The Contents of Lignans in Sesame Seeds and Commercial Sesame Oils of China

In this study, the concentrations of three lignans in 100 sesame seeds and 56 sesame oils were determined using a newly developed method based on high‐performance liquid chromatography coupled with a UV/Vis detector. Total lignan contents in sesame seed and oil samples ranged from 2.52 to 12.76 and 3.38 to 11.53 mg/g, respectively. Black sesame seeds showed higher sesamin content (range 1.98–9.41 mg/g, mean 4.34 mg/g) and sesamolin content (range 1.06–3.35 mg/g, mean 1.92 mg/g) than the other three varieties of sesame seeds. Black sesame oils had higher contents of lignans than the white sesame oils, although remarkable differences were not observed. Hot pressed and small mill sesame oils expressed higher contents of sesamol, sesamin, and total lignans than the cold pressed and refined sesame oils. The results revealed that there is extensive variability in lignan concentration in sesame oils and seeds.     

The comparison of properties of the oil and kernels of various hazelnuts from Germany and Turkey

The oil yields of hazelnut kernels collected from Germany (Münster) and Turkey range from 8.1 to 64.1%. The main fatty acids in hazelnut kernel oils are oleic (76.3–82.6%), linoleic (6.5–14.0%), and palmitic (5.7–6.5%). The hazelnut kernel oils contained an appreciable amount of α‐tocopherol (19.9–63.9 mg/100 g), with a mean value of 40.02 mg/kg, and γ‐tocopherol (1.3–15.5 mg/100 g), with a mean value of 4.84. α‐Tocopherol was the predominant tocopherol in all hazelnut kernels. The major sterols were β‐sitosterol, ranging from 78.13 to 82.56 mg/kg; campesterol, ranging from 4.79 to 7.42 mg/kg; and δ5‐avanasterol, ranging from 1.26 to 5.24 mg/kg. The highest minerals were K and P followed by Ca, Mg, Na, and Zn. P contents of all samples were established between 2029.90 and 4376.66 ppm. The results may also be useful for the evaluation of nutritional information. As a result, the present study showed that the kernels of hazelnut are a potential source of valuable oil which might be used for food and non‐food applications. In addition, hazelnut kernel oil has a high nutritive value and can be recommended for processing of healthy food products.     

Phytosterols in 17 Turkish hazelnut (Corylus avellana L.) cultivars

The phytosterol contents of the oils from 17 Turkish hazelnut cultivars were determined by gas chromatography with a flame ionization detector. The total phytosterol content varied from 1180.4 (Uzunmusa‐Ordu) to 2239.4 mg/kg (Cavcava), and the average was 1581.6 ± 265.1 mg/kg. One of the most significant commercial cultivars, Tombul, contained quite low total phytosterols (1297.7 mg/kg). Total and individual phytosterol contents of hazelnut cultivars were significantly different at p <0.01, except for phytostanol and campestanol. The main component was β‐sitosterol which ranged from 82.8 to 86.7% in all cultivars. This was followed by campesterol, Δ⁵‐avenasterol, sitostanol and stigmasterol. Interestingly, the same cultivars from different regions showed similar total phytosterol contents, and fall almost within the same range according to Duncan's test, which may indicate that the phytosterol content is highly related to the cultivar.     

Supercritical fluid extraction and characterisation of oil from hazelnut

Hazelnut (Corylus avellana L.) oil was extracted with compressed carbon dioxide in the temperature range of 308—321 K and in the pressure range of 18—23.4 MPa. In addition the influence of the superficial velocity, within a tubular extractor was studied. Physical and chemical characteristics of the oil were obtained. The results including contents of free fatty acids, sterols, triacylglycerols and tocopherols were compared with those obtained when n‐hexane was used as solvent. No significant differences were found when the oils extracted by both methods were analysed. The main fatty acid was the oleic acid (83—85%), followed by linoleic acid (6—8%) and palmitic acid (5—6%). The main triglyceride found in hazelnut oils was the trioleylglycerol (OOO) (63.4—69.6%), followed by the linoleyl‐dioleylglycerol (LOO) (11.6—15.5%) and palmitoyl‐dioleylglycerol (POO) (9.9—10.4%). In terms of sterols, the main component was β‐sitos‐terol (∼83%) followed by campesterol (∼6%). The amount of cholesterol was very low (∼0.2%). The CO₂ extracted oil contained about 17% more tocopherols (458.7 μg/g oil) than the oil extracted by n‐hexane (382.8 μg/g). Oxidative stability was studied by using the induction time determined by the Rancimat method. The oil obtained by supercritical fluid extraction (SFE) was slightly more protected against oxidation (8.7 h for SFE extracted oil and 6.7 h for the hazelnut oil extracted with n‐hexane). Both oils presented high stability index values (7.81 for the oil extracted by n‐hexane and 8.7 for the oil extracted with supercritical CO₂). Oil extracted by supercritical CO₂ was clearer than the one extracted by n‐hexane, showing some refining. Besides, the acidity index was 1.6 for the n‐hexane extracted oil and 0.9 for the oil extracted with supercritical carbon dioxide. The central composite non‐factorial design was used to optimise the extraction conditions, using the Statistica, version 5 software (Statsoft). The best results, in terms of recoveries of hazelnut oil by SFE, were found at 22.5 MPa, 308 K and superficial velocity of 6.0 × 10^—4 ms^—1.     

Effects of Variety,Maturation and Growing Region on Chemical Properties,Fatty Acid and Sterol Compositions of Virgin Olive Oils

Chemical properties, fatty acid and sterol compositions of olive oils extracted from Gemlik and Halhal? varieties grown in Hatay and Mardin provinces in Turkey were investigated during four maturation stages. The olive oil samples were analyzed for their chemical properties such as free acidity, peroxide value, total carotenoid, total chlorophyll, total phenolic contents, antioxidant activity, fatty acid and sterol compositions. Chemical properties, fatty acids and sterol profiles of olive oil samples generally showed statistically significant differences depending on the varieties, maturation and growing areas (p < 0.05). As free fatty acid contents and total phenolic contents increased, total carotenoid and chlorophyll contents decreased throughout the maturity stages. Total carotenoid and chlorophyll contents of oil samples from Mardin were higher than those of Hatay. The total phenolic compounds of olive oil samples ranged from 20.62 in Gemlik to 525.22 mg GAE/kg oil in Halhal? from Hatay. In general, the phenolic contents and antioxidant activities of olive oil samples were positively associated. Oleic acid content was the highest 71.53 % in H1 samples in Hatay. Total sterol contents were 1194.33 mg/kg in Halhal? and 2008.66 mg/kg in Gemlik from Hatay. Stigmasterol contents of oils obtained from Hatay were lower than those of Mardin. Oleic acid, palmitic acid, β‐sitosterol, ?‐5‐avenasterol and campesterol contents fluctuated with maturation for each of variety from both growing regions. These results showed that the variety, growing area and maturation influence the chemical properties, fatty acid and sterol compositions.     

Chemical characteristics of oils from naked and husk seeds of Cucurbita pepo L.

Pumpkin seed oils from naked and husk pumpkin seeds, produced by an industrial process and by laboratory extraction, were evaluated for fatty acid composition, tocopherol, sterol and squalene content. The major fatty acids in the oils from both varieties were oleic, linoleic and palmitic acid, followed by stearic acid. The ratios of monounsaturated to polyunsaturated fatty acids for husk and naked seed oils were about 0.60 and 0.75, respectively. Analysis of tocopherols in industrially pressed and laboratory‐extracted oils showed that husk seed oils had higher amounts of total tocopherols than naked seed oils. Oils extracted in the laboratory had higher amounts of tocopherols than industrial oils. Pumpkin seed oil, in general, had a high level of squalene, which was higher in husk seed oils than in naked seed oils and in extracted than in pressed oils. The total amount of sterols was higher in husk than in naked seed oils and in extracted oil samples. The main sterols were Δ7‐sterols and their content was similar in all samples, but the content of Δ5‐sterols was higher in oil samples of husk pumpkin seed and in extracted than in pressed oils.     

Determination of polyphenols,tocopherols, and antioxidant capacity in virgin argan oil (Argania spinosa,Skeels)

This study establishes data on polyphenols, tocopherols, and antioxidant capacity (AC) of virgin argan oil. A total of 22 samples from Morocco were analyzed. Total polyphenol content ranged between 6.07 and 152.04 mg GAE/kg. Total tocopherols varied between 427.0 and 654.0 mg/kg, being γ‐tocopherol the major fraction (84.68%); α‐, β‐, and δ‐tocopherols represent 7.75, 0.33, and 7.29%, respectively. No influence of oil extraction method on total tocopherols was observed. The AC of argan virgin oils determined by the ABTS method in n‐hexane oils dilution ranged between 14.16 and 28.02 mmol Trolox/kg, and by the ABTS, DPPH, and FRAP methods in methanolic oil extracts between 2.31–14.15, 0.19–0.87, and 0.62–2.32 mmol Trolox/kg, respectively. A high correlation was found between ABTS and DPPH methods applied to a methanolic oil extract. Virgin argan oil presents a higher polyphenol and tocopherol content, and total AC than other edible vegetable oils.     

Bioactive compounds in unsaponifiable fraction of oils from unconventional sources

The aim of the research was to characterize bioactive components of unsaponifiable fraction of selected unconventional oils. Nine oils were analyzed as far as the content of tocopherols, squalene, phenolic compounds, and sterols were concerned. Tocopherols and squalene were analyzed by HPLC coupled with diode array detector and fluorescent detector (HPLC‐DAD‐FLD). The content of sterols in oils was determined by GC coupled with MS (GC‐MS). The total amount of phenolic compounds in oils was determined by the colorimetric methods using Folin–Ciocalteau phenol reagent. The examined oils were characterized by differentiated amount of particular forms of tocopherols. The oil obtained from the seeds of amaranth was the richest source of squalene (over 52 mg/g oil). The presence of 22 different compounds of sterols were identified, whereas β‐sitosterol was found in the largest amount. Total amount of sterols in the oils ranged from 90 (walnut) to 850 mg/100 g (evening primrose). Significant differentiation of total amount of phenolic compounds was observed in the examined oils. Evening primrose oil showed the highest amount of phenolic compounds (679 mg/kg). The presented results prove that plant oils obtained from nonconventional sources are a potential source of bioactive compounds.     

Biochemical Characterization of Arbequina Extra Virgin Olive Oil Produced in Turkey

Varieties of the olive cultivar Arbequina have recently been cultivated in Turkey. The objective of the study is to characterize and evaluate extra‐virgin olive oils (EVOO) produced from Arbequina grown in the Aegean and Mediterranean regions of Turkey. Major and minor components such as carotenoids, squalene, phenolics and tocopherols were studied to assess their effects on product quality and health benefits. The samples, identified as ArbqI and ArbqA, were from the Izmir and Adana provinces, respectively. Samples were analyzed by GC‐FID to determine fatty acid composition, sterol composition, TAG profile and squalene content. Individual phenolic fractions were analyzed by LC–MS/MS and tocopherol isomers were determined by HPLC. According to the results obtained from this study; Total phenolic content (TPC) of the samples were 454.68 and 50.86 mg Gallic acid/kg oil for ArbqI and ArbqA, respectively. Hydroxytyrosol and tyrosol were determined to be the main phenols. The major tocopherol isomer found in ArbqI and ArbqA was α‐tocopherol with levels of 179.55 and 202.5 mg/kg oil, respectively. β‐Carotene levels in both samples were similar at 0.2 mg/kg. Findings of this study were compared with the literature on Arbequina olive oil produced in different countries. It was determined that Arbequina olive oil of high quality can be produced in Turkey, especially in the Aegean region.     

Characterization of oils of hazelnuts from Asturias,Spain

Nine varieties of virgin hazelnut oil from different autochthonous cultivars from distinct locations in Asturias (Spain) were obtained by extraction under a pressure of 280 kg/cm² at a temperature of 45 °C. The extracted oils were separated and filtered. The overall composition (percentages of husk, oil and moisture) of unhusked seeds was determined as well as moisture, ash, total sulfur and heat power of the husks for their possible use as biomass. Recovery of the oil extraction procedure for its application to the production of extra virgin edible hazelnut oil was studied. Fatty acid, tocopherol and sterol compositions as determined by capillary column gas chromatography and triglyceride compositions as determined by high performance liquid chromatography are reported in this study. All values were compared with a Turkish and a French hazelnut oil, with solvent‐extracted hazelnut oil and with a 75/25 blend. A cluster analysis was performed as a criterion to differentiate the different hazelnut oils as groups.     

Analysis of carotenoids and vitamin E in selected oilseeds,press cakes and oils

Carotenoids and vitamin E in oils from the market – 6 rapeseed and 6 sunflower oils, half of each cold pressed and refined – and in the oils of rape, sunflower, flax and safflower as well as the respective seeds and press cakes from a local oil mill were quantified by HPLC. Furthermore, a photometric determination of carotenoid content was tested and checked against the chromatographic method. In the cold pressed oils minor amounts of xanthophylls (all‐E)‐lutein and (all‐E)‐zeaxanthin were determined. With exception of traces of (all‐E)‐β‐carotene in cold‐pressed rapeseed oil this provitamin A active compound did not occur. Cold pressed rapeseed oils contained 0.5–1.5 mg total carotenoids/100 g which was manifold the content of the further oils. Vitamin E was found in all vegetable oils at plant‐typic tocopherol patterns. The photometric determination of carotenoids resulted in significantly higher concentrations compared to the HPLC. This overestimation bases on the carotenoid pattern which was validated by comparison with known high‐carotenoid materials, i.e. maize flour with an abundant amount of xanthophylls and carrots with an abundant amount of carotenes.     

Chemical evaluation of some paprika (Capsicum annuum L.) seed oils

The oil contents of seeds from paprika (Capsicum annuum L.) collected from different locations in Turkey and Italy varied in a relatively wide range from 8.5 g/100 g to 32.6 g/100 g. The fatty acid, tocopherol and sterol contents of the oils from different paprika seeds were investigated. The main fatty acids in paprika seed oils were linoleic acid (69.5–74.7 g/100 g), oleic acid (8.9–12.5 g/100 g) and palmitic acid (10.7–14.2 g/100 g). The oils contained an appreciable amount of γ‐tocopherol (306.6–602.6 mg/kg), followed by α‐tocopherol (7.3–148.7 mg/kg). The major sterols were β‐sitosterol (1571.4–4061.7 mg/kg), campesterol (490.8–1182.7 mg/kg), and Δ⁵‐avenasterol (374.5–899.6 mg/kg). The total concentration of sterols ranged from 3134.0 mg/kg to 7233.7 mg/kg. Remarkable amounts of cholesterol were found in the different samples (164.6–491.0 mg/kg). The present study showed that paprika seeds are a potential source of valuable oil that could be used for edible and industrial applications.     

Chemical Composition and Physical Properties of High Oleic Safflower Oils (Carthamus tinctorius,Var. CW88-OL and CW99-OL)

Chemical composition and physical properties of CW88‐OL and CW99‐OL cultivars of high oleic safflower seeds and their hexane‐extracted oils were determined. Dry‐based seed composition of CW88‐OL and CW99‐OL was: moisture = 4.29 and 4.23 %, oil = 42.29 and 46.44 %, Crude protein = 20.94 and 16.41 %, neutral detergent fiber = 28.11 and 28.49 %, ash = 1.55 and 2.01 %, phosphorus content = 2033 and 3995 mg/kg, respectively. Major fatty acids in oils were ~78 % oleic (O), ~13 % linoleic (L), ~5 % palmitic (P) and ~2 % stearic (St) acids, for both cultivars. The main triacylglycerols were OOO (~50 %), OOL (~20 %), SOL + OPO (~10 %), and LLP (~5 %). The oil composition of CW88‐OL and CW99‐OL in main minor components was: α‐tocopherol = 582 and 551 mg/kg, total sterols = 3996 and 3362 mg/kg, phospholipids = 22 and 21 mg/kg and wax content = 70 and 74 mg/kg. For both cultivars, density and viscosity of the oils between 25 and 55 °C varied from 903.4 to 912.6 kg/m³ and 63 to 23 mPa.s showing linear and exponential behaviors, respectively. The refractive index was 1.4694. The CIELab color parameters were: 89.69 and 89.53 (L*), ?3.72 and ?3.07 (a*), and 47.28 and 47.78 (b*) (CW88‐OL and CW99‐OL, respectively). Thus, the high oil content of the seeds and nutritional quality of the oil accompanied by low levels of waxes and phospholipids makes the cultivars studied promising for producers and consumers.     

Evaluation of Castor Oil Samples for Potential Toxin Contamination

Castor oil and its derivatives are widely used as a chemical feedstock for production of lubricants and greases, engineering plastics, plasticizers and surfactants. It also has wide application in consumer goods such as lipstick, deodorants and medicinal uses. Due to concerns about the possible presence of the ricin toxin in the oil, we have tested a collection of castor oils processed using different approaches, including cold‐pressed, US Pharmaceutical (USP) grade, and neutralized oils. Water soluble proteins were extracted from oil samples into phosphate‐buffered saline containing 0.05 % bovine serum albumin (PBSB) and analyzed for potential ricin contamination by ELISA. Our results indicate that only the cold‐pressed castor oil contained measurable levels of the toxin, estimated to be 35 ± 13 μg/l. A normal oral dose of castor oil for laxative use is 14 ml, so even cold‐pressed castor oil would be well below the toxic level of 1–5 μg/kg body weight. However, the presence of the toxin indicates that other soluble proteins, including allergens, may be present in cold‐pressed castor oil.     

Effect of Oils Extracted from Plant Seeds on the Growth and Lipolytic Activity of <Emphasis Type="Italic">Yarrowia lipolytica</Emphasis> Yeast

This study was aimed at evaluating the capability of Yarrowia lipolytica W29 for the synthesis of lipolytic enzymes in a medium containing plant oils from non‐conventional sources with some components displaying bioactivity. Oils from almond, hazelnut, and coriander seeds were obtained by using n‐hexane (Soxhlet method) and a chloroform/methanol mixture of solvents (Folch method), and their effect on the growth and lipolytic activity of Y. lipolytica was compared. A comparison of these two extraction methods showed that the extraction with n‐hexane was less effective regarding the oil extraction yields than the extraction conducted according to Folch's procedure. The lipolytic activity of the studied yeast was higher in the culture media containing oils extracted with the Soxhlet method than the Folch method but it was lower compared to olive oil medium. Among all oils tested, almond oil extracted with n‐hexane was the best inducer of extracellular lipases synthesized by Y. lipolytica. Its lipolytic activity achieved the maximum value of 2.33 U/mL after 48 h of culture. After 24 h of culture, it was close to the value obtained for the medium containing olive oil. Almond oil was a source of oleic and linoleic acids, which may determine differences in the lipolytic activity. The linoleic acid content in almond oil was higher than that found in other oils. When n‐hexane was used for extraction, the resultant oils were characterized by lower contents of polyphenols and poorer antioxidative activity.     

Comparison of supercritical CO2 and hexane extraction of lipids from sorghum distillers grains

Total yields and compositions of sorghum dried distillers grains with solubles (DDGS) lipids obtained by supercritical CO₂ (SC‐CO₂) extraction were compared with those obtained by recirculated solvent extraction (RSE) with hexane. The total yield of lipids obtained by SC‐CO₂ extraction at 27.5 MPa and 70 °C was 150 g lipids/kg DDGS, while the yield obtained by RSE with hexane at 69 °C was only 85 g lipids/kg DDGS. The contents of four high‐value compounds, i.e., policosanols, phytosterols, free fatty acids (FFA) and tocols, in the lipids obtained by SC‐CO₂ extraction were 31.2, 15.6, 155.3 and 0.50 mg/g at 27.5 MPa and 70 °C, compared to 26.6, 9.6, 57.3 and 0.03 mg/g for RSE with hexane at 69 °C. The profiles of phytosterols and FFA in the sorghum DDGS lipids were relatively independent of the extraction methods and operating conditions.     

The determination of light petroleum residues in refined oils and fats

A rapid, direct injection gas liquid chromatographic (GLC) method for determining residual light petroleum in edible vegetable oils has been developed. The response is linear at levels between 0.05–0.5 mg hexane/kg oil. A sample containing 0.2 mg hexane/kg oil was analyzed for repeatability, giving a standard deviation of 0.008 mg/kg, equivalent to a coefficient of variation of 4%. Separation of pentane, hexane, heptane, octane and decane was obtained by this method. A survey of 23 samples of freshly refined vegetable oils obtained from 13 U.K. refiners in 1981 showed that these all contained less than 0.05 mg hexane/kg oil.     

Bioactive Compounds in Virgin Olive Oil of the PDO Montoro-Adamuz

Virgin olive oil (VOO) is generally recognized as a healthy fat because of its fatty acid composition and content in minor compounds but a wide range of these substances can be found in commercial oils. The concentration of compounds with attributed health benefits were analyzed in VOO of the PDO Montoro‐Adamuz. Oleic acid represented around 79 % of the total fatty acids, and the mean squalene and tocopherols concentrations were 5800 and 247 mg/kg respectively. Despite the changes found in polyphenols concentration in the oils analyzed for six consecutive crops, these substances accounted for more than 700 mg/kg. Moreover, the effect of irrigation regime and sun radiation on the content in bioactive substances of these oils was also assessed. No significant differences were detected between oils from trees irrigated ad libitum or rain‐feed. In contrast, the level of tree radiation exerted a great effect on the concentration of bioactive substances in oils. Oils from trees cultivated in a sunny area (south orientation) had a higher percentage of oleic acid and concentration in phenolic compounds than those from shady areas (north orientation). The opposite was detected for tocopherols and squalene which were more concentrated in oils from olives of the shady area. The results obtained in this study point out VOO of the PDO Montoro‐Adamuz as a very healthy fat due to their composition in bioactive substances, in particular their richness in phenolic compounds.     

Antioxidant (Tocopherol and Canolol) Content in Rapeseed Oil Obtained from Roasted Yellow-Seeded <Emphasis Type="Italic">Brassica napus</Emphasis>

In this study, the effect of temperature (140, 160, 180 °C) and roasting time (5, 10, 15 min) on the bioactive compound content (canolol, tocopherol and plastochromanol‐8) of cold‐pressed oil from yellow‐seeded rapeseed lines of different colors was investigated. Roasting increased the peroxide value in the seed oils compared to the oils from the control samples. However, roasting did not affect the acid values of the oils, which were 1.15–1.47 and 1.30–1.40 mg KOH/g, for line PN1 03/1i/14 (yellow seeds) and line PN1 563/1i/14 (brown seeds), respectively. In this study, the seeds of line PN1 03/1i/14 were characterized by different changes in canolol content during roasting than the seeds of PN1 563/1i/14. There was a 90‐fold increase in canolol for the line PN1 03/1i/14 (768.26 µg/g) and a 46‐fold increase for the line PN1 563/1i/14 (576.43 µg/g). Changes in tocopherol and PC‐8 contents were also observed. There was an increase in the contents of γ‐T and PC‐8 in the oils obtained from the seeds roasted at 180 °C for 10 and 15 min. γ‐T content increased by 17–18% after 15 min of roasting, whereas the PC‐8 content increased twofold.     

Detection of pressed hazelnut oil in admixtures with virgin olive oil by analysis of polar components

Analysis of the polar fraction from virgin olive oil and pressed hazelnut oil by high-performance liquid chromatography showed marked differences in the chromatograms of the polar components in the two oils. Six commercial samples of pressed hazelnut oil and 12 samples of virgin olive oil (or blended olive oil including virgin olive oil) were analyzed. The phenolic content of the pressed hazelnut oil samples was 161±6 mg·kg⁻¹. Inspection of the chromatograms showed that the pressed hazelnut oil extracts contained a component that eluted in a region of the chromatogram that was clear in the olive oil samples, and consequently this component could be used to detect adulteration of virgin olive oil by pressed hazelnut oil. The component had a relative retention time of 0.9 relative to 4-hydroxybenzoic acid added to the oil as an internal standard. The ultraviolet spectrum of the component showed a maximum at 293.8 nm, but the component could not be identified. Analysis of blends of oils showed that adulteration of virgin olive oil by commercial pressed hazelnut oil could be detected at a level of about 2.5%.