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1.
Use of high-resolution 13C nuclear magnetic resonance spectroscopy for the screening of virgin olive oils 总被引:2,自引:0,他引:2
Rosario Zamora Virginia Alba Francisco J. Hidalgo 《Journal of the American Oil Chemists' Society》2001,78(1):89-94
13C Nuclear magnetic resonance (NMR) spectra of 104 oil samples were obtained and analyzed in order to study the use of this
technique for routine screening of virgin olive oils. The oils studied included the following: virgin olive oils from different
cultivars and regions of Europe and north Africa, and refined olive, “lampante” olive, refined olive pomace, high-oleic sunflower,
hazelnut, sunflower, corn, soybean, rapeseed, grapeseed, and peanut oils, as well as mixtures of virgin olive oils from different
geographical origins and mixtures of 5–50% hazelnut oil in virgin olive oil. The analysis of the spectra allowed us to distinguish
among virgin olive oils, oils with a high content of oleic acid, and oils with a high content of linoleic acid, by using stepwise
discriminant analysis. This parametric method gave 97.1% correct validated classifications for the oils. In addition, it classified
correctly all the hazelnut oil samples and the mixtures of hazelnut oil in virgin olive oil assayed. All of these results
suggested that 13C NMR may be used satisfactorily for discriminating some specific groups of oils, but to obtain 100% correct classifications
for the different oils and mixtures, more information than that obtained from the direct spectra of the oils is needed. 相似文献
2.
13C NMR spectra of oil fractions obtained chromatographically from 109 vegetable oils were obtained and analyzed to evaluate
the potential use of those fractions in the classification of vegetable oils and to compare the results with the NMR analysis
of complete oils. The oils included the following: virgin olive oils from different cultivars and regions of Europe and north
Africa; “lampante” olive, refined olive, refined olive pomace, hazelnut, rapeseed, high-oleic sunflower, corn, grapeseed,
soybean, and sunflower oils; and mixtures of virgin olive oils from different geographical origins. Oils were divided into
two sets of samples. The training set (98 samples) was employed to select the variables that resulted in significant discrimination
among the different oil classes. By using stepwise discriminant analysis, more than 98% of correct validated assignments were
obtained; these results were confirmed when applied to the test set (11 blind samples). Results suggest that the use of oil
fractions considerably increases the discriminating power of NMR in the analysis of vegetable oils. 相似文献
3.
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
4.
G. Andersson 《European Journal of Lipid Science and Technology》1973,75(1):7-13
Fatty Acid Pattern of Various Oil Plants The fatty acid composition of seeds of important Swedish Oil plants, namely winter and summer rape, winter and summer turnip rape, white mustard and poppy, are compared with the composition of some important vegetable oils, which are imported to Sweden, such as soybean, sunflower, peanut and cottonseed oils. The aim of the breeding experiments was to improve the quality of crucifer oils. The oil sought for was to contain little erucic and linolenic acids, and a higher amount of linoleic acid. During the breeding work at Svalöf, new varieties of rape were developed whose oil was very similar to peanut oil. These oils had little or no erucic acid, little linolenic acid and a higher content of oleic and linoleic acids. It is more difficult to attain an increase in linoleic acid content with simultaneous decrease in linolenic acid than the increase in linoleic with simultaneous decrease of erucic acid. 相似文献
5.
6.
In the present study, changes in phospholipid compositions of liver microsomes, erythrocyte membranes, platelets, aorta, cardiac
muscle and brain of rats fed olive oil were compared with those of rats fed sunflower oil. Four groups of rats starting at
weaning were fed for four weeks a basal diet containing 5 or 25% olive oil or sunflower oil. We found that oleic acid was
higher and linoleic acid was lower in membrane phospholipids of olive oil fed rats compared to sunflower oil fed rats. Polyunsaturated
fatty acids of the n−3 series were markedly elevated in all tissues of rats on the olive oil diets relative to those on the
sunflower oil diets. The results are consistent with a lower linoleic/linolenic acid ratio induced by the olive oil diets,
suggesting a positive correlation between olive oil ingestion and n−3 polyunsaturated fatty acid levels in cell and tissue
lipids. The study suggests that an adequate intake of olive oil may enhance the conversion of n−3 fatty acids. 相似文献
7.
Male Wistar rats were fed semipurified diets containing 20% fat for 25 weeks. Ten different oils or oil blends were employed,
including rapeseed oils, simulated rapeseed-type oils, and modified rapeseed-type oils. Safflower, soybean, and hydrogenated
coconut oils served as control oils. Histopathological examination of the cardiac tissue was conducted at the end of the study
and an incidence-severity rating assigned to the lesions induced by each fat. Oils containing high levels of erucic acid (26–30%)
induced the most severe cardiac necrosis, irrespective of the source of erucic acid (rapeseed oil or nasturtium oil). Increasing
the linoleic: linolenic acid ratio of the high erucic oils to that of soybean oil failed to reduce necrosis, but the absence
of linolenic acid from a high erucic acid oil blend resulted in a markedly reduced lesion incidence-severity rating, comparable
to those obtained for low erucic acid rapessed oil and soybean oil which were similar. Lowest lesion incidence was obtained
with safflower oil and hydrogenated coconut oil. We have postulated that linolenic acid plays a role in the etiology of cardiac
necrosis observed when rats are fed diets containing low erucic acid rapeseed oils. 相似文献
8.
Costanza Aghemo Andrea Albertino Roberto Gobetto Carola Lussiana Antonino De Maria Deborah Isocrono 《European Journal of Lipid Science and Technology》2012,114(12):1409-1416
Piedmont olive oils collected in 2010 were characterized, for the first time, in terms of their fatty acid profile using GC and 1H NMR and compared to other oils from five Italian regions. Applying NMR spectroscopy on the olive oil samples, without manipulation, it is possible to calculate the proportion of the different acyl groups in the oil samples. As the area of the signals is proportional to the number of each type of proton in the sample, saturated, monounsaturated (oleic acid) and polyunsaturated (linoleic and linolenic acids) fatty acids were determined. All analyzed samples can be categorized as virgin olive oil extra quality according to the oleic/linoleic ratio. Based on a preliminary geographical investigation, olive oils produced in the North of Italy show a good separation from those from Central and Southern regions. Practical applications : Oil characterization of new products is the basis for further nutritional and food technological investigations and the quality of edible oils is of great concern especially for products available on the market. The two adopted techniques show a remarkable agreement in the evaluation of fatty acid composition of oil samples. Also, this research, by means of 1H NMR, provides information on geographical origin of the olive oils of Northern Italian regions with respect to Central and Southern regions. 相似文献
9.
Mengguo Yan Elizabeth M. Frank Eric W. Cochran 《Journal of the American Oil Chemists' Society》2018,95(2):209-216
In this article, we investigate the role of triacylglycerol composition on the properties of epoxidized vegetable oils and the kinetics of the epoxidation process under conditions comparable to commercial epoxidation. Commodity soybean oil (24% oleic acid, 50% linoleic acid, and 7% linolenic acid), high‐oleic soybean oil (75% oleic acid, 8% linoleic acid, and 2.5% linolenic acid), and linseed oil (11% oleic acid, 15% linoleic acid, and 64% linolenic acid) were each epoxidized to various extents. Epoxidation rate, viscosity, differential calorimetry, and X‐ray diffraction data are presented for these oils and interpreted in the context of their fatty acid profile (mostly oleic, linoleic, or linolenic). While fully epoxidized soybean oil is widely commercially available and used in an increasing array of industrial applications, information relating to partially epoxidized oils and epoxidized oils of other cultivars is less well known. 相似文献
10.
Formation of 4‐Hydroxy‐2‐Trans‐Nonenal,a Toxic Aldehyde,in Thermally Treated Olive and Sunflower Oils
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Jieyao Yuan Don W. Shoeman A. Saari Csallany 《Journal of the American Oil Chemists' Society》2018,95(7):813-823
4‐Hydroxy‐2‐trans‐nonenal (HNE) is a toxic aldehyde produced mostly in oils containing polyunsaturated fatty acid due to heat‐induced lipid peroxidation. The present study examined the effects of the heating time, the degree of unsaturation, and the antioxidant potential on the formation of HNE in two light olive oils (LOO) and two sunflower oils (one high oleic and one regular) at frying temperature. HNE concentrations in these oil samples heated for 0, 1, 3, and 5 hours at 185 °C were measured using high‐performance liquid chromatography. The fatty‐acid distribution and the antioxidant capacity of these four oils were also analyzed. The results showed that all oils had very low HNE concentrations (<0.5 μg g?1 oil) before heating. After 5 hours of heating at 185 °C, HNE concentrations were increased to 17.98, 25.00, 12.51, and 40.00 μg g?1 in the two LOO, high‐oleic sunflower oil (HOSO), and regular sunflower oil (RSO), respectively. Extending the heating time increased HNE formation in all oils tested. It is related to their fatty‐acid distributions and antioxidant capacities. RSO, which contained high levels of linoleic acid (59.60%), a precursor for HNE, was more susceptible to degradation and HNE formation than HOSO and LOO, which contained only 6–8% linoleic acid. 相似文献
11.
Raman Spectroscopic Barcode Use for Differentiation of Vegetable Oils and Determination of Their Major Fatty Acid Composition
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Serap Durakli Velioglu Elif Ercioglu H. Tumay Temiz H. Murat Velioglu Ali Topcu Ismail H. Boyaci 《Journal of the American Oil Chemists' Society》2016,93(5):627-635
In this study, differentiation of vegetable oils and determination of their major fatty acid (FA) composition were performed using Raman spectral barcoding approach. Samples from seven different sources (sunflower, corn, olive, canola, mustard, soybean and palm) were analyzed using Raman spectroscopy. Second derivative of the spectral data was utilized to generate unique barcodes of oils. Chemometric analyses, namely, principal component analysis (PCA) and partial least square (PLS) methods were used for data analysis. PCA was applied for classification of the samples according to the differences in their levels arising from their barcode data. A successful differentiation based on second derivative barcodes of Raman spectra (2D‐BRS) of vegetable oils was obtained. In addition, PLS method was applied on 2D‐BRS in order to determine the major FA composition of these samples. Coefficient of determination values for palmitic, stearic, oleic, linoleic, α‐linolenic, cis‐11 eicosenoic, erucic and nervonic acids were in the range of 0.970–0.989. Limit of detection and limit of quantification values were found to be satisfactory (0.09–8.09 and 0.30–26.95 % in oil) for these fatty acids . Advantages of both chemometric analysis and spectral barcoding approach have been utilized in the present study. Taking the second derivative of the Raman spectra has minimized background variability and sensitivity to intensity fluctuations. Spectral conversion to the barcodes has further increased the quality of information obtained from Raman spectra and also made it possible to improve the visualization of the data. Converting Raman spectra of oils into barcodes enables simpler presentation of the valuable information, and still allows further analysis such as classification of vegetable oils and prediction of their major fatty acids with high accuracy. 相似文献
12.
Vegetable oils have kairomonal attractant properties to grasshoppers primarily due to the presence of linoleic and linolenic
fatty acids. These fatty acids are dietary essentials for grasshoppers and, once volatilized, can be detected by the insects’
olfactory receptors. A laboratory bioassay method has been developed to identify vegetable oils that have fatty acid profiles
similar to grasshoppers and that induce grasshopper attraction and feeding. Such oils could be useful kairomonal adjuvants
and/or carriers for acridicide formulations. Three sets of laboratory bioassays demonstrated that the addition of a standard
aliquot of different vegetable oils resulted in varying degrees of grasshopper feeding on otherwise neutral substrates. Addition
of olive oil stimulated the greatest feeding in all three sets of assays, regardless of the age of the tested insects. Furthermore,
addition of canola or flax oils markedly enhanced grasshopper feeding. These three oils—i.e., olive, canola, and flax oil—proved
to be the best performing grasshopper stimulants. A second group of oils included rapeseed-flax mix and rapeseed oils; however,
their performance was not as consistent as oils in the first group—especially with regard to nymphal feeding. A third group
of oils consisted of soybean, corn, peanut, and sunflower oil. Theoretical expectations regarding these oils varied wildly,
suggesting that the results of a single bioassay should be cautiously interpreted as being negative. 相似文献
13.
14.
T. Mavromoustakos M. Zervou G. Bonas A. Kolocouris P. Petrakis 《Journal of the American Oil Chemists' Society》2000,77(4):405-411
The present study focuses on the olefinic region of the 13C nuclear magnetic resonance (13C NMR) spectrum of virgin olive oil which shows 12 peaks resonating between 127.5 and 130 ppm. These peaks are assigned to
the most abundant unsaturated fatty acid moieties of the olive oil, oleic and linoleic acids, which are present in α and β
positions of the glycerol backbone. With the use of an internal reference pyrazine, the 12 peaks were integrated and their
areas were expressed in mmol/g of virgin olive oil. The intensities of the 12 observed peaks were affected when an authentic
virgin olive oil was mixed with a seed oil. This observation was used to develop a semiquantitative method to detect adulteration
of virgin olive oil by other oils based on 13C NMR spectroscopy. 相似文献
15.
Gozde Gurdeniz Banu Ozen Figen Tokatli 《European Journal of Lipid Science and Technology》2010,112(2):218-226
The composition of olive oils may vary depending on environmental and technological factors. Fatty acid profiles and Fourier‐transform infrared (FT‐IR) spectroscopy data in combination with chemometric methods were used to classify extra‐virgin olive oils according to geographical origin and harvest year. Oils were obtained from 30 different areas of northern and southern parts of the Aegean Region of Turkey for two consecutive harvest years. Fatty acid composition data analyzed with principal component analysis was more successful in distinguishing northern olive oil samples from southern samples compared to spectral data. Both methods have the ability to differentiate olive oil samples with respect to harvest year. Partial least squares (PLS) analysis was also applied to detect a correlation between fatty acid profile and spectral data. Correlation coefficients (R2) of a calibration set for stearic, oleic, linoleic, arachidic and linolenic acids were determined as 0.83, 0.97, 0.97, 0.83 and 0.69, respectively. Fatty acid profiles were very effective in classification of oils with respect to geographic origin and harvest year. On the other hand, FT‐IR spectra in combination with PLS could be a useful and rapid tool for the determination of some of the fatty acids of olive oils. 相似文献
16.
A. L. Amrutha Kala 《Journal of the American Oil Chemists' Society》2012,89(10):1813-1821
The fatty acid composition of 27 samples of commercial hydrogenated vegetable oils and 23 samples of refined oils such as sunflower oil, rice bran oil, soybean oil and RBD palmolein marketed in India were analyzed. Total cis, trans unsaturated fatty acids (TFA) and saturated fatty acids (SFA) were determined. Out of the 27 hydrogenated fats, 11 % had TFA about 1 % where as 11 % had more than 5 % TFA with an average value of about 13.1 %. The 18:1 trans isomers, elaidic acid was the major trans contributor found to have an average value of about 10.8 % among the fats. The unsaturated fatty acids like cis-oleic acid, linoleic acid and α-linolenic acid were in the range of 21.8–40.2, 1.9–12.2, 0.0–0.7 % respectively. Out of the samples, eight fats had fatty acid profiles of low TFA (less than 10 %) and high polyunsaturated fatty acids (PUFA) such as linoleic and α-linolenic acid. They had a maximum TFA content of 7.3 % and PUFA of 11.7 %. Among the samples of refined oils, rice bran oil (5.8 %) and sunflower oil (4.4 %) had the maximum TFA content. RBD palmolein and rice bran oils had maximum saturated fatty acids content of 45.1 and 24.4 % respectively. RBD palmolein had a high monounsaturated fatty acids (MUFA) content of about 43.4 %, sunflower oil had a high linoleic acid content of about 56.1 % and soybean oil had a high α-linolenic acid content of about 5.3 %. 相似文献
17.
Fatty acid composition and its relationship with physicochemical properties of pecan (Carya illinoensis) oil 总被引:1,自引:0,他引:1
J. F. Toro-Vazquez M. A. Charó-Alonso F. Pérez-Briceño 《Journal of the American Oil Chemists' Society》1999,76(8):957-965
The composition and physicochemical properties of pecan (Carya illinoensis) kernels and oils from different native trees of the central region of Mexico were investigated. The main compositional characteristic
of the kernel was the high lipid content (70–79% w/w on dry basis) with elevated concentration of oleic acid (55–75% w/w).
The results confirmed the relationship in the biosynthesis of linoleic and linolenic acids from oleic acid existing in oilseeds.
Our results indicate that in pecans such relationship is a function of pecan tree age. The proportion of oleic, linoleic,
and linolenic fatty acids determined the oxidative stability, viscosity, and melting/crystallization behavior of pecan oil.
In general, these properties in pecan oils were similar or superior to extra-virgin olive oil and unrefined sesame oil. Although
all native pecan oils studied showed a significant concentration of oleic acid, a particular group of native Mexican pecan
trees produces an oil with a fatty acid composition with the nutritional appeal that consumers demand nowadays (i.e., very
high oleic acid, 60–75%), with excellent natural oxidative stability (i.e., induction time for oxidation between 8.5 and 10.8
h), and substantially higher concentrations of α-, γ-, and δ-tocopherol than in pecan varieties previously reported in the
literature. 相似文献
18.
Min-Zhao Huang Shiro Watanabe Tetsuyuki Kobayashi Akito Nagatsu Jinsaku Sakakibara Harumi Okuyama 《Lipids》1997,32(7):745-751
Preliminary experiments have shown that a diet containing 10% rapeseed oil (low-erucic acid) markedly shortens the survival
time of stroke-prone spontaneously hypertensive (SHRSP) rats under 1% NaCl loading as compared with diets containing perilla
oil or soybean oil. High-oleate safflower oil and high-oleate sunflower oil were found to have survival time-shortening activities
comparable to that of rapeseed oil; olive oil had slightly less activity. A mixture was made of soybean oil, perilla oil,
and triolein partially purified from high-oleate sunflower oil to adjust the fatty acid composition to that of rapeseed oil.
The survival time of this triolein/mixed oil group was between those of the rapessed oil and soybean oil groups. When 1% NaCl
was replaced with tap water, the survival time was prolonged by ∼80%. Under these conditions, the rapeseed oil and evening
primrose oil shortened the survival time by ∼40% as compared with n-3 fatty acid-rich perilla and fish oil; lard, soybean
oil, and safflower oil with relatively high n-6/n-3 ratios shortened the survival time by roughly 10%. The observed unusual
survival time-shortening activities of some vegetable oils (rapeseed, high-oleate safflower, high-oleate sunflower, olive,
and evening primrose oil) may not be due to their unique fatty acid compositions, but these results suggest that these vegetable
oils contain factor(s) which are detrimental to SHRSP rats. 相似文献
19.
Rosario Zamora Gemma Gómez M. Carmen Dobarganes Francisco J. Hidalgo 《Journal of the American Oil Chemists' Society》2002,79(3):261-266
One hundred nine oil samples were separated chromatographically to obtain oil fractions with a decreased TAG content but with
enhanced levels of the minor components that define oil genuineness and quality. The oils, which included virgin olive oils
from different cultivars and regions of Europe and north Africa and refined olive, “lampante” olive, refined olive pomace,
hazelnut, rapeseed, high-oleic sunflower, corn, grapeseed, soybean, and sunflower oils, were fractionated on a silica gel
column with hexane/diethyl ether as the mobile phase eluent. The method was highly reproducible, and the fraction obtained
contained about 15% unmodified TAG and 85% polar compounds, which included polymeric TAG, oxidized TAG, DAG, MAG, and FFA,
in addition to other minor polar components of the oils. The presence of these compounds, in an enriched fraction, should
provide information about the thermal, oxidative, and hydrolytic alterations of the oils, as well as many compounds of interest
in determining oil genuineness. The results indicate that these fractions can provide more information than the original oils
for NMR or other spectroscopic studies used in the determination of oil quality. 相似文献
20.
Aslı Yorulmaz Hakan Erinc Aziz Tekin 《Journal of the American Oil Chemists' Society》2013,90(5):647-658
Changes in olive properties and oil quality, oxidative stability, phenolic and chemical composition of two common Turkish varieties (Memecik and Edremit) during maturation were investigated. Olive samples were collected in their own growing region for five different harvest dates and processed to oil with a laboratory scale mill. Metabolic behaviors of these two varieties along with the maturation were different in terms of some compositional parameters. Oleic acid, triolein, β-sitosterol, oleuropein, hydroxytyrosol, and tyrosol contents of olive or olive oils fluctuated with maturation. However, changes in average weight, flesh/pit ratio, water and oil contents of the olives were observed. Phenolics such as trans cinnamic acid contents of both olive fruits decreased whereas cyanidin 3-O-glucoside and cyanidin 3-O-rutinoside anthocyanins increased. Free fatty acids of virgin olive oils were found independent of maturity although some slight changes were determined in peroxide value, dien and trien conjugations. Some compositional parameters such as pigment concentration, tocopherols, stearic acid, linolenic acid, palmitodiolein and monounsaturated/polyunsaturated fatty acid ratio decreased while linoleic acid, dioleolinolein, palmitooleolinolein and Δ-5-avenasterol percentages increased with the maturation. A clear discrimination was observed with principal component analysis. The data obtained can also be considered useful for providing information to determine the ideal maturity stage. 相似文献