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1.
Antioxidant capacity of extra-virgin olive oils 总被引:1,自引:1,他引:0
Paolino Ninfali Gianfranca Aluigi Mara Bacchiocca Mauro Magnani 《Journal of the American Oil Chemists' Society》2001,78(3):243-247
In this study, the oxygen radical absorbance capacity (ORAC) of vegetable oils was investigated using a spectrofluorometric
method, which measures the protection of the phenolic substances of the oil on the β-phycoerythrin fluorescence decay in comparison
with Trolox. More than 97% of the phenolic substances was extracted from the oil using methanol, and the methanolic extract
was then used for the ORAC and the total phenolics assay. We found a significant correlation between ORAC values of different
olive oils and the total amount of phenolics. For extra-virgin olive oils, maximal ORAC values reached 6.20±0.31 μmol Trolox
equivalent/g, while refined and seed oils showed values in the 1–1.5 μmol Trolox equivalent/g range. Our method is useful
to assess the quality of olive oils and to predict, in combination with the rancidity tests, their stability against oxidation. 相似文献
2.
John W. Parry Zhihong Cheng Jeffrey Moore Liangli Lucy Yu 《Journal of the American Oil Chemists' Society》2008,85(5):457-464
Cold-pressed seed flours from pumpkin, parsley, mullein, cardamom, and milk thistle were examined for total oil, fatty acid
profile of the oil, total phenolic content (TPC), scavenging activities against peroxyl (ORAC), hydroxyl (HOSC) and 2,2-diphenyl-1-picrylhydrazyl
(DPPH) (RDSC) radicals, and antiproliferative capacity against HT-29 human colon cancer cells. The cold-pressed parsley seed
flour contained a very high concentration of total oil—17.6 g/100 g flour—with primarily C18:1 fatty acid at 86.2 g/100 g
fatty acids. All other flour oils had relatively high levels of saturated fats, ranging from 39.0 to 62.9 g/100 g fatty acids.
The tested seed flours demonstrated significant TPC and free radical scavenging activities. Milk thistle seed flour had the
highest TPC value of 25.2 mg gallic acid equivalent per g flour (GAE mg/g) followed by that of parsley seed flour at 8.1 GAE
mg/g. Milk thistle seed-flour extract also had significantly higher antioxidant activities than all other extracts against
all tested radicals. The milk thistle seed-flour extract had an ORAC value of 1131 μmol trolox equivalents (TE) per g flour
(TE μmol/g), a HOSC value of 893 TE μmol/g, and an RDSC value of 61 TE μmol/g. Also, ORAC, HOSC, and TPC values were significantly
correlated (P < 0.01) under the experimental conditions. The cold-pressed milk thistle seed flour inhibited the proliferation of HT-29
cancer cells in a dose-dependent manner. Results from this study suggest that these cold-pressed seed flours may serve as
natural sources of antioxidants and may be used to improve human health. 相似文献
3.
Aleksandra Szydłowska-Czerniak Agnieszka Tułodziecka Monika Momot Barbara Stawicka 《Journal of the American Oil Chemists' Society》2019,96(4):405-419
Physicochemical characteristics, antioxidant capacity (AC), and sensory quality of rapeseed oils available on the Polish market were analyzed and compared. The fatty acid composition (saturated fatty acids = 6.91–7.58%, monounsaturated fatty acids = 64.14–66.14%, and polyunsaturated fatty acids = 27.22–30.17%), color (T420 = 54.5–83.8%), amounts of free fatty acids (0.02–0.07%), primary (PV = 0.04–2.04 meq O2 kg−1) and secondary (AV = 1.02–3.21) oxidation products, phosphorus (0.38–1.62 mg kg−1), chlorophyll (0.002–0.068 mg kg−1), and polycyclic aromatic hydrocarbons (Σ4PAH = 0.00–2.50 μg kg−1) in the commercial rapeseed oils meet the requirements of the European Food Regulation and Codex Alimentarius standards. Moreover, total phenolic content (TPC = 40.3–467.9 mg SA kg−1) in the studied oils significantly differs from each other. However, the AC of rapeseed oils was analyzed using the novel iron oxide nanoparticle-based (IONP = 5552.1 − 18,510.2 μmol TE/100 g) method and the modified ferric reducing antioxidant power (FRAP = 55.7–280.3 μmol TE/100 g), cupric reducing AC (CUPRAC = 79.6–784.0 μmol TE/100 g), 2,2-diphenyl-1-picrylhydrazyl (DPPH = 185.7–516.7 μmol TE/100 g), and 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS = 465.6–2142.6 μmol TE/100 g) assays. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied for discrimination of the refined rapeseed oils based on fatty acid composition, physicochemical parameters, AC, and sensory properties. 相似文献
4.
Aleksandra Szydłowska‐Czerniak Ryszard Amarowicz Edward Szłyk 《European Journal of Lipid Science and Technology》2010,112(7):750-760
Response surface methodology (RSM) was used to evaluate the quantitative effects of two independent variables: solvent polarity and temperature of the extraction process on the antioxidant capacity (AC) and total phenolics content (TPC) in meal rapeseed extracts. The mean AC and TPC results for meal ranged between 1181–9974 µmol TE/100 g and 73.8–814 mg sinapic acid/100 g of meal. The experimental results of AC and TPC were close to the predicted values calculated from the polynomial response surface models equations (R2 = 0.9758 and 0.9603, respectively). The effect of solvent polarity on AC and TPC in the examined extracts was about 3.6 and 2.6 times greater, respectively, than the effect of processing temperature. The predicted optimum solvent polarity of ε = 78.3 and 63.8, and temperature of 89.4 and 74.2°C resulted in an AC of 10 014 µmol TE/100 g and TPC of 863 mg SAE/100 g meal, respectively. The phenolic profile of rapeseed meal was determined by an HPLC method. The main phenolics in rapeseed meal were sinapine and sinapic acid. Refined rapeseed oils were fortified with an extract – rich in polyphenols – obtained from rapeseed meal. The supplemented rapeseed oil had higher AC and TPC than the refined oil without addition of meal extracts. However, AC and TPC in the enriched oils decreased during storage. The TPC in the studied meal extracts and rapeseed oils correlated significantly (p<0.0000001) positively with their AC (R2 = 0.9387). Practical applications: Many bioactive compounds extracted from rapeseed meal provide health benefits and have antioxidative properties. Therefore, it seems worth to consider the application of antioxidants extracted from the rapeseed meal for the production of rapeseed oils with potent AC. Moreover, antioxidants extracted from the rapeseed meal were added to refined rapeseed oil in order to enhance its AC. AC was then tested by FRAP assay. FRAP method is based on the reduction of the ferric tripyridyltriazine (Fe3+‐TPTZ) complex to the ferrous tripyridyltriazine (Fe2+‐TPTZ), and it is simple, fast, low cost, and robust method. FRAP method does not require specialized equipment and can be performed using automated, semi‐automatic, or manual methods. Therefore the proposed FRAP method can be employed by the fat industry laboratories to asses the AC of rapeseed oils and meal. 相似文献
5.
John Parry Zhigang Hao Marla Luther Lan Su Kequan Zhou Liangli Yu 《Journal of the American Oil Chemists' Society》2006,83(10):847-854
Cold-pressed onion, parsley, cardamom, mullein, roasted pumpkin, and milk thistle seed oils were characterized for their fatty
acid (FA) composition, tocopherol content, carotenoid profile, total phenolic content (TPC), oxidative stability index (OSI),
color, physical properties, and radical-scavenging capacities against peroxyl (oxygen radical-scavenging capacity) and stable
DPPH (diphenylpicrylhydrazyl) radicals. Parsley seed oil had the highest oleic acid content, 81 g/100 g total FA, and the
lowest saturated fat among the tested oils. Roasted pumpkin seed oil contained the highest level of total carotenoids, zeaxanthin,
β-carotene, cryptoxanthin, and lutein at 71 μmol/kg and 28.5, 6.0, 4.9, and 0.3 mg/kg oil, respectively. Onion seed oil exhibited
the highest levels of α- and total tocopherols under the experimental conditions. One of the parsley seed oils exhibited the
strongest DPPH scavenging capacity and the highest oxygen radical absorbance capacity (ORAC) value of 1098 μmol Trolox equiv/g
oil. However, ORAC values of the tested seed oils were not necessarily correlated to their DPPH scavenging capacities under
the experimental conditions. The highest TPC of 3.4 mg gallic acid equiv/g oil was detected in one of the onion seed oils.
The OSI values were 13.3, 16.9–31.4, 47.8, and 61.7 h for the milk thistle, onion, mullein, and roasted pumpkin seed oils,
respectively. These data suggest that these seed oils may serve as dietary sources of special FA, tocopherols, carotenoids,
phenolic compounds, and natural antioxidants.
An erratum to this article is available at . 相似文献
6.
Aleksandra Szydłowska‐Czerniak Agnieszka Tułodziecka 《Journal of the American Oil Chemists' Society》2014,91(12):2011-2019
Ultrasound‐assisted extraction (UAE) and conventional solid–liquid extraction were applied to extract total antioxidants from two rapeseed varieties. The antioxidant capacities (AC) of winter and spring rapeseed cultivars were determined by four different analytical methods: ferric reducing antioxidant power (FRAP), cupric reducing antioxidant capacity (CUPRAC), 2,2′‐diphenyl‐1‐picrylhydrazyl (DPPH), 2,2′‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS). The average AC of the studied rapeseed cultivars ranged between 4.21–10.03 mmol Trolox (TE)/100 g, 7.82–10.61 mmol TE/100 g, 8.11–51.59 mmol TE/100 g, 22.48–43.13 mmol TE/100 g for FRAP, CUPRAC, DPPH and ABTS methods, respectively. There are positive correlations between total phenolics (TPC = 804–1625 mg sinapic acid (SA)/100 g) and AC of the studied rapeseed extracts (r = 0.2650–0.9931). Results of the principal component analysis (PCA) indicate that there are differences between the total amounts of antioxidants in rapeseed samples extracted by different extraction techniques. Rapeseed extracts obtained after 18 min of ultrasonication revealed the highest content of total antioxidants. The UAE is a very useful, efficient and rapid technique of oilseed samples preparation for determination of AC by different analytical methods. 相似文献
7.
Ruijie Liu Mengyao Lu Tao Zhang Zhiyan Zhang Qingzhe Jin Ming Chang Xingguo Wang 《European Journal of Lipid Science and Technology》2020,122(2)
Micronutrients (tocols, sterols, and total phenolic) and antioxidant activities of 15 varieties of common vegetable oil samples obtained from different countries are investigated. All methanol extracts are assayed for total antioxidant ability and cellular antioxidant activity (CAA) using oxygen radical absorbance capacity (ORAC) method and CAA assay. CAA has been widely used in the evaluation of food antioxidants recently. It quantifies antioxidant capacity utilizing a HepG2 cell model, which is more biologically representative. Linseed and sesame oils show much higher CAA values than the others tested; however, levels of walnut, sunflower, and coconut oils are extremely low, which are hard to be quantified. A significant correlation between the ORAC and CAA values and total phenolic content (p < 0.05) is observed. High‐phenolic olive oil has the highest level of phenolics and the highest ORAC, while linseed oil has the highest CAA value. Based on this, choosing proper edible oil consumption may reduce oxidative damage of human body and promote the precision processing of edible oil such as retaining beneficial ingredients moderately. Practical Application: This study demonstrates the evaluation of the universality of vegetable oils by the cellular antioxidant model and provides a data reference for the selection of edible oils with excellent antioxidant properties. 相似文献
8.
Paolino Ninfali Mara Bacchiocca Enrica Biagiotti Maurizio Servili Gianfrancesco Montedoro 《Journal of the American Oil Chemists' Society》2002,79(10):977-982
The induction period (IP), determined using accelerated methods such as the Rancimat test, is a parameter that has been used
to predict the shelf life of virgin olive oil. The oxygen radical absorbance capacity (ORAC) has recently been proposed as
a quality index of virgin olive oil because it measures the efficiency of phenolic compounds in the protection against peroxyl
radicals. This study aims to investigate relationships between the ORAC and IP values and proposes ORAC as a new parameter
of virgin olive oil stability. The concentrations of phenolics, o-diphenols, tocopherol, β-carotene, lutein, and ORAC and IP values were determined in 33 virgin olive oils. Regression analyses
showed that both ORAC and IP values correlate with total phenols and o-diphenols with highly significant indices, whereas the correlations of both ORAC and IP with tocopherols, β-carotene, and
lutein were not significant. The ORAC values correlate with the IP values with low but significant indices (R=0.42; P<0.02). The results confirm the key role of phenolic compounds in accounting for the shelf life of virgin olive oil and suggest
that the ORAC parameter may be used as a new index of quality and stability. 相似文献
9.
Total Phenolics of Virgin Olive Oils Highly Correlate with the Hydrogen Atom Transfer Mechanism of Antioxidant Capacity
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Cristiano Augusto Ballus Adriana Dillenburg Meinhart Francisco Alberto de Souza Campos Jr. Helena Teixeira Godoy 《Journal of the American Oil Chemists' Society》2015,92(6):843-851
Polar extracts of extra‐virgin olive oils (EVOO) contain a large number of phenolic compounds with antioxidant properties. The antioxidant capacity can be measured by different reaction mechanisms, as the single electron transfer (SET) or the hydrogen atom transfer (HAT). In this work, the total phenolic content (TPC) by the Folin‐Ciocalteu method and its correlation with four antioxidant capacity assays (FRAP, ABTS, DPPH? and ORAC) were evaluated for EVOO polar extracts. It was observed that the higher the total phenolic compounds in the EVOO extracts, the higher the antioxidant capacities, regardless of the method employed. The reaction mechanism observed for TPC by Folin‐Ciocalteu method and also for FRAP, ABTS and DPPH? antioxidant capacity assays is a single electron transfer, thus, a high correlation among their results is expected. However, the correlation between TPC and ORAC results was also high and significant, allowing to conclude that EVOO phenolic compounds are able to react by the hydrogen atom transfer mechanism, which indicates that they can act as effective radical chain‐breaking antioxidants. These results suggest that, for the EVOO polar extracts, TPC by Folin‐Ciocalteu and ORAC assays could be sufficient to evaluate their in vitro antioxidant capacity. 相似文献
10.
Josep Serra Bonvehí Arrate Lacalle Gutiérrez 《Journal of the American Oil Chemists' Society》2011,88(9):1387-1395
The purpose of this study was to evaluate the antioxidant activity (AA) of 19 propolis extracts prepared in different solvent
(ethanol and propylene glycol). It was observed that all the samples tested had AA, although results varied considerably between
extracts, i.e. 420–1,430 μmol Trolox/g (ABTS), 108–291 mg ascorbic acid/g (DPPH), and 1,573–4,669 μmol iron++ sulfate/g (FRAP). The ethanol may enhance the potency of the AA, and the correlation coefficient between total phenolic content
(TPC) (200–340 mg/g propolis extracts) and AA was statistically significant. Total flavonoids ranged from 72 to 161 mg/g propolis
extracts. The results indicate that TPC and flavonoids contributed to AA. 相似文献
11.
Samia Dabbou Faten Brahmi Ameni Taamali Manel Issaoui Youssef Ouni Mohamed Braham Mokhtar Zarrouk Mohamed Hammami 《Journal of the American Oil Chemists' Society》2010,87(10):1199-1209
The effects of the contents of lipids, pigments, α-tocopherol and phenols were studied in relation to the antioxidant capacity
of five virgin olive oils obtained from five olive cultivars planted in Tunisia (Arbequina, Koroneiki, Leccino, Oueslati and
Chemchali). The antioxidant capacities were evaluated by two different radical scavenging activities: radical scavenging activity
by the DPPH assay (RSA-DPPH) and total antioxidant status by the ABTS test (TAA-ABTS). The highest contents of antioxidant
compounds (75.96, 10.34, 6.32, 15.39 and 241.52 mg kg−1 for oleic acid, O/L ratio, carotenes, chlorophylls and total phenols, respectively) were found for the Koroneiki cultivar
except for α-tocopherol and o-diphenols, which had the highest contents (369 and 160.7 mg kg−1, respectively) in the Leccino and Chemchali cultivars (cvs). Furthermore, the highest antioxidant capacity in virgin olive
oil was observed in the Koroneiki cultivar (0.24 mmol TE kg−1) followed by the Chemchali and Leccino cvs (0.22 and 0.13 mmol TE kg−1) for the TAA-ABTS test. However, the RSA-DPPH activity was higher for the Chemchali cultivar (19.9%) than for the Koroneiki
and Leccino cvs (18.4 and 13.5%, respectively). Correlation between these capacities and the oil composition revealed that
they were mainly influenced by the carotene content, followed by chlorophyll and phenolic contents where the ABTS test was
more pronounced. Then, the antioxidant capacity of the virgin olive oils was correlated with polar components and the lipid
profile which are important for its shelf life. 相似文献
12.
Effect of Hydrothermal Treatment of Rapeseed on Antioxidant Capacity of the Pressed Rapeseed Oil 总被引:1,自引:0,他引:1
Aleksandra Szydłowska-Czerniak György Karlovits Ágnes Sosna-Sárdi Csilla Dianoczki Edward Szłyk 《Journal of the American Oil Chemists' Society》2009,86(8):817-825
Response surface methodology (RSM) was used to evaluate the quantitative effects of two independent variables, rapeseed moisture
content and conditioning temperature, on the antioxidant capacity (AC) and total phenolic (TPC), tocopherol (TTC), and phosphorus
contents (PC) in the pressed rapeseed oils. The mean AC results for the crude rapeseed oils ranged from 199.8 to 947.2 μmolTE/100 g.
TPC and PC in the crude rapeseed oils correlated significantly (P < 0.01) and positively with AC of oils (R
2 = 0.9498 and 0.4396, respectively). The experimental results of AC, TPC, and PC were close to the predicted values calculated
from the polynomial response surface model equations (R
2 = 0.9801, 0.9747 and 0.9165, respectively). The effect of oil processing temperature on AC and TPC was about 1.5 times greater
than the effect of moisture level in rapeseed. 相似文献
13.
Frying Quality Characteristics of French Fries Prepared in Refined Olive Oil and Palm Olein 总被引:2,自引:0,他引:2
Elham Tabee Margaretha Jägerstad Paresh C. Dutta 《Journal of the American Oil Chemists' Society》2009,86(9):885-893
The objective of this study was to compare two oils with different polyunsaturated/saturated (P/S) fatty acid ratios, refined
olive oil (P/S 0.75) and palm olein (P/S 0.25), in frying French fries. The chemical qualities of the oil residues extracted
from the French fries were assayed for five consecutive batches fried at 1-h intervals. The levels of total polar compounds,
free fatty acids, p-anisidine value and phytosterol oxidation products (POPs) were elevated in French fries fried in both oils. The level of total
polar compounds increased from 4.6 in fresh refined olive oil to 7.3% in final batches of French fries. The corresponding
figures for palm olein were 9.8–13.8%. The level of free fatty acid in fresh refined olive oil increased from 0.06 to 0.11%
in final products. These figures for palm olein were 0.04–0.13%. The p-anisidine value increased from 3.7 to 32.8 and 2.5 to 53.4 in fresh oils and in final batches of French fries in refined
olive oil and palm olein, respectively. The total amount of POPs in fresh refined olive oil increased from 5.1 to 9.6 μg/g
oil in final products. These figures were 1.9 to 5.3 μg/g oil for palm olein. 相似文献
14.
A simple and reliable high-performance liquid chromatography method for the analysis of diesel oil in contaminated edible
oils is described. Analysis performed using a diol column with a mobile phase of heptane and isopropanol (94∶6, vol/vol).
Although baseline separation between diesel and other background fluorescent components was not achieved, quantitation was
still possible using baseline integration. The method is linear over the range of 5–1000 μg/g with a correlation coefficient
(r
2) of 0.9984. Average recoveries from spiked edible oils were 94.4–101.3%, with a limit of quantitation (LOQ) of 5 μg/g for
sunflower oil, palm olein, and groundnut oil. Corn oil has a higher content of ester components, thus, LOQ was slightly worse
(40 μg/g). The applicability of the method was confirmed by gas chromatography-mass spectroscopic detection to show the presence
of diesel hydrocarbons in the suspected contaminated crude palm oil. This procedure provides a simple and sensitive method
for determining diesel oil concentration in contaminated edible oils without prior sample cleanup or extraction. 相似文献
15.
Felib Y. Iskander 《Journal of the American Oil Chemists' Society》1993,70(8):803-805
Instrumental neutron activation analysis was used to determine the concentration of As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hg, K,
Na, Rb, Sb, Sc, Se, Sr and Zn in almond, sunflower, peanut, sesame, linseed, soy, corn and olive oils, as well as in three
margarine brands. The concentration of As, Ba, Ce, Cs, Eu, Hg, Rb, Se and Sr were below the system detection limit under the
experiment conditions. Chromium was detected only in one of the margarine samples (171 μg/g); Sb only in corn oil (18 ng/g)
and Sc only in linseed oil (19 ng/g). Cobalt, Fe, K, Na and Zn were detected in all oil and margarine samples investigated.
The concentration ranges for Co, Fe, K, Na and Zn in oils were: 0.016–0.053; 4.45–19.1; 5.93–47.2; 2.44–12.9 and 0.48–1.54
μg/g, respectively. For margarine, the concentration ranges for Co, Fe, K, Na and Zn were 0.09–0.012; 4.53–10.6; 58.3–1140;
13.2–9870 and 0.38–0.47 μg/g, respectively. The elemental contents of the analyzed samples are within the ranges reported
in the literature for edible oils and fats. 相似文献
16.
Ilknur Demirtas Ebru Pelvan İbrahim Sani Özdemir Cesarettin Alasalvar Erdal Ertas 《European Journal of Lipid Science and Technology》2013,115(6):641-647
Grape seed oils of seven native Turkish cultivars (namely Atfi, Mazruna, Black Kerkü?, Zeyti, Verdani, Karfoki, and Kerkü?) were evaluated for their fatty acids, tocols, phytosterols as well as total phenolics and oxygen radical absorbance capacity (ORAC) values. Among the fatty acids, linoleic acid (18:2ω6) was the most abundant (56.38–68.56%), followed by oleic acid (16.45–29.38%, 18:1ω9), palmitic acid (8.19–9.44%, 16:0), and stearic acid (3.74–4.98%, 18:0). Total tocopherols and tocotrienol amounts varied in the range of 102.30–305.43 and 251.47–468.22 mg/kg, respectively. Beta‐sitosterol was the most abundant sterol among grape cultivars whose concentration ranging from 64.19 to 71.62%. Total phenolic content ranged from 2.19 to 4.70 mg of gallic acid equivalents/100 g oil, being lowest in Zeyti and highest in Verdani. With respect to antioxidant activities, a large variation in ORAC values was observed among grape seed oils (ranging from 1048 µmol of Trolox equivalents (TE)/100 g in Karfoki to 2569 µmol of TE/100 g in Mazruna). Practical applications: The crude grape seed oils extracted from different cultivars are a good source of nutrients, fat‐soluble bioactives, and health‐promoting components. 相似文献
17.
The purpose of this investigation was to study differences in the chlorophyll, carotenoid, and phenolic fractions of virgin
olive oils from the Arbequina variety cultivated in different olive growing areas of Spain. Virgin olive oil from Lleida was
less heavily pigmented, and these oils showed more negative values for the ordinate a* (of the CIELAB colorimetric system). Pheophytin a was the major chlorophyll pigment, and lutein was the major component of the carotenoid fraction in all oils analyzed. The
chlorophyll a concentration in virgin olive oils from Lleida was 700 μg kg−1, but was 175 μg kg−1 in oils from Jaén, and 200 μg kg−1 in oils from Tarragona. Finally, the chlorophyll a/chlorophyll b ratio was 9 in oils from Lleida and around 0.6 in the other two Arbequina olive oils. In relation to the phenolic fraction,
the hydroxytyrosol and tyrosol contents were significantly higher in olive oils from Jaén (grown at higher altitude and precipitation
rates). The secoiridoid derivatives showed a significantly higher concentration in olive oils from Tarragona, probably due
to the low altitude where they grow, and finally the ratio of (dialdehydic form of elenolic acid linked to tyrosol)/lignans
had a value of 1.4 in olive oils from Lleida, whereas this value was around 0.7 in the other Arbequina olive oils. 相似文献
18.
Development of steryl ester analysis for the detection of admixtures of vegetable oils 总被引:2,自引:0,他引:2
Michael H. Gordon Luke A. D. Miller 《Journal of the American Oil Chemists' Society》1997,74(5):505-510
The steryl ester content and composition of 28 samples from 10 vegetable oil types have been determined by isolation of the
steryl esters by high-performance liquid chromatography and analysis by gas chromatography. The oils can be classified into
oils with a high content (>4000 mg/kg) of steryl esters (corn and rapeseed); oils with a medium content (1400–2400 mg/kg)
of steryl esters (sunflower oil and high-oleic sunflower oil); and oils with a low content (<1200 mg/kg) of steryl esters
(safflower, soybean, cottonseed, groundnut, olive, and palm oils). The composition of the steryl ester fraction varies to
a greater extent for different oil types than for different varieties of the same oilseed. The developed method is promising
for authentication of some oils, and is particularly suitable for detecting admixtures of low levels of corn or rapeseed oils. 相似文献
19.
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
20.
Svjetlana Luterotti Mladen Franko Dane Bicanic 《Journal of the American Oil Chemists' Society》2002,79(10):1027-1031
Isocratic reversed-phase HPLC with thermal lens spectrometric (TLS) detection enabled identification of linseed, olive, sesame,
and wheat germ vegetable oils to control the authenticity of the oils based on characteristic carotenoid/carotene profiles.
Four characteristic regions of carotenoids (i.e., lutein, xanthophyll, carotene, and lycopene) have been identified in each
type of oil. The concentrations of total β-carotene (BC) and α-carotene (AC), together with trans-to cis-isomers of β-carotene (TBC/CBC) and BC/AC ratios were shown to be reliable and useful indices for fast screening of oils
for nutritional quality. The oil TBC/CBC ratio and the BC concentration (in μg/mL) should meet the following numerical criteria:
linseed (≽2∶1, ≽1.7), olive (≽3∶1, ≽0.4), sesame (≽1∶1, ≽0.1), and wheat germ oil (≽1∶1, ≽1.7). Based on the above criteria,
unsatisfactory olive oils differed significantly from the consumable ones. Likewise, the concentration of AC in consumable
wheat germ and sesame oil should not be lower than 0.6 and 0.02 μg/mL, respectively. The AC level in safflower oil should
not be higher than 0.04 μg/mL. The BC/AC ratios exceeding 3∶1, 6∶1, and 8∶1 should be used as an additional quality requirement
for consumable wheat germ, sesame, and safflower oil, respectively. 相似文献