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2.
通过考察催化剂用量、反应温度及反应时间、氧化剂等因素对环氧葵花籽油产率的影响,确定了较适宜的反应条件.在此反应条件下产品产率大于90%.考察了环氧化葵花籽油含量对环氧树脂/环氧葵花籽油共混物冲击强度的影响.结果表明,当环氧化葵花籽油的质量分数为30%时,共混物的冲击强度比纯环氧树脂提高了60%. 相似文献
3.
Wax composition of sunflower seed oils 总被引:1,自引:3,他引:1
Amalia A. Carelli Lorna M. Frizzera Pedro R. Forbito Guillermo H. Crapiste 《Journal of the American Oil Chemists' Society》2002,79(8):763-768
Waxes are natural components of sunflower oils, consisting mainly of esters of FA with fatty alcohols, that are partially
removed in the winterization process during oil refining. The wax composition of sunflower seed as well as the influence of
processing on the oil wax concentration was studied using capillary GLC. Sunflower oils obtained by solvent extraction from
whole seed, dehulled seed, and seed hulls were analyzed and compared with commercial crude and refined oils. The main components
of crude sunflower oil waxes were esters having carbon atom numbers between 36 and 48, with a high concentration in the C40−C42 fraction. Extracted oils showed higher concentrations of waxes than those obtained by pressing, especially in the higher
M.W. fraction, but the wax content was not affected significantly by water degumming. The hull contribution to the sunflower
oil wax content was higher than 40 wt%, resulting in 75 wt % in the crystallized fraction. The oil wax content could be reduced
appreciably by hexane washing or partial dehulling of the seed. Waxes in dewaxed and refined sunflower oils were mainly constituted
by esters containing fewer than 42 carbon atoms, indicating that these were mostly soluble and remained in the oil after processing. 相似文献
4.
Tocopherols are natural antioxidants that increase the stability of fat-containing foods and perform important biological
activities. Significant variations (389 to 1873 μg g oil−1) in the total tocopherol concentration of sunflower seed oil have been reported. The main objectives of this work were to
determine the influence of intercepted photosynthetically active radiation on tocopherol concentration during seed filling
and to establish and validate relationships between tocopherol concentration in oil and other quality variables of the seed.
Seven sunflower hybrids were grown under good water and nutritional conditions in two similar experiments carried out in two
contrasting environments. Treatments were applied to modify the amount of radiation intercepted per plant during seed filling
in order to obtain a range in oil yield per plant and its components. Greater per plant intercepted radiation decreased the
tocopherol concentration in oil. Tocopherol concentration decreased when oil weight per seed increased. Tocopherol concentration
stabilized for oil weight per seed higher than 23 mg oil seed−1. This exponential relationship accounted for 73% of the variability in tocopherol concentration (507 to 1203 μg g oil−1) despite differences in hull type, locations, hybrids, and radiation treatments. The proposed relationship acceptably predicted
independent results. Crop management techniques could lead to seeds with greater concentrations of tocopherols. 相似文献
5.
A. V. Tsiadi E. Stavrides A. Handa-Corrigan 《Journal of the American Oil Chemists' Society》2001,78(4):381-385
High-temperature steam deodorization of sunflower oil results in the formation of unwanted by-products, such as trans isomers and polymers, and partial destruction of vitamins. There is an urgent need to develop a process that replaces steam with an inert gas such as nitrogen. The use of nitrogen bubble sparging at low temperatures has recently been reported as a technique to strip volatiles from edible oils. In this study, a hypothesis was proposed that nitrogen bubbles sparged at temperatures of 25 to 150°C are able to remove odoriferous, surface-active, or volatile contaminants from shallow pools of sunflower oil. Analysis of the composition of sunflower oil that had been sparged at 3 mbar pressure showed that both the odor and peroxide content of the oil were considerably reduced to values that are commercially acceptable. Odor improvement occurred at temperatures between 100 and 150°C, while the peroxide content reduction was achieved at a temperature of 150°C. There were no significant improvements in the free fatty acid concentration or color. 相似文献
6.
Stereospecific analysis of TAG from a sunflower seed oil of Tunisian origin was performed. The TAG were first fractionated
according to chain length and degree of unsaturation by RP-HPLC. The four major diacid- and triacid-TAG fractions were palmitoyldilinoleoyl-glycerol,
dioleoyllinoleoylglycerol, oleoyldilinoleoylglycerol, and palmitoyloleoyl-linoleoyl-glycerol, amounting to 7.2, 16.6, 29.5,
and 12 mol%, respectively. The TAG of the four fractions were individually submitted to stereospecific analysis, using a Grignard-based
partial deacylation, separation of sn-1,2(2,3)-DAG from sn-1,3-DAG by boric acid-impregnated silica gel TLC plates, conversion of the sn-1,2(2,3)-DAG to their 3,5-dinitrophenylurethane (DNPU) derivatives, fractionation of DNPU derivatives by RP-HPLC, resolution
of the DNPU-DAG by HPLC on a chiral column, transmethylation of each sn-DNPU-DAG fraction, and analysis of the resulting FAME by GC. The data obtained were used to determine the triacyl-sn-glycerol composition of the main TAG of the oil. Fifteen triacyl-sn-glycerols were identified and quantified, representing, along with the monoacid-TAG, trilinoleoylglycerol and trioleoylglycerol,
more than 90% of the total oil TAG. The two major triacyl-sn-glycerols were trilinoleoyl-glycerol and 1-linoleoyl-2-linoleoyl-3-oleoyl-glycerol (18.6 and 18.5% of the total, respectively).
Results clearly identified linoleic acid as the major FA at the sn-2 position, whereas oleic and palmitic acids were the major FA at the sn-3 position. The sn-1 position was occupied to nearly the same extent by linoleic and oleic acids, and to a greater extent by palmitic acid,
which was practically absent at the sn-2 position. 相似文献
7.
The influence of carotenoids and tocopherols on the stability of safflower seed oil during heat-catalyzed oxidation 总被引:2,自引:2,他引:0
L. K. Henry G. L. Catignani S. J. Schwartz 《Journal of the American Oil Chemists' Society》1998,75(10):1399-1402
The stability and antioxidant effects of carotenoids and tocopherols in safflower seed oil were evaluated under thermal (75°C)
and oxidative conditions and the oxidative stability index (OSI) determined. The antioxidant capability of butylated hydroxytoluene
(BHT) was also compared with that of β-carotene in a model system. Lycopene and β-carotene (1 to 2000 ppm) were heated (75°C)
and exposed to air (2.5 psi) in an oxidative stability instrument. β-Carotene had no antioxidant effect at concentrations
below 500 ppm, because it did not alter the induction time. Lycopene increased the induction time only slightly at low concentrations.
However, at concentrations greater than 500 ppm, both β-carotene and lycopene acted as prooxidants, significantly decreasing
the induction period. At the highest concentration, 2000 ppm, lycopene was more prooxidative than β-carotene. α- and γ-Tocopherol
(concentration, 1000 ppm) delayed the induction time by 16 and 26 h, respectively. There was no cooperative interaction between
α-tocopherol and β-carotene in delaying the onset of oxidation. Furthermore, BHT was significantly more antioxidative than
β-carotene. Thus, under thermal and oxidative conditions, β-carotene could not delay the onset of oxidation. The tocopherols
and BHT were effective in suppressing the onset of oxidation, as determined by the oxidative stability measurement. 相似文献
8.
Characteristics of tea seed oil in comparison with sunflower and olive oils and its effect as a natural antioxidant 总被引:5,自引:0,他引:5
A comparison of iodine values showed that the degree of saturation of tea seed oil (Lahjan variety) was intermediate between
the oils of sunflowerseed (Fars variety) and olive (Gilezeytoon variety), and the saponification values of these three oils
were similar. Tea seed oil consisted of 56% oleic acid (C18∶1), 22% linoleic acid (C18∶2), 0.3% linolenic acid (C18∶3), and
therefore, on the basis of oleic acid, occupied a place between sunflower and olive oil. In studies at 63°C, the shelf life
of tea seed oil was higher than that of sunflower oil and similar to olive oil. Tea seed oil was found to have a natural antioxidant
effect, and it enhanced the shelf life of sunflower oil at a 5% level. In this study, tea seed oil was found to be a stable
oil, to have suitable nutritional properties (high-oleic, medium-linoleic, and lowlinolenic acid contents), and to be useful
in human foods. 相似文献
9.
Feiyun Yang Bao Zhang Baiting Chen Nafei Yang Ruigang Wang Xiujuan Zhang Guojing Li 《Journal of the American Oil Chemists' Society》2022,99(3):203-213
As important oil crops in Inner Mongolia, sunflower, and flaxseed had distinct lipid profiles in seeds. As an emerging cash crop, Hibiscus manihot L. has strong potential market competitiveness. In this study, the lipidome, fatty acid composition and quality characteristics of flaxseed, H. manihot L., and sunflower seed oils were analyzed and compared. A total of 270 distinct lipids were identified and analyzed with an emerging detection approach—lipidomics, which illustrated the tremendous difference among the samples. triacylglycerol, diacylglycerol and polar lipids were the most abundant lipids in all samples. H. manihot L. seeds contained higher saturated and monounsaturated fatty acids and lower polyunsaturated fatty acids. H. manihot L. seed oil had the longest oxidative stability index time, high content of vitamin E and total phenolics, while flaxseed oil embodied the lowest oxidative stability. The peroxide value and acid value of the three oils were within the allowable range of Chinese national standards. 相似文献
10.
J. Sineiro H. Domínguez M. J. Núñez J. M. Lema 《Journal of the American Oil Chemists' Society》1998,75(6):753-754
Oil extraction by ethanol from partially defatted prepressed sunflower seeds in pulsed and nonpulsed extractors was compared. The oil yield was increased by 8.7% after short extraction periods (up to 6.06 residence times) with a pulsing flow, which was probably due to reduction in the axial dispersion that induces a greater concentration gradient between the miscella surrounding the solid and the bulk miscella. 相似文献
11.
In this study, the effect of ultrasound-assisted extraction (UAE) on oil yield and content of functional food ingredients of hulled and non-hulled sunflower is discussed and compared with conventional extraction methods. The optimum extraction parameters for UAE were as follows: n-hexane as extracting solvent, average particle size 250 ± 12 µm, extraction time 2 h, solid-to-solvent ratio 1:12, ultrasound frequency 24 kHz and temperature 50°C. Furthermore, the chromatograph showed that sunflower oil extracted by the UAE was rich in α-Linolenic acid (ω-3). In addition, a marginal reduction in peroxide values and tocopherols were determined. 相似文献
12.
Isothermal crystallization of waxes was studied by using an optical setup. The induction time of crystallization was assessed as a function of wax concentration. The relationship was found to be a decreasing exponential curve. The wax content of some of the solutions prepared in the laboratory was determined by calculating the crystallization induction time. The values obtained were compared to those from different methods (cold test, microscopic, and turbidimetric methods). The results obtained with the optical setup method are similar to those obtained with other methods for concentrations greater than 100 ppm. An analysis of variance test was used to verify the authenticity of the values obtained with the optical method. Results showed that the method used to determine wax concentration, the concentration of the sample, and the relationship between both parameters do not affect significantly the values of percentage relative errors (P<0.05) obtained for concentrations greater than 100 ppm. Values obtained for wax content within the range 0–100 ppm could not be compared since the microscopic and turbidimetric methods are not sensitive enough, unlike the optical setup, to detect wax amounts in such low concentration. 相似文献
13.
Comparison of the composition and properties of canola and sunflower oil sediments with canola seed hull lipids 总被引:1,自引:0,他引:1
H. Liu R. Przybylski K. Dawson N. A. M. Eskin C. G. Biliaderis 《Journal of the American Oil Chemists' Society》1996,73(4):493-498
The phase transition behavior and chemical composition of sediments from Canadian and Australian canola oils, as well as from
sunflower oil, were studied by differential scanning calorimetry, X-ray diffraction, polarized-light microscopy, and chromatographic
techniques. Australian canola sediment was similar to Canadian canola sediment in both melting and crystallization behaviors
and chemical composition. Compared to canola sediment, sunflower sediment underwent phase transformation (melting and crystallization)
at lower temperatures, and the enthalpies associated with the phase changes were greater. The X-ray diffraction patterns for
these materials were similar, indicating identical crystalline structures. Sunflower sediment contained mainly wax esters
(99%), while canola sediment contained about 72–74% of waxes. Moreover, sunflower sediment consisted of shorter-chainlength
fatty acids and alcohols than canola sediment. A hexane-insoluble fraction from Canadian canola hull lipids had fatty acid
and alcohol profiles and X-ray diffraction pattern similar to the corresponding oil sediment. 相似文献
14.
Quantitative determination of phospholipids in sunflower oil 总被引:4,自引:0,他引:4
Amalia A. Carelli Marta I. V. Brevedan Guillermo H. Crapiste 《Journal of the American Oil Chemists' Society》1997,74(5):511-514
Phospholipids from sunflower oil samples were enriched by using solid-phase extraction (SPE) cartridges and subsequently separated
and analyzed by high-performance liquid chromatography (HPLC) with an ultraviolet detector. The recovery of individual phospholipids
at different total concentrations in model oils and the repeatability of the method were investigated. The results demonstrated
the utility of SPE-HPLC for quantitative analysis of phospholipids in sunflower oil and the effectiveness for concentrating,
separating, identifying, and quantitating phospholipids in samples with phosphatide contents as low as 0.1%. Samples of sunflower
oil at different stages of processing were analyzed, and phospholipid profiles in hexane-extracted oil, hot-pressed oil, and
water-degummed oils were compared. 相似文献
15.
Antonio Romero Carmen Cuesta Francisco J. Sánchez-Muniz 《Journal of the American Oil Chemists' Society》1998,75(2):161-167
Frying stability of sunflower oil (SO) with 23% oleic acid and 61% linoleic acid, and of high-oleic acid sunflower oil (HOSO)
with 74% oleic acid and 13% linoleic acid was studied during 20 discontinuous deep-fat fryings of various frozen foods, with
or without frequent replenishment of the used oil with fresh oil. Alterations of both oils were measured by column, gas-liquid
and high-performance size-exclusion chromatography. Total polar content and compounds, related to thermoxidative changes,
and diacylglycerides, related to hydrolytic changes, increased in all oils during frying but reached higher levels in SO than
in HOSO. Nevertheless, the increased levels of diacylglycerides observed may result from the frozen potatoes prefried in palm
oil. Oleic acid in HOSO and linoleic acid in SO significantly decreased, but the fatty acid modifications that occurred during
the repeated fryings were not only related to thermoxidative alteration but also to interactions between the bath oil and
the fat in the fried products. Data from this study also indicated that HOSO performed more satisfactorily than SO in repeated
fryings of frozen foods. Moreover, frequent addition of fresh oil throughout the deep-frying process minimized thermoxidative
and hydrolytic changes in the frying oils and extended the frying life of the oils. 相似文献
16.
This study was conducted to determine effects of genotypes and growing environment on phytosterols, triterpene alcohols, and
phospholipids (PL) in lupin (Lupinus albus L.) oil from seven genotypes grown in Maine and Virginia. The unsaponifiable lipid (UNSAP) and phospholipid (PL) fractions
ranged from 2.1 to 2.8% and from 2.6 to 2.8% of oil, respectively. UNSAP in lupin oil contained 19.9 to 28.7% sterols and
17.3 to 22.0% triterpene alcohols. Growing location significantly affected contents of total PL, PS, phosphatidylglycerol,
β-sitosterol, campesterol, and β-amyrin. Genotypic effects were significant for stigmasterol. PC (32.6 to 46.3% of PL), PE
(21.6 to 32% of PL), and PS (11.2 to 17.9% of PL) were the major PL in lupin oil. The concentration of PL classes in lupin
oil were in the following descending order: PC>PE>PS>PI>phosphatidic acid > lysophosphatidylcholine > phosphatidylglycerol
> diphosphatidylglycerol. In descending order of abundance, the sterols present in lupin oil were: β-sitosterol > campesterol
> stigmasterol > Δ5-avenasterol > Δ7-stigmastenol Lupeol was the most prominent triterpene alcohol in lupin seed oil. In general, growing environment had a much
greater influence on lupin oil characteristics than the genotypes. 相似文献
17.
Mohammad Bagher Hashemi Mehrdad Niakousari Mohammad Jamal Saharkhiz Mohammad Hadi Eskandari 《European Journal of Lipid Science and Technology》2011,113(12):1520-1526
In this study, the influence of the application of 0.025%, 0.05% and 0.075% of Zataria multiflora Boiss. essential oil (EO) on oxidative stability of sunflower oil was examined and the EO was compared to butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) during storage at 37°C and 47°C. The main components of EO were identified as carvacrol (45.6%), p‐cymene (18.1%) and thymol (16.3%). Peroxide value (PV), anisidine value (AnV) and thiobarbituric acid (TBA) value measurement in sunflower oil showed that all concentrations of EO had a lower antioxidant effect in comparison to BHA and BHT. Samples supplemented with EO concentration of 0.075% were the most stable during storage at both temperatures (p<0.05). Furthermore, Totox value, antioxidant activity (AA), stabilization factor (F) and antioxidant power (AOP) determination confirmed efficacy of this EO as antioxidant in sunflower oil. EO also was able to reduce the stable 2,2‐diphenyl‐1‐picrylhydrazyl free radical (DPPH . ) with a 50% inhibition concentration (IC50) of 34.3 ± 0.8 µg/mL. The results indicate that EO could be used as a natural antioxidant in oils for food uses. 相似文献
18.
The aims of this study were to determine whether CLA are formed during refining of vegetable oils and to study the level and
composition of CLA during heating. The effects of three refining steps (neutralization, bleaching, and deodorization) were
analyzed with respect to their effect on CLA content. Two temperatures (180 and 220°C) were used for heating; CLA appeared
only after deodorization. The level of CLA was positively influenced by temperature. More CLA were present after treatment
at 220°C than at 180°C (1.3 and 0.2% of total FA, respectively). The high temperature modified the relative proportions of
the CLA isomers. The main CLA isomers in fresh or heated oils were the trans,trans ones (mainly 9,11 and 10,12 isomers). 相似文献
19.
Negin Moradi 《分离科学与技术》2019,54(6):1043-1054
The aim of this study was to evaluate the effect of cavitation and electroporation on enzymolysis extraction of sunflower oil. The optimum extraction conditions during 2 h under enzyme-assisted extraction (EAE) with a maximum oil yield of ≈23.70 ± 0.11% were as follows: cellulase/pectinase ratio 2:1, enzyme concentration 2%, pH 4.5, liquid/solid ratio 6:1 ml/g, and extraction temperature 40°C. Under the optimized enzymatic conditions, the application of ultrasound- (250 W) and pulsed electric field- (1.2 kV/cm; 52.4 kJ/kg) assisted enzymatic extraction for 30 min significantly increased the oil extraction yield by 91.1% and 18.6%, respectively, as compared with EAE. 相似文献
20.
Crystallization of sunflower oil waxes 总被引:1,自引:0,他引:1
Activation free energies of nucleation (ΔG
c
) were calculated using induction times of crystallization measurements. Results showed that ΔG
c
decreased exponentially as wax concentration increased at a constant crystallization temperature (T
c
). In contrast, for a constant supersaturation, ΔG
c
increased from 12 to 22°C but decreased between 22 and 35°C. Melting behavior of purified waxes and solutions of purified
waxes in sunflower oil were studied by DSC after crystallization at fast and slow cooling rates (20 and 1°C/min, respectively).
Low supercooling temperatures (T
c
>65°C) showed an increase in the onset temperature (T
0
) as T
c
increased for both fast and slow cooling rates. Broader peaks were obtained for samples crystallized at a slow cooling rate
at the same T
c
. Regarding the solutions of waxes in sunflower oil, the wax concentration (supersaturation of the system) controlled crystallization
as well as T
c
. As T
c
increased, the enthalpy (ΔH) decreased at a constant wax concentration. When wax concentration decreased, ΔH decreased at a constant T
c
. For a low driving force, a small shoulder was obtained in the DSC diagrams owing to some type of fractionation. These results
showed that wax crystallization is affected by different experimental parameters, such as T
c
and cooling rate, depending on the wax concentration of the sample. 相似文献