pseudo-second-order and Freundlich isotherm models, respectively. The adsorption of lignans on the resins was spontaneous. 相似文献
19.
An electronic nose was used for the detection of maize oil adulteration in camellia seed oil and sesame oil. The results of multivariate analysis of variance showed that the sensor signals of different kinds of oil are significantly different from each other. Principal component analysis (PCA) cannot be used to discriminate the adulteration of camellia seed oil, but can be used in the discrimination of adulteration in sesame oil. Linear discriminant analysis (LDA) is more effective than PCA and can be used in adulteration discrimination for both camellia seed oil and sesame oil. In order to check the discriminative power of LDA, canonical discriminant analysis was performed as well. Acceptable results were also obtained: The accuracy of prediction was 83.6% for camellia seed oil and 94.5% for sesame oil. The artificial neural network (ANN) model was used to detect the percentage of adulteration in camellia seed oil and sesame oil. The results showed that, based on ANN as its pattern recognition technique, the electronic nose cannot predict the percentage of adulteration in camellia seed oil, but can be used in the quantitative determination of adulteration in sesame oil. 相似文献
20.
M. Baldioli M. Servili G. Perretti G. F. Montedoro 《Journal of the American Oil Chemists' Society》1996,73(11):1589-1593
The antioxidant effects of hydrophilic phenols and tocopherols on the oxidative stability in virgin olive oils and in purified
olive oil have been evaluated. Total hydrophilic phenols and the oleosidic forms of 3,4-dihydroxyphenolethanol (3,4-DHPEA)
were correlated (r=0.97) with the oxidative stability of virgin olive oil. On the contrary, tocopherols showed low correlation (r=0.05). Purified olive oil with the dialdehydic form of elenolic acid linked to 3,4-DHPEA, an isomer of oleuropeine aglycon,
and 3,4-DHPEA had good oxidative stability. A synergistic effect was observed in the mixture of 3,4-DHPEA and its oleosidic
forms with α-tocopherol in purified olive oil by the Rancimat method at 120°C. 相似文献