Isomere Monoensäuren in Pflanzenölen

Isomeric Monoenoic Acids in Vegetable Oils In the scope of systematic studies the fatty acids of oils from seed and fruits of 38 plants are investigated for presence of isomeric monoenoic acids with 16, 18 and 20 C-atoms. All analyzed oils contain between 2 and 4 hexadecenoic, octadecenoic and icosenoic acids with different position of the double bound. Vaccenic acid, the cis-11-octadecenoic acid, is always found in low quantities. Its share depends within certain limits on the content of the oils of cis-9-hexadecenoic acid, the so-called palmitoleic acid. Petroselinic acid, cis-6-octadecenoic acid, is found in apiaceae oils and also in the seed oil of some other plant families. Besides, 14 of the investigated oils contain low quantities of ω5-monoenoic acids.     

木本油料脂肪酸组成、提纯及其应用研究进展

木本油料是我国传统工业油料,应用领域广泛,可作为优质的食用植物油的来源,也可作为生产生物柴油的原料,并且还被用于饲料添加剂和化妆品行业。木本油料中C12~C18不饱和脂肪酸含量高,易被人体吸收,不同提取技术(压榨法、水酶法、超声波辅助法、浸出法等)对木本油料的脂肪酸组成及含量的影响较小。本文对橡胶籽油、核桃油、椰子油、山苍子核仁油、牡丹籽油、油茶籽油和棕榈油等7种木本油料的资源量、应用情况做了简单介绍,并综述了7种木本油料的脂肪酸组成及其提取纯化技术,重点介绍了木本油料中的中长碳链不饱和脂肪酸的提纯技术,并对提纯后的月桂酸、油酸、亚油酸、亚麻酸的应用进行了综述和展望。     

Evaluation of the Triglyceride Composition of Pomegranate Seed Oil by RP‐HPLC Followed by GC‐MS

Triglyceride composition and fatty acid profiles of pomegranate seed oil were evaluated by newly developed methods in reverse‐phase‐high performance liquid chromatography (RP‐HPLC) and gas chromatography (GC), respectively. Different compositions of the mobile phase (acetone and acetonitrile) and flow rates for the HPLC system were used to obtain better separation for accurate quantitative analysis. Triglycerides with conjugated fatty acids (CLnAs) were eluted in order of the polarity of their geometrical isomers (c, t, c < t, t, c < t, t, t). The dominant triglyceride was found to be PuPuPu (32.99 %) in pomegranate seed oil, followed by PuPuCa and PuCaCa containing punicic acid and catalpic acid with total triglyceridelevels of 27.72 and 10.11 %, respectively. For fatty acid composition analysis, triglyceride fractions were derivatized into their respective methylesters which were injected into gas chromatography‐mass spectrometry (GC‐MS) to identify and gas chromatography‐flame ionization detector (GC‐FID) to quantify the conjugated fatty acids of each fraction of triglycerides. Punicic acid was found to be dominant (76.57 %) followed by catalpic acid (6.47 %) and β‐eleotearic acid (1.45 %). Pomegranate seed contained greater amounts of conjugated linolenic acids. These results showed that the present study provides more information about the composition of the triglyceride and fatty acid profiles of pomegranate seed oil compared to the reported studies. Therefore, the developed methods in this study can be used for the identification of the triglyceride and fatty acid composition for pomegranate seed oils and some such specials edible oils including CLnA isomers.     

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.     

Lipidchemical Investigation of Some Oilplants for Edible Oil Production Cultivated in Mongolia

Seeds of some oilplants cultivated in Mongolia (rapeseed, sunflower, soya and mustard) were investigated for oil content and fatty acid composition in dependence of their varieties and cultivation regions. Seeds of given oilplant varieties have nearly same fatty acid composition, but they differ in their oil content. The rapeseed oils do not contain erucic acid, but the seed oil of mustard contained 15.5 % eicosenoic acid.     

Studies on Herbaceous Seed Oils XI

Seeds from eight species were analysed by standard procedures for oil and protein contents. The fatty acid composition of the oils was determined by GLC. Five species were found to contain oils above 20% and none of them is rich in protein. Some of the oils have a composition fairly similar to the oils at present in common use. Five seed oils are interesting in having more than 50% of saturated acids of the total fatty acids. T. involucrata seed seems to be a promising species because of its high oil and linoleic acid (61.7%) contents.     

Gas-liquid chromatographic analysis of cyclopropene fatty acids

A gas-liquid chromatographic method is described for the quantitative estimation of cyclopropene fatty acids as their methyl mercaptan derivatives. This method estimates individual cyclopropene acids as well as normal and cyclopropane acids. Nine seed oils were analyzed for their cyclopropene fatty acid content. Evidence was obtained for the presence of a cyclopropene fatty acid of shorter chain length than malvalic inAlthaea rosea cav and one with a higher chain length than sterculic inBombacopsis glabra seed oil. This method is less accurate for cottonseed oil than for the other oils tested because of the appearance of some unsymmetrical peaks of unknown origin. The mercaptan derivatives of the cyclopropene acids may be isolated by silver ion thin-layer chromatography. Small amounts of cyclopropane fatty acids were found in a number of the oils analyzed for cyclopropene fatty acids. Presented at the AOCS meeting, Chicago, October 1964.     

Identification of the Unsaturated Heptadecyl Fatty Acids in the Seed Oils of <Emphasis Type="Italic">Thespesia populnea</Emphasis> and <Emphasis Type="Italic">Gossypium hirsutum</Emphasis>

The fatty acid composition of the seed oils of Thespesia populnea and cotton variety SG-747 (Gossypium hirsutum) were studied to identity their 17-carbon fatty acids. With a combination of chemical derivatization, gas chromatography, and mass spectrometry, 8-heptadecenoic acid, 9-heptadecenoic acid, and 8,11-heptadecadienoic acids were identified in both oils. Additionally, traces of 10-heptadecenoic acid were identified in the T. populnea oil. Although these odd-carbon number fatty acids are present in only minor amounts in cottonseed oil, they make up about ~2 % of the fatty acids in T. populnea seed oil. The identification of these acids indicates that fatty acid α-oxidation is not restricted to cyclopropene fatty acids in these plants, but also occurs with unsaturated fatty acids. Combined with malvalic acid (generally accepted as being formed by α-oxidation of sterculic acid), ~7 % of the fatty acids in T. populnea seed have under gone α-oxidization. The results should help clarify the composition of T. populnea seed oil, which has been reported inconsistently in the literature.     

Current advances in sunflower oil and its applications

The fatty acid and triacylglycerol composition of a vegetable oil determine its physical, chemical and nutritional properties. The applications of a specific oil depend mainly on its fatty acid composition and the way in which fatty acids are arranged in the glycerol backbone. Minor components, e. g. tocopherols, also modify oil properties such as thermo‐oxidative resistance. Sunflower seed commodity oils predominantly contain linoleic and oleic fatty acids with lower content of palmitic and stearic acids. High‐oleic sunflower oil, which can be considered as a commodity oil, has oleic acid up to around 90%. Additionally, new sunflower varieties with different fatty acids and tocopherols compositions have been selected. Due to these modifications sunflower oils possess new properties and are better adapted for direct home consumption, for the food industry, and for non‐food applications such as biolubricants and biodiesel production.     

Studies on Herbaceous Seed Oils V

Seeds from seven species of plants belonging to less familiar botanical families were analysed for oil and protein, and the fatty acid composition of the oils was determined by gas liquid chromatography. Oils from five species are interesting in containing high percentage (71.9–83.7%) of C₁₈ unsaturated acids. Seeds from Tropaeolum majus contain oil which, on the basis of chromatographic analysis, appears to be a suitable industrial source of cis-11-eicosenoic and cis-13-docosenoic (erucic) acids.     

γ-Linolenic and stearidonic acids in Mongolian Boraginaceae

Seeds of nine Central Asian species of Boraginaceae were investigated for the first time for their oil content and for the fatty acid composition of their seed oils by capillary gas chromatography. Levels of γ-linolenic acid ranged from 6.6 to 13.0% and levels of stearidonic acid ranged from 2.4 to 21.4% of total seed fatty acids. The seed oil ofHackelia deflexa exhibited the highest stearidonic acid content (21.4%) that has been found so far in nature. Other high contents of this fatty acid were in threeLappula species (17.2 to 18.1%). Seed oils ofCynoglossum divaricatum andAmblynotus rupestris contain considerable amounts ofcis-11-eicosenoic (5.3 to 5.8%) andcis-13-docosenoic acid (7.0 to 9.7%) besides γ-linolenic (10.2 to 13.0%) and stearidonic acid (2.4 to 6.5%), which distinguish these oils from those of other Boraginaceae genera. This paper was presented as a poster at 10th Minisymposium and Workshop on Plant Lipids, Sept. 3–6, 1995, in Berne, Switzerland.     

Composition of Catalpa ovata Seed Oil and Flavonoids in Seed Meal as Well as Their Antioxidant Activities

In view of the growing demand for vegetable oil, currently exploration of some non‐conventional oils is of great concern. This study firstly analyzed the contents of fatty acids, phytosterols, and tocopherols in Catalpa ovata seed oil collected from four different Provinces in China. Then the composition of flavonoids as well as their antioxidant activities in defatted seed meal was determined. The results showed that the relative oil content in C. ovata seeds ranged from 24.0 to 36.0 % and seed oil was mainly composed of fatty acids linoleic acid (43.4–50.1 %), α‐linolenic acid (23.8–24.4 %), and oleic acid (13.1–16.2 %). The content of unsaturated fatty acids was up to 85.0 %. Sterol in seed oil mainly contained campesterol, stigmasterol, and β‐sitosterol. β‐sitosterol accounted for 74.0 % of the total sterol. The tocopherol content was 173.0–225.7 mg/100 g. Defatted seed meal from Hubei Province showed the highest content of total flavonoids (11 mg/g) and the strongest activities for DPPH radicals scavenging, ABTS radicals scavenging, and ferric reducing antioxidant power compared with other defatted seed meal in this study. Seven flavonoids were identified from C. ovata seed meal. These results suggest that C. ovata seeds may be developed as a new source of oil and can also be properly used in pharmaceuticals and cosmetics.     

Chemical evaluation of egyptian citrus seeds as potential sources of vegetable oils

Seeds of the citrus fruits orange, mandarin, lime and grapefruit were analyzed. Petroleum ether-extracted oils of such seeds amounted to more than 40% of each. Physical and chemical properties of the extracted oils are presented. Samples of the extracted oils were saponified and the unsaponifiables and fatty acid fractions isolated. The isolated unsaponifiables and fatty acids were analyzed by GLC. GLC analysis of the unsaponifiables revealed compositional patterns differ-ent in number, type and relative concentration of fractions according to type of citrus seed oil, depending on the solvent system used for oil extraction and unsaponifiable matter isolation. The compositional patterns of the unsaponifiables were similar to that of cottonseed oil. Mandarin and grapefruit oils are free of cholesterol. The data demonstrate that the fatty acid compositional patterns of the oils differ; Mandarin seed oil contains the largest number of fatty acids, and grapefruit seed oil contains the lowest. The total amounts of volatile fatty acids in these oils are generally higher than those of other edible oils. Lime seed oil is similar, in the degree of unsaturation, to soybean oil. The orange oil pattern is similar to cottonseed oil. The amount of total essential fatty acids in lime seed oil is the highest of the oils studied.     

Investigation of the technological properties ofNigella sativa (black cumin) seed oil

Three commercially cultivatedNigella sativa seed varieties of Turkish origin were analyzed, and the characteristics and constituents of the seed oils were reported. Presence of lipase enzyme in seed results in enzymatic hydrolysis at ordinary temperature; the free acid content of oil may increase up to 40% or higher. Black cumin seed oil might serve as a source of semi-drying oil and fatty acids of technical grade, and the removal of free fatty acids from oil and the recovery of fatty acids were investigated.     

Tomato Seed Oil I Fatty Acid Composition,Stability and Hydrogenation of the Oil

Tomato seed oil was investigated to study their components of fatty acids, stability and hydrogenation conditions. The estimation of the fatty acids of tomato seed oil from Ace variety and tomato seed oil extracted from local waste in comparison with cotton seed oil (the most familiar edible oil in Egypt) - Giza 69 variety - extracted by n-hexane and oil obtained by pressing shows that more than 50% of the total fatty acids are linoleic. Palmitic acid was found in a range between 20% to 29% and oleic acid was in a range between 13% to 18%. Other fatty acids like stearic, arachidic, and linolenic acid were less than 3%. The induction periods (at 100°C) for oils of fresh, roasted and stored tomato seeds were found to be 7, 10, and 5 hours respectively. The hydrogenation conditions of crude tomato seed oil were 180°C, 3 kg/cm² and 0.2% nickel catalyst for three hours of hydrogenation to reach a melting point of 50.7°C and an iodine value of 42.     

Detection of adulteration

A program of work is in progress to establish the levels and ranges of fatty acids and other components present in the major edible vegetable oils. Authentic samples from the major producing areas for such oil have been obtained and analyzed. In the case of palm oil, ranges of the fatty acid composition and of the acids at the triglyceride 2-position, have been obtained for about 40 samples. These data were used to calculate enrichment factors, and triglyceride carbon number compositions, using a small computer program. Comparison with experimentally determined carbon number compositions were then made. Good correlations were found for whole unadulterated oils, but not for oil fractions. Unfortunately, these differences were insufficient to detect contamination of palm oil by 10 or 20% levels of other oils, or of palm fractions. Compositional ranges of sterols and tocopherols have also been determined on a selection from the original set of palm samples. Work on sunflower seed and groundnut oils has followed the same lines, particular attention having been paid to linolenic acid and, in the case of groundnut oil, also erucic acid, levels. Some groundnut kernels were found to have an oil with a component which cochromatographed with methyl erucate during fatty acid determination. This unknown constituent was studied by gas chromatography-mass spectrometry, and is thought to comprise a mixture of epoxy fatty acids. Analysis of the triglyceride fraction isolated from groundnut oil by thin layer chromatography removes this unknown constituent, and simplifies interpretation of the fatty acid composition of groundnut oil.     

Oxidative Stability and Changes in Chemical Composition of Extra Virgin Olive Oils After Short‐Term Deep‐Frying of French Fries

We aimed at investigating oxidative stability and changes in fatty acid and tocopherol composition of extra virgin olive oil (EVOO) in comparison with refined seed oils during short‐term deep‐frying of French fries, and changes in the composition of the French fries deep‐fried in EVOO. EVOO samples from Spain, Brazil, and Portugal, and refined seed oils of soybean and sunflower were studied. Oil samples were used for deep‐frying of French fries at 180 °C, for up to 75 min of successive frying. Tocopherol and fatty acid composition were determined in fresh and spent vegetable oils. Tocopherol, fatty acid, and volatile composition (by SPME–GC–MS) were also determined in French fries deep‐fried in EVOO. Oil oxidation was monitored by peroxide, acid, and p‐anisidine values, and by Rancimat after deep‐frying. Differential scanning calorimetry (DSC) analysis was used as a proxy of the quality of the spent oils. EVOOs presented the lowest degree of oleic and linoleic acids losses, low formation of free fatty acids and carbonyl compounds, and were highly stable after deep‐frying. In addition, oleic acid, tocopherols, and flavor compounds were transferred from EVOO into the French fries. In conclusion, EVOOs were more stable than refined seed oils during short‐term deep‐frying of French fries and also contributed to enhance the nutritional value, and possibly improve the flavor, of the fries prepared in EVOO.     

Some chemical processes utilizing oleic safflower oil

Oleic safflower seed (UC-1) produces an oil containing approximately 80% oleic acid and 12% linoleic acid. The oil is a source of high quality oleic acid, and fatty acids from the oil may be used without further separation in some applications where technical oleic acid is now used, since oleic safflower free fatty acids have a a higher oleic acid content than good commercial grades of oleic acid. A high purity oleic acid can be produced by urea fractionation. Ozonization of the oil followed by reductive cleavage yields pelargonaldehyde and nearly colorless aldehyde oils. Ozonization of a crude mixture of oleic safflower acids followed by oxidative cleavage provides high yields of azelaic acid and pelargonic acid. In contrast, ozonization of free fatty acids from polyunsaturated vegetable oils produces azelaic acid and mixtures of lower molecular weight carboxylic acids with smaller amounts of pelargonic acid. Furtherore, ozone consumption is lower and reaction time is shorter when oleic safflower acids are used in place of more highly unsaturated fatty acids.     

Fatty Acid Profile of Kenaf Seed Oil

The fatty acid profile of kenaf (Hibiscus cannabinus L.) seed oil has been the subject of several previous reports in the literature. These reports vary considerably regarding the presence and amounts of specific fatty acids, notably (12,13-epoxy-9(Z)-octadecenoic (epoxyoleic) acid, but also cyclic (cyclopropene and cyclopropane) fatty acids. To clarify this matter, two kenaf seed oils (from the Cubano and Dowling varieties of kenaf) were investigated regarding their fatty acid profiles. Both contain epoxyoleic acid, the Cubano sample around 2 % and the Dowling sample 5-6 % depending on processing. The cyclic fatty acids malvalic and dihydrosterculic were identified in amounts around 1 %. Trace amounts of sterculic acid were observed as were minor amounts of C17:1 fatty acids. The results are discussed in the context of the fatty acid profiles of other hibiscus seed oils.     

Component fatty acids of some cruciferae oils

Summary The oils from yellow mustard seed (Brassica alba), black mustard seed (Brassica nigra) of Indian origin, and rapeseed (Brassica Compestris) of unknown origin have been analyzed for their fatty acid composition without preliminary resolution of fatty acids by lead-salt-alcohol or fractional crystallization methods. The results compare very favorably with those determined by other recently developed methods. It may be concluded therefore that this method can be favorably employed for the determination of fatty acid composition of fats containing higher unsaturated acids. Confirmatory evidence has been obtained for the presence of eicosenoic acid in rapeseed oil. The nature and amount of fatty acids of yellow mustard seed oil of Indian origin do not differ in any significant manner from those of other cruciferous seed oils. The present analysis of black mustard seed oil reveals a higher amount of linolenic acid, and the presence of a C₂₀ monoethenoid acid, not heretofore reported. Contribution No. 708 from the Department of Chemistry, University of Pittsburgh. Presented in part at the Spring meeting of the American Oil Chemists’ Society, held in New Orleans, La., May, 1948. Baliga and Hilditch’s paper. “The Component Acids of Rapeseed Oil” (J. Soc. Chem. Ind.67, 258–262 (1948).