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1.
Microwave roasting effects on the physico-chemical composition and oxidative stability of sunflower seed oil 总被引:1,自引:0,他引:1
Fozia Anjum Farooq Anwar Amer Jamil M. Iqbal 《Journal of the American Oil Chemists' Society》2006,83(9):777-784
The purpose of the present study was to explore the influences of microwave heating on the composition of sunflower seeds
and to extend our knowledge concerning the changes in oxidative stability, distribution of FA, and contents of tocopherols
of sunflower seed oil. Microwaved sunflower seeds (Helianthus annuus L.) of two varieties, KL-39 and FH-330, were extracted using n-hexane. Roasting decreased the oil content of the seeds significantly (P<0.05). The oilseed residue analysis revealed no changes in the contents of fiber, ash, and protein that were attributable
to the roasting. Analysis of the extracted oils demonstrated a significant increase in FFA, p-anisidine, saponification, conjugated diene, conjugated triene, density, and color values for roasting periods of 10 and
15 min. The iodine values of the oils were remarkably decreased. A significant (P<0.05) decrease in the amounts of tocopherol constituents of the microwaved sunflower oils also was found. However, after
15 min of roasting, the amount of α-tocopherol homologs was still over 76 and 81% of the original levels for the KL-39 and
FH-330 varieties, respectively. In the same time period, the level of σ-tocopherol fell to zero. Regarding the FA composition
of the extracted oils, microwave heating increased oleic acid 16–42% and decreased linoleic acid 17–19%, but palmitic and
stearic acid contents were not affected significantly (P<0.05). 相似文献
2.
Oxidation of sunflower oil during storage 总被引:1,自引:0,他引:1
Guillermo H. Crapiste Marta I. V. Brevedan Amalia A. Carelli 《Journal of the American Oil Chemists' Society》1999,76(12):1437-1443
Effects of temperature and oxygen concentration on oxidative deterioration during storage of crude sunflower oils, obtained
by pressing and solvent extraction, were studied. Oxidation was monitored through several analytical and chromatographic methods
that determine chemical and physical changes or analyze specific oxidation compounds at different stages of the process: peroxide
value, p-anisidine value, free fatty acids, weight gain, total content and distribution of polar compounds, and composition of fatty
acids. Extracted oil showed a higher oxidative stability than pressed oil. Oxidative deterioration was strongly dependent
on temperature, oxygen availability, and the ratio of exposed surface to sample volume. A kinetic model of two series reactions
was developed to represent oxidation rate in terms of peroxide value, the reaction rate constants and their temperature dependence
being evaluated by nonlinear regression. Finally, good correlations between the percentage of polar compounds or oxidized
triglyceride monomers and the peroxide value were found. 相似文献
3.
Pan-frying is a popular frying method at home and in many restaurants. Pan-frying stabilities of two frying oils with similar
iodine values (IV)—mid-oleic sunflower oil (NuSun oil; IV=103.9) and a commercial canola oil (IV=103.4)—were compared. Each
oil sample was heated as a thin film on a Teflon-coated frying pan at ∼180°C to a target end point of ≥20% polymer. High-performance
size-exclusion chromatography analysis of the mid-oleic sunflower and canola oil samples indicated that the heated samples
contained 20% polymer after approximately 18 and 22 min of heating, respectively. The food oil sensor values increased from
zero to 19.9 for the canola sample and from zero to 19.8 for the mid-oleic sunflower sample after 24 min of heating. The apparent
first-order degradation rate for the mid-oleic sunflower sample was 0.102±0.008 min−1, whereas the rate for the canola sample was 0.092±0.010 min−1. The acid value increased from approximately zero prior to heating to 1.3 for the canola sample and from zero to 1.0 for
the mid-oleic sunflower sample after 24 min of heating. In addition, sensory and volatile analyses of the fried hash browns
obtained from both oils indicated there were no significant differences between the two fried potato samples. 相似文献
4.
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
5.
Kang Tian Purnendu K. Dasgupta William D. Shermer 《Journal of the American Oil Chemists' Society》2000,77(3):217-222
A gas-phase flow injection analysis (FIA) method for the direct determination of the oxidative stability of solid fat/oil samples is described. Samples are confined with a low level of oxygen in a reactor of adjustable temperature. The oxygen consumption by the sample is automatically monitored after a preset period. The temperature-dependent data exhibit Arrhenius behavior. Normally, it is difficult to directly determine the stability at ambient temperatures because of inordinately long time requirements. The close correspondence to Arrhenius behavior makes it possible to use the results obtained at higher temperature to calculate the stability of samples at lower temperature conditions, such as at ambient storage temperature. The effects of sample size, sample particle size, sample fat content and the reproducibility of the method over time were studied using synthetic and bone meal samples. The oxygen consumption was found to be linearly dependent on the amount of sample taken, inversely dependent on the particle diameter, and independent of the exact lipid content, given some minimum lipid content. The results exhibited high day-to-day reproducibility. The gasphase FIA system developed in this work is easy to operate. Compared with the currently used method, the sample throughput rate is much faster (2–3h for complete multitemperature characterization of a sample) and the sample requirement is much lower (∼1 g). Furthermore, it eliminates the need to extract and recover the fat from the sample for further processing as is required by the other methods commonly used to measure oxidative stability. 相似文献
6.
Gloria Márquez-Ruiz Rafael Garcés Manuel León-Camacho Manuel Mancha 《Journal of the American Oil Chemists' Society》1999,76(10):1169-1174
Thermoxidative stability was evaluated in triaclyglycerols (TAG) from the oils of the mutant sunflower lines CAS-3, CAS-4,
and CAS-8 (with a high percentage of stearic acid), CAS-5 (with a high percentage of palmitic acid), all from standard highlinoleic
genetic backgrounds, and the mutant sunflower line CAS-12 (with a high percentage of palmitic acid), from a high-oleic genetic
background. These oils contained unusually high contents of TAG molecular species with one or two saturated fatty acids at
the sn-1,3 positions. Purified total TAG devoid of tocopherols were subjected to controlled thermoxidative treatment at 180°C. Polymerized
TAG were determined at 2-h intervals for 10 h. After this time, total polar compounds, oxidized TAG monomers, TAG dimers,
and TAG oligomers were determined. TAG from highly saturated sunflower oils with levels of linoleic acid similar to those
found in conventional sunflower oils (40–50%) showed enhanced thermal stability. In these TAG, the amount of polar compounds
formed during the thermoxidative treatment was similar to that formed in the high oleic acid line. Excellent results were
obtained for the TAG of the CAS-12 oil, which had the highest thermal stability, producing half the amount of polar compounds
as the conventional line and less than two-thirds that of the high-oleic line. 相似文献
7.
Pinar Gumus Eric A. Decker Medeni Maskan 《Journal of the American Oil Chemists' Society》2023,100(5):413-420
In this study, oxidatively stable minimal neutralized sunflower seed oils were produced using three chemicals (Ca(OH)2, MgO, and Na2SiO3) under previously determined optimal process conditions. Lipid oxidation rates at these optimum conditions were compared to the oils neutralized with NaOH (0.20%, 40°C, 15 min). It was concluded that the oils neutralized by NaOH had the shortest hydroperoxide and hexanal lag phases, thus were the least stable oils. Oils neutralized by Ca(OH)2, MgO, and Na2SiO3 had lower FFA and higher oxidative stability than oil neutralized by NaOH. The study focused on which weak alkaline has higher oxidation stability and minimum FFA content and maximum acceptable tocopherol content. The oil neutralized by Ca(OH)2 had the lowest FFA value and highest total phenolics and α-tocopherol contents and it had better oxidative stability than oil neutralized by NaOH. It suggests that Ca(OH)2 could be more effective in producing a high quality oil. 相似文献
8.
Blends of sunflower oil (SFO) and rice bran oil (RBO) were evaluated for their stability. Additionally, known amounts of natural antioxidants extracted from RBO were added to SFO, and their protective effect was compared to that of the blends. The results found indicate that by raising the amount of RBO, from 10 to 50%, an increase of OLO, OLP, PPL, OOO, PPO, OPO, 18:1 and 16:0 occurred, followed by a decrease of LLL, LLO, and 18:2. These changes in fatty acid and triacylglycerol (TAG) composition led to an increase of the oil stability index at 120 °C and a reduction of polymer TAG formation in the heated blends at 180 °C during 8 h. A comparable protective effect of natural antioxidants to that of blending was observed in a 50 : 50 blend, by remarkably increasing the induction period. 相似文献
9.
Monica M. Neumann Silvia N. Fusero Norman A. García 《Journal of the American Oil Chemists' Society》1991,68(9):662-665
The susceptibilities of crude soybean, sunflower and peanut oils to singlet oxygen photooxidation were determined in a kinetic
study. The accumulation of photosensitized hydroperoxides, determined spectroscopically, and the quenching of singlet molecular
oxygen phosphorescence by the crude oils and their fatty acid methyl esters were compared.
The relative tendency to photooxidation for the oils and the methyl esters was soybean ≫ sunflower > peanut. This trend was
independent of the method employed in the determination of initial photodamaging.
Soybean oil was demonstrated to be the most unstable product, not only due to the presence of highly unsaturated fatty acids,
but also due to the absence of natural constituents, capable of providing a protective antioxidant effect. This protection
was more effective in sunflower and peanut oils. 相似文献
10.
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
11.
A biphasic oil-aqueous system for FAME production by enzymatic catalysis was studied. The transesterification of sunflower oil with methanol was catalyzed by free or immobilized lipases from Rhizomucor miehei (Palatase 20 000 L) and Humicola insolens (Lipozyme TL 100 L). The effects of protein amount, temperature, pH, and molar ratio of methanol to sunflower oil on the enzymatic reaction using free lipase were evaluated; the best results were obtained with H. insolens, at pH 5, 40°C, and 36.8 mg of protein. By using this lipase immobilized in Hypol® 2002 (64. 8 mg of protein) at a 6∶1 methanol/oil molar ratio and a 2∶1 volumetric oil/water phase ratio, an ester content of 96.1% and a conversion of 91.2% were achieved. The immobilized lipase could be reused, although a 30% reduction in conversion efficiency was observed after four uses. 相似文献
12.
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
13.
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
14.
rGO-Fe3O4活化过硫酸盐处理酸性红73 总被引:2,自引:0,他引:2
采用共沉淀法制备了还原石墨烯纳米片和磁铁矿复合材料(rGO-Fe3O4)。利用X射线衍射(XRD)、X射线光电子能谱(XPS)和透射电镜(TEM)对其进行了表征。以酸性红73(AR73)为目标物,研究了rGO-Fe3O4活化过硫酸盐(PS)处理酸性红73的效能,考察了催化剂投加量、PS浓度、溶液初始pH以及反应温度的影响。结果表明,室温下催化剂投加量为1.0 g/L、PS的浓度为1.0 g/L及初始pH为6.9时,10 min内50 mg/L酸性红73的脱色率达到100%。淬灭实验结果表明rGO-Fe3O4/PS反应体系同时存在SO4-?、?OH和单线态氧1O2,其中1O2的氧化反应起主导作用。复合材料rGO-Fe3O4不但活性高,而且便于分离,应用前景良好。 相似文献
15.
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
16.
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
17.
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
18.
Karl‐Heinz Wagner Bettina Isnardy Ibrahim Elmadfa 《European Journal of Lipid Science and Technology》2003,105(5):219-224
This study was conducted to assess the reduction of life time and quality of poppy seeds considering a mechanical damage, which may occur during harvesting. Vienna, Vienna, Austria Poppy seeds were crushed to receive 90%, 80%, 70%, 60% and 50% intact seeds, the undamaged 100% intact seeds served as controls. The samples were stored at 40 °C for 175 d and oxidation experiments performed periodically by assessing conjugated dienes, p‐anisidine reactive products, the iodine value, the acid value and γ‐tocopherol content. With increasing degree of mechanical damage the shelf life declined, the oxidation products were formed more rapidly and the main antioxidant in poppy seeds γ‐tocopherol was consumed. Considering the reduction of life time by including all quality parameters the shelf life of the 10% damaged seeds was reduced by 50.5%. This reduction was reached up to 82% for the 50% damaged seeds compared to the control. A high correlation was found between the increase in oxidation products and the degradation of γ‐tocopherol. This study show that increased damage during harvesting (10‐50%) is responsible for a faster loss of product quality especially in seeds containing high amounts of polyunsaturated fatty acids like poppy seeds. 相似文献
19.
Ivana Niklov tefan Schmidt Katarína Habalov Stanislav Sekretr 《European Journal of Lipid Science and Technology》2001,103(5):299-306
Antioxidative activities of evening primrose seed meal extracts in sunflower and rapeseed oils were compared with that of commercially used antioxidants, namely butylated hydroxytoluene (BHT), ascorbylpalmitate as well as Grindox‐118. The study was carried out under Schaal oven conditions at 60 °C and the weight gain was followed up by p‐anisidine value measurement following the oxidation. An Oxidograph apparatus monitored the oxidation of oils at 110 °C. Among the examined extracts, the ethyl acetate extract (0.2%), containing only 87 mg/g of total phenolics, exhibited a stronger antioxidant activity than BHT (0.01%) and effectively stabilised both oils. A strong antioxidative effect was also noted for the ethanol‐ethyl acetate extract (168 mg/g of total phenolics). The study showed that addition of ethyl acetate and ethanol‐ethyl acetate extracts could extend the sunflower and rapeseed oils shelf‐life by protecting oils from further decomposition that naturally occurs during thermal treatments. 相似文献