Study of the main constituents of some authentic walnut oils

This paper describes the composition of walnut oils obtained from nuts collected from seven countries that are major suppliers of walnut oil. Oils were extracted from the nuts using small-scale industry pressing equipment and analyzed using standard methods for fatty acids, fatty acids in the triacylglycerol 2-position, tocopherols and tocotrienols, triacylglycerols, sterols, steradienes, and iodine value. Values for the composition of the sterols, triacylglycerols, fatty acids, iodine value, and tocopherol composition were generally in good agreement with the results of previous similar surveys. Tocotrienols were not detected in any sample. Steradienes (stigmastadiene, campestadiene, stigmastatriene, and campestatriene) were not detected in any oil.     

Quantitation of the main constituents of some authentic grape-seed oils of different origin

This paper describes the composition of 30 grape-seed oils obtained from France, Italy, and Spain during 2002-2003. Oils were extracted from the seeds using small-scale industrial solvent extraction equipment and analyzed in their unrefined state using standard methods for fatty acids, fatty acids in the triacylglycerol 2-position, tocopherols and tocotrienols, triglycerides, sterols, steradienes, and iodine value. Values for the composition of the sterols, triglycerides, fatty acids, iodine value, and tocopherol composition were generally in good agreement with the results of previous similar surveys. Steradienes (stigmastadiene, campestadiene, stigmastatriene, and campestatriene) were detected in the oil and were probably formed from sterols during the extraction process.     

Quantitation of the main constituents of some authentic sesame seed oils of different origin

This paper describes the composition of sesame seed oils obtained from seeds collected from five countries that are major suppliers of traded sesame seed oil. Oils were extracted from the seeds using small-scale industry pressing equipment and analyzed using standard methods for fatty acids, fatty acids in the triglyceride 2-position, tocopherols and tocotrienols, triglycerides, sterols, steradienes, and iodine value. Values for the composition of the sterols, triglycerides, fatty acids, iodine value, and tocopherol composition were generally in good agreement with the results published elsewhere. All of the oils from roasted seeds contained low levels of the sterol degradation products stigmasta-3,5-diene and campesta-3,5-diene, which were probably formed by dehydration of the parent sterols during roasting.     

Unsaponifiable lipid constituents of some underutilized tropical seed oils

Sterols, triterpene alcohols, and hydrocarbons present in the unsaponifiable fraction of some underutilized tropical seed oils have been examined.The seeds include Telfairia occidentalis (TLO), Andenopus breviflorus (ADB), Cucumeropsis edulis (CME), Antiaris africana (ATF), and Monodora tenuifolia (MNT). The oil content of the seeds was high (34.7-68.8%), whereas triacylglycerols comprised the dominant lipid group in the oils (65.4-73.9%). The percentage of unsaponifiables ranged from 1.1 to 7.9%. Ten sterols were identified in the fractions. In the Cucurbitaceae oils (TLO, CME, and ADB), Delta(7)-sterols constituted the dominant sterols. These include 24-ethylcholesta-7,22E,25-trienol (7), 24-ethylcholesta-7,25-dienol (9), 24Z-ethylidenecholes-7-enol (10), and 24-ethylcholesta-7, 24-dienol (11). However Delta(5)-sterols (1-5) occurred at the highest concentration in the other two samples (ATF and MNT). Fifteeen triterpene alcohols were detected in the fractions. Olean-12-enol (16), isomultiflorenol (8), and lupeol (23) were the dominant alcohols in the Cucurbitaceae family, whereas alpha-amyrin (urs-12-enol) (20) was the dominant triterpene alcohol in ATF and MNT. A mixture of C(18)-C(34) n-alkanes, squalene, and some monoterpenes was detected in the hydrocarbon fraction.     

Rapid quantitative assessment of the adulteration of virgin olive oils with hazelnut oils using Raman spectroscopy and chemometrics

The authentication of extra virgin olive oil and its adulteration with lower-priced oils are serious problems in the olive oil industry. In addition to the obvious effect on producer profits, adulteration can also cause severe health and safety problems. A number of techniques, including chromatographic and spectroscopic methods, have recently been employed to assess the purity of olive oils. In this study Raman spectroscopy together with multivariate and evolutionary computational-based methods have been employed to assess the ability of Raman spectroscopy to discriminate between chemically very closely related oils. Additionally, the levels of hazelnut oils used to adulterate extra virgin olive oil were successfully quantified using partial least squares and genetic programming.     

Solid-phase microextraction for studies on the enantiomeric composition of filbertone in hazelnut oils

The enantiomeric distribution of filbertone was determined in unroasted and roasted hazelnut oils of different geographical origins by using solid-phase microextraction (SPME) and capillary gas chromatography. An optimization procedure including SPME fiber, extraction time, exposure temperature, and sample volume enabled the best conditions to be selected. Under the optimized conditions, detection limits were in the micrograms per liter level for both enantiomers of filbertone with relative standard deviation values of 7.1 and 4.9% for R-filbertone and S-filbertone, respectively. The proposed approach allowed the rapid determination of the enantiomeric composition of filbertone and demonstrated that its variability is an inherent property of the natural compound. Analysis of two batches of hazelnut oils obtained from either unroasted or roasted hazelnuts showed, in general, significantly higher amounts of filbertone in roasted hazelnut oils.     

Repellent activity of essential oils and some of their individual constituents against Tribolium castaneum herbst

A tool for integrated pest management is the use of essential oils (EOs) and plant extracts. In this study, EOs from Tagetes lucida , Lepechinia betonicifolia , Lippia alba , Cananga odorata , and Rosmarinus officinalis , species grown in Colombia, were analyzed by gas chromatography-mass spectrometry. These oils as well as several of their constituents were tested for repellent activity against Tribolium castaneum , using the area preference method. The main components (>10%) found in EOs were methylchavicol, limonene/α-pinene, carvone/limonene, benzyl acetate/linalool/benzyl benzoate, and α-pinene, for T. lucida, L. betonicifolia, L. alba, C. odorata, and R. officinalis, respectively. All EOs were repellent, followed a dose-response relationship, and had bioactivity similar to or better than that of commercial compound IR3535. EOs from C. odorata and L. alba were the most active. Compounds from EOs, such benzyl benzoate, β-myrcene, and carvone, showed good repellent properties. In short, EOs from plants cultivated in Colombia are sources of repellents against T. castaneum.     

Antifungal activity of some essential oils

Thirteen essential oils recovered by steam distillation from Indian herbs were analyzed for their chemical compositions using GC and GCMS. The antifungal activity against plant and Food mold rot were examined in vitro using poison food technique. The essential oil from cymbopogan exhibited control over all the plant and food mold rot tested. The bioactive compound in the oil and its minimum inhibitory concentration were determined using TLC bioautography.     

Antioxidant activities and volatile constituents of various essential oils

Thirteen essential oils were examined for their antioxidant activity using three different assay systems. Jasmine, parsley seed, rose, and ylang-ylang oils inhibited hexanal oxidation by over 95% after 40 days at a level of 500 microg/mL in the aldehyde/carboxylic acid assay. Scavenging abilities of the oils for the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical ranged from 39% for angelica seed oil to 90% for jasmine oil at a level of 200 microg/mL. The greatest inhibitory activity toward malonaldehyde (MA) formation from squalene upon UV-irradiation was obtained from parsley seed oil (inhibitory effect, 67%), followed by rose oil (46%), and celery seed oil (23%) at the level of 500 microg/mL. The main compounds of oils showing high antioxidant activity were limonene (composition, 74.6%) in celery seed, benzyl acetate (22.9%) in jasmine, alpha-pinene (33.7%) in juniper berry, myristicin (44%) in parsley seed, patchouli alcohol (28.8%) in patchouli, citronellol (34.2%) in rose, and germacrene (19.1%) in ylang-ylang.     

Antithrombotic lipid minor constituents from vegetable oils. Comparison between olive oils and others

Many epidemiological studies suggest that vegetable oils and especially olive oil present a protective effect against atherosclerosis. In this study, total lipids (TL) of Greek olive oils and seed oils of four kinds, namely, soybean, corn, sunflower, and sesame oil, were separated into total polar lipids (TPL) and total neutral lipids (TNL) via a novel extraction procedure. TPL and TNL of olive oil were fractionated by HPLC for further study. Each lipid fraction from HPLC separation along with TL, TPL, and TNL lipid samples from oils were tested in vitro for their capacity to induce or to inhibit washed rabbit platelet aggregation. Comparison between olive and seed oils supports the superiority of olive oil as high levels of platelet activating factor (PAF) antagonists have been detected, mainly in TPL. In addition, the structure of the most active fraction from olive oil was elucidated, as a glycerol-glycolipid. Because it has already been reported that PAF plays a pivotal role in atherogenesis, the existence of PAF agonists and antagonists in vegetable oils may explain their protective role against atherosclerosis.     

Characterization of the volatile composition of essential oils of some lamiaceae spices and the antimicrobial and antioxidant activities of the entire oils

The essential oils of Ocimum basilicum L., Origanum vulgare L., and Thymus vulgaris L. were analyzed by means of gas chromatography-mass spectrometry and assayed for their antioxidant and antimicrobial activities. The antioxidant activity was evaluated as a free radical scavenging capacity (RSC), together with effects on lipid peroxidation (LP). RSC was assessed measuring the scavenging activity of the essential oils on 2,2-diphenyl-1-picrylhydrazil (DPPH(*)) and OH(*) radicals. Effects on LP were evaluated following the activities of essential oils in Fe(2+)/ascorbate and Fe(2+)/H(2)O(2) systems of induction. Essential oils exhibited very strong RSCs, reducing the DPPH radical formation (IC(50)) in the range from 0.17 (oregano) to 0.39 microg/mL (basil). The essential oil of T. vulgaris exhibited the highest OH radical scavenging activity, although none of the examined essential oils reached 50% of neutralization (IC(50)). All of the tested essential oils strongly inhibited LP, induced either by Fe(2+)/ascorbate or by Fe(2+)/H(2)O(2). The antimicrobial activity was tested against 13 bacterial strains and six fungi. The most effective antibacterial activity was expressed by the essential oil of oregano, even on multiresistant strains of Pseudomonas aeruginosa and Escherichia coli. A significant rate of antifungal activity of all of the examined essential oils was also exhibited.     

Chemical constituents in Baccharis dracunculifolia as the main botanical origin of southeastern Brazilian propolis

Previously, it was reported that one group of propolis (Group 12) was identified in southeastern Brazil, and the botanical origin of the propolis was Baccharis dracunculifolia resinous exudates. It was also observed that honeybee (Africanized Apis mellifera) mainly visited the leaf buds or unexpanded leaves of B. dracunculifolia but rarely expanded leaves. B. dracunculifolia is dioecious with male and female inflorescences, and RPHPLC of the ethanolic extracts of the respective male and female bud resinous exudates showed the same profiles. RPHPLC profiles of propolis G12 leaf buds and unexpanded and expanded leaves of B. dracunculifolia showed similarity, but unexpanded leaves quantitatively decreased in chemical constituents as compared with leaf buds. In the case of expanded leaves, all chemical constituents were severely decreased or disappeared. Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) was also identified in both propolis and resinous exudates, and both ethanolic extracts contained the highest concentrations of this compound as compared with the rest of the chemical constituents.     

Polyphenolic composition of hazelnut skin

Skins from different hazelnut samples were characterized for total polyphenol content, total antioxidant capacity (TAC), and their content in specific polyphenolic compounds. The main polyphenolic subclass, identified and quantified by means of HPLC-MS/MS, comprised monomeric and oligomeric flavan-3-ols, which accounted for more than 95% of total polyphenols. Flavonols and dihydrochalcones were 3.5% while phenolic acids were less than 1% of the total identified phenolics. The TAC values of the skin samples ranged between 0.6 and 2.2 mol of reduced iron/kg of sample, which is about 3 times the TAC of whole walnuts, 7-8 times that of dark chocolate, 10 times that of espresso coffee, and 25 times that of blackberries. By describing the profile of polyphenols present in hazelnut skins, this study provides the basis to further investigate the potential health effects of hazelnut byproduct.     

分提橄榄油中主要脂肪酸成分傅里叶变换红外光谱法测量（英）

为了测量从橄榄油中分提的高、低熔点油脂的脂肪酸成分,在4 000～600 cm-1 的范围测量了31个含有不同脂肪酸成分植物油的傅里叶变换红外光谱,用于建立偏最小二乘（PLS）回归分析校正模型。在油脂的傅里叶变换红外光谱变量和脂肪酸组成变量之间建立了交叉验证的PLS校正模型。为了校正油酸和亚油酸含量,在4?000～600 cm-1 的频率范围,经平滑,二阶导数,规范化处理的红外光谱获得了最好的交叉验证校正模型和最佳的预测结果。PLS校正模型预测结果表明,与高熔点橄榄油（油酸,72.29%,亚油酸,9.98%）相比,低熔点橄榄油含有较高的油酸含量和亚油酸含量（油酸,77.46%,亚油酸,12.51%）,预测的结果与气相色谱测量的结果有很好的一致性。建立的PLS校正模型预测橄榄油的不饱和脂肪酸含量具有较好的相关性。该研究为分提油脂质量的判别评价提供了便捷的方法。     

In vivo antioxidant activities of essential oils and their constituents from leaves of the Taiwanese Cinnamomum osmophloeum

Cinnamomum osmophloeum Kaneh is an indigenous tree species in Taiwan. In this study, phytochemical characteristics and antioxidant activities of the essential oils and key constituents from the leaves of two C. osmophloeum clones were investigated. The two trees possess two chemotypes, which were classified as the cinnamaldehyde type and camphor type. We demonstrated that the essential oils from C. osmophloeum leaves exerted in vivo antioxidant activities in Caenorhabditis elegans. In addition, trans-cinnamaldehyde and D-(+)-camphor, which respectively represent the major compounds in the cinnamaldehyde-type and camphor-type trees, exerted significant in vivo antioxidant activities against juglone-induced oxidative stress in C. elegans. Moreover, expressions of antioxidative-related genes, including superoxide dismutase (SOD) and glutathione S-transferase (GST), were significantly induced by trans-cinnamaldehyde and D-(+)-camphor from C. osmophloeum leaves. Our results showed that the essential oils from C. osmophloeum leaves and their major compounds might have good potential for further development as nutraceuticals or antioxidant remedies.     

Titrimetric determination of iodine-bromine numbers of some edible oils using three N-chloroimides

Three simple titrimetric methods have been developed to determine iodine-bromine numbers of some edible oils, such as coconut, gingelly, groundnut, mustard, olive, palm olein, and sunflower, using 3 N-chloroimides. The 3 N-chloroimides are N-chlorophthalimide, N-chlorosuccinimide, and N-chlorosaccharin, all of which have recently been developed as potential oxidimetric titrants for use in aqueous acetic acid medium. The proposed excess back-titration methods have advantages over existing methods in terms of ease of extraction into aqueous acetic acid layer, shorter reaction time of NCSA method, and stability of N-chloroimides in solid state.     

Effects of roasting on hazelnut lipids

The effect of roasting on some nutritional characteristics of hazelnut lipidic fraction was investigated. Hazelnuts (Corylus avellana L.) were submitted to several different thermal treatments, comprising different temperatures (125-200 degrees C) and times of exposure (5, 15, and 30 min) and analyzed for their moisture and crude fat. Raw and roasted hazelnuts were also analyzed for their compositions in phytosterols and fatty acids (including trans isomers) by GC-FID, triacylglycerols by HPLC-ELSD, and tocopherols and tocotrienols by HPLC-DAD/fluorescence spectroscopy. Minor changes occurred in the fatty acid and triacylglycerol compositions. As temperatures and roasting periods increased, generally, a modest increase of oleic and saturated fatty acids and a decrease of linoleic acid, expressed as relative percentages, occurred. Similarly, an increase of triacylglycerols containing oleic acid moieties and a decrease of those containing linoleic acid moieties were found in the roasted samples. Roasting caused a modest decrease of the beneficial phytosterols (maximum 14.4%) and vitamin E homologues (maximum 10.0%) and a negligible increase of the trans fatty acids.     

Determination of the diglyceride content in greek virgin olive oils and some commercial olive oils by employing (31)P NMR spectroscopy

In this study, the diglyceride contents of 96 samples of virgin olive oils from the regions of Crete, Lesvos, Messinia, Pilion, Zakynthos, Halkidiki, and Ilia, 15 samples of commercial extra virgin and pure olive oils, and 3 samples each of refined olive oils and pomace oils were determined by a facile method introduced in a previous publication. This method is based on the phosphitylation of the free hydroxyls of the diglycerides with 2-chloro-4,4,5,5-tetramethyldioxaphospholane and the integration of the appropriate peaks in the (31)P NMR spectra. This preliminary study showed interesting trends in the diglyceride content of the virgin olive oils from the various regions of Greece that can be used as simple criteria to assess the olive oil characteristics. Analysis of variance has been carried out for the diglyceride content of each region in an attempt to detect possible differences in the diglyceride levels among the various regions. Finally, the relationship between the ratio of 1,2-diglycerides to the total amount of diglycerides and the total amount of diglycerides has been used to monitor the quality of virgin olive oils, commercial olive oils, refined olive oils, and pomace oils.