Nachweis und Bestimmung von cyclischen C18-Fettsäuren in isomerisiertem Leinöl

Detection and Determination of Cyclic C₁₈-Fatty Acids in Isomerised Linseed Oil When linseed oil is isomerised with ethylene glycol and KOH under conditions which are employed for the UV-spectrophotometric determination of linoleic and linolenic acids, isomeric C₁₈-cyclic fatty acids to an extent of 10% of the linseed oil (20% of linolenic acid) are formed besides straight chain conjugated fatty acids. Lesser amount of cyclic acids are formed if the isomerisation is carried out with NaOH-ethylene glycol or K-tert-butylate. Ilinol, a linseed oil obtained by catalytic isomerisation with Ni/S, was found to contain ca. 5% cyclic C₁₈ fatty acids. The cyclic fatty acids are mixtures of many isomers, their composition being dependent on the conditions employed for isomerisation.     

Chemical Composition and Fatty Acid Profile of Khat (Catha edulis) Seed Oil

The proximate, physicochemical, and fatty acid compositions of seed oil extracted from khat (Catha edulis) were determined. The oil, moisture, crude protein, crude fiber, crude carbohydrate, and ash content in seeds were 35.54, 6.63, 24, 1.01, 30.4 %, and 1.32 g/100 g DW respectively. The free fatty acids, peroxide value, saponification value, and iodine value were 2.98 %, 12.65 meq O₂/kg, 190.60 mg KOH/g, and 145 g/100 g oil, respectively. Linolenic acid (C_18:3, 50.80 %) and oleic (C_18:1, 16.96 %) along with palmitic acid (C_16:0, 14.60 %) were the dominant fatty acids. The seed oil of khat can be used in industry for the preparation of liquid soaps and shampoos. Furthermore, high levels of unsaturated fatty acids make it an important source of nutrition especially as an animal product substitute for omega‐3 fatty acids owing to the high content of linolenic acid.     

Extraction of pomegranate seed oil using subcritical propane and supercritical carbon dioxide

Extraction of oil from pomegranate seeds as a waste product of the juice industry using supercritical carbon dioxide and subcritical propane was studied in this work. The influence of the main operating conditions of extraction, namely, the temperature and pressure of extraction on the oil extraction yield and the correspondent fatty acid profile were analyzed and reported here. Soxhlet extraction with n-hexane was done for comparison with supercritical extraction resulting in a maximum yield of oil of 22.31 wt %. Supercritical carbon dioxide and subcritical propane extracted up to 58.53% (corresponding to maximum yield of 13.06 wt %) and 76.73% (corresponding to maximum yield of 17.12 wt %) of the total amount of pomegranate seed oil as measured using Soxhlet extraction, respectively. Results indicated that the subcritical propane is a suitable and selective solvent for the extraction of the pomegranate seed oil in function of smaller times and pressures employed compared to carbon dioxide extraction. The fatty acid composition of the extracted oil showed the presence of fatty acids of C₁₆, C₁₈, C₂₀, C₂₂, and C₂₄ carbon chains. Punicic (C_18.3) was the major fatty acids and comprise up to 70% of the total fatty acid content of the extracted oil among all samples. Finally, Lack??s plug flow model as developed by Sovova was applied to both extraction systems and a good agreement with the experimental results was obtained.     

Characterization of the seed oils of some commercial cultivars of melon

Proximate analysis of the seeds from three commercial melon cultivars (Honey Dew, Hy‐mark and Orange Flesh) showed high percentage of lipids (25.7—27.6%) and proteins (15.2—19.2%). The physico‐chemical properties of the hexane‐extracted oil from the seeds of these cultivars were determined. Gas chromatographic analysis of the oils showed the presence of almost all fatty acids starting from C₆— C₂₄ except that of C₁₁ , C₂₁ C₂₃ , C_18:2 being the principal fatty acid followed by C_18:1 , C_16:0 , and C_18:0 fatty acids. The number of fatty acids, which were present in concentrations higher than 0.01% of total fatty acids, was 17, 14, and 13, respectively, in these cultivars     

Hydrogenation of a menhaden oil: I. Fatty acid and C20 monoethylenic isomer compositions as a function of the degree of hydrogenation

US menhaden oil is rich in long-chain polyethylenic fatty acids, chiefly C₂₀ (eicosapentaenoic) and C₂₂ (docosahexaenoic) fatty acids, unlike Canadian herring oil, which is rich in long-chain (C₂₀ and C₂₂) monoethylenic fatty acids. An examination of the product fatty acids from hydrogenation of menhaden oil therefore comple-ments studies previously published for herring oil. During a commer-cial hydrogenation of menhaden oil, iodine value (IV) 159.0, on nickel catalyst, samples were collected at IV 150.0, 140.0, 131.5, 120.5, 96.5, 90.0 and 84.5. The fatty acid compositions were deter-mined using a combination of mercuric adduct fractionation and gas liquid chromatographic (GLC) analyses, and the totaltrans content by infrared spectroscopy. The partial hydrogenation resulted in the disappearance of the pentaenoic and hexaenoic fatty acids, a de-crease in tetraenes, and a definite increase in trienes, 8.3% at IV 84.5 compared to 4.2% at IV 159.0. The dienoic fatty acids in-creased to 13.2% at IV 84.5 compared to 4.1% at IV 159.0, and the monoenoic fatty acids increased to 34.2% from 24.0%. No impor-tant changes in the saturated acids were observed, 43.8% at IV 84.5 compared to 41.6% at IV 159.0. The totaltrans content varied from 3.4% at IV 150.0 to 45.1% at an IV of 84.5. The isomer composi-tions of thecis andtrans C₂₀ monoethylenic fatty acids were deter-mined using a combination of preparative GLC, AgNO₃ thin layer chromatography and ozonolysis. Thecis 20:1 acids at IV 84.5 still retained 27.5% of the major isomer (All) originally present at 72%. The parent A5, A8, All, A14 and A17 bonds of the 20:5 originally present could be detected in thecis 20:1 isomers at IV 96.5 but not at IV 84.5. At IV 84.5, 58% of the 20:1was trans, the major isomer being All (9.4% of total 20.1), accompanied by important quanti-ties of Δ10 and Δ12, respectively, 6.9% and 6.6% of the total 20:1. Presented in part at the 73rd annual AOCS meeting, Toronto, 1982.     

Characterization of chilean hazelnut (Gevuina avellana mol) seed oil

The fatty acid composition, tocopherol and tocotrienol content, and oxidative stability of petroleum benzene-extracted Gevuina avellana Mol (Proteaceae) seed oil were determined. Positional isomers of monounsaturated fatty acids were elucidated by gas chromatography-electron impact mass spectrometry after 2-alkenyl-4,4-dimethyloxazoline derivatization. This stable oil (Rancimat induction period at 110°C: 20 h) is composed of more than 85% monounsaturated fatty acids and about equal amounts (6%) of saturated and polyunsaturated (principally linoleic) fatty acids. Unusual positional isomers of monounsaturated fatty acids, i.e., C_16:1 Δ¹¹, C_18:1 Δ¹², C_20:1 Δ¹¹, C_20:1 Δ¹⁵, C_22:1 Δ¹⁷, and presumably C_22:1 Δ¹⁹ were identified. The C_18:1 Δ¹² and C_22:1 Δ¹⁹ fatty acids are described for the first time in G. avellana seed oil. While only minute quantities of α-, γ-tocopherols and β-, γ- and δ-tocotrienols were found, the oil contained a substantial amount of α-tocotrienol (130 mg/kg). The potential nutritional value of G. avellana seed oil is discussed on the basis of its composition.     

Competitive adsorption among sesame oil components in a concentrated miscella system

Competitive adsorption of free fatty acids and carotenoids adsorption from sesame oil miscellas on vegetable carbon was studied by regression analysis. The equations obtained indicated that unsaturated carbonyls, free fatty acids (FFA₀), and carotenoids interacted to determine fatty acid and carotenoid adsorption. The driving force for carotenoid adsorption, the carotenoid concentration (C₀), was affected by a quadratic function of free fatty acid concentration [i.e., (FFA₀/C₀)²]. As FFA₀/C₀ increased, carotenoid adsorption efficiency was reduced, possibly because the accessible adsorption sites for carotenoids were occupied by fatty acids. Unsaturated carbonyls promoted free fatty acid adsorption, probably in the pores that were readily accessible for fatty acids. However, when the carbonyl concentration increased in the oil miscella, carbonyls were adsorbed instead of fatty acids. The results indicated how different oil molecules interact and affect adsorption (i.e., free fatty acids and carotenoids). Therefore, the adsorption process of vegetable oils (i.e., bleaching) has to be considered a multicomponent adsorption system.     

Synthesis and Surface Active Properties of Sulfonated Acrylate Esters Based on Al‐Cedre Oil

Sulfonated acrylate esters have been synthesized by using renewable raw materials such as fatty alcohols of Al‐Ceder oil. Mixed fatty acids were isolated from Al‐Ceder oil by hydrolysis; both saturated and unsaturated fatty acids were isolated from the mixed fatty acids. The methyl esters of mixed fatty acid, saturated and unsaturated acids of Al‐Cedre oil were subjected to reduction with (LiAlH4) to give the corresponding fatty alcohols. The products of the reduction process were saponified and the hydroxyl values were estimated to further confirm the reduction occurrence. The acrylate esters were synthesized by esterification of acrylic acid with fatty alcohols of C_16:0, C_18:0, C_18:1, and C_18:2 mixed saturated, mixed unsaturated and mixed fatty acids of Al‐Cedre oil, respectively. This esterification was followed by addition of NaHSO₃ to form bisulfite adducts. The structures of the prepared surfactants were characterized by IR and ¹HNMR spectroscopy. A series of useful surface parameters, stability towards acids and base hydrolysis and calcium stability have been determined.     

Über das Fenchelölwachs

Studies on the Wax of Fennel Seed Oil Wax isolated from fennel seed oil was analyzed. It contains 2.8% unsaturated fatty acids (C₁₅–C₁₈) and 97.2% saturated fatty acids (C₁₃–C₂₂). In this investigation chemical, ion-exchange, adsorption and gas-liquid chromatographic methods were employed.     

Component fatty acids of marine fish liver oils

Summary 1. Two liver oils (Elasmobranch) fromCarcharias melanopterus andPristis cuspidatus, caught off the Madras coast are studied, and their component fatty acids are reported. 2. The mixed acids were separated into three groups (varying unsaturation) of acids, and their methylesters were fractionated. 3. The liver oils are found to belong to the fourth group of Tsujimoto’s classification of Elasmobranch fish liver oils.Carcharias melanopterus liver oil contains 31.1% unsaturated acids (myristic 3.1, palmitic 18.4, stearic 9.5, and 0.1% arachidic) and 68.9% unsaturated acids (C₁₆ 10.8, C₁₈ 19.7, C₂₀ 15.2, C₂₂ 17.1, C₂₄ 5.3%, and traces of C₁₄ monoethenoid).Pristis cuspidatus liver oil contains 36.9% saturated acids (myristic 1.2, palmitic 22.9, stearic 12.7, and arachidic 0.1%) and 67.1% unsaturated acids (C₁₆ 8.2, C₁₈ 28.5, C₂₀ 16.4, C₂₂ 5.2, C₂₄ 4.6%, and traces of C₁₄ monoethenoid). The unsaturations of the different groups of acids are almost of the same order. 4. The abnormal content of saturated acids can be explained by the process of bio-hydrogenation. The relatively less amount of saturated acids inCarcharias melanopterus liver oil along with its higher content of polyethylenic acids (C₂₀ and above) points strongly to the possible presence of intermediate types of fats among the four groups of Elasmobranch oils.     

Medium-chain fatty acid-rich glycerides by chemical and lipase-catalyzed polyester-monoester interchange reaction

Medium-chain triglycerides (MCT) that contain caprylic acid (C_8:0) and capric acid (C_10:0) have immense medicinal and nutritional importance. Coconut oil can be used as a starting raw material for the production of MCT. The process, based on the interchange reaction between triglycerides and methyl esters of medium-chain fatty acids by chemical catalyst (sodium methoxide) or lipase (Mucor miehei) catalyst, appears to be technically feasible. Coconut oils with 25–28.3% (w/w) and 22.1–25% (w/w) medium-chain fatty acids have been obtained by chemical and lipase-catalyzed interchange reactions. Coconut olein has also been modified with C_8:0 and C_10:0 fatty acids, individually as well as with their mixtures, by chemical and lipase-catalyzed interchange reactions. Coconut olein is a better raw material than coconut oil for production of mediumchain fatty acid-rich triglyceride products by both chemical and lipase-catalyzed processes.     

Studies on Mirabilis jalapa (Four O'clock Plant) Seed Oil

Mirabilis jalapa of Nyctaginaceae plant family yields 4–5% of fatty oil. The oil is investigated for its glycerides and fatty acid composition by gas liquid chromatography. The fatty acids in the seed oil constitute C_16:0, 18.3%;C_18:1,55.3%;C_18:2,11.5%;C_18:3,14.9%. The triglyceride components were also determined by separating the triglycerides according to their degree of unsaturation by means of thin-layer chromatography on silica gel impregnated with silver nitrate. The fatty acid composition of the different triglyceride fractions was determined. Moreover, the triglycerides were separated according to their carbon number by gas liquid chromatography.     

Monoethylenic fatty acids of a partially hydrogenated herring oil

A Canadian Atlantic herring oil hydrogenated for margarine use to an iodine value of 76 and melting point of 32.5 C was found to have 30% saturated acids and 66% monounsaturated fatty acids. The monounsaturated fatty acids could be analytically determined ascis andtrans isomers by open tubular gas liquid chromatography.Trans acids were 33% of the C₁₆ and C₁₈ monounsaturated acids, and 32 and 28%, respectively, of the C₂₀ and C₂₂ monounsaturated acids. After separation of geometric isomers by Florisil-silver nitrate chromatography the positional isomers in each class were determined by oxidative fission. The double bond positions of the originalcis fatty acids were largely retained in bothcis andtrans isomers, but additional isomers were observed, especially in thetrans fatty acids.     

Enzymatic synthesis of medium‐chain triacylglycerols by alcoholysis and interesterification of copra oil using a crude papain lipase preparation

We have examined the possibility of producing analogs of medium‐chain triglycerides (MCT) from copra oil, i.e. a triacylglycerol mixture with a high content of medium‐chain fatty acid moieties (C₆–C₁₀). A two‐step enzymatic process was used in which copra triacylglycerols were first split with papain lipase by alcoholysis with an alkyl alcohol and then subjected to interesterification with the alkyl esters recovered using papain lipase. Effects of temperature, water activity content, substrate ratio, biocatalyst amount, and alcohol chain length were also investigated. On the one hand, the sn‐3 stereoselectivity of the lipase in the alcoholysis of copra oil with butanol has permitted a direct enrichment of caproic, caprylic and capric moieties in the synthesized butyl esters. Thus, in the batch reactor, the reaction led to about 31% conversion of the oil after 24 h, and the content of C₆–C₁₀ acids in the synthesized esters increased from about 16% in the starting oil to almost 42%. A similar enzymatic alcoholysis in a packed‐bed column bioreactor gave 31% conversion of the oil after 120 min of reactor residence time. The reaction was also very selective because the C₆–C₁₀ fatty acyl groups represented about half of the newly formed butyl esters, whereas they accounted for only 16% of total fatty acids in the starting oil. On the other hand, the transesterification of the alkyl esters recovered (highly enriched in C₆–C₁₀ fatty acyl groups) with native copra oil directly led to an increase in the content of MCT in the oil, from 18 mol‐% at the beginning of the reaction to 61 mol‐% of MCT after a time period of 72 h in the batch reactor.     

Variability in fatty acid composition amongArachis genotypes: A potential source of product improvement

Research on peanut (Arachis hypogeae L.) genotypes has shown a high degree of genetic variability in fatty acid composition. The two major oil fatty acids, oleic and linoleic, range between 36–69% and 14–40%, respectively, and together make up 75–85% of total fatty acids. The very long chain (C₂₀–C₂₄) fatty acids make up 4–9%, palmitic acid 7–13%, and stearic acid 2–5% of total fatty acids. Stability of oil samples as measured by length of autoxidation induction period at 60 C shows variable but statistically significant (P<0.01) correlations with levels of linoleic acid; peanut butter samples show similar patterns of stability. Selection for lower levels of linoleic acid in the development of new varieties of peanuts should results in products with significantly improved shelf life. Some genotypes show consistent differences in oil stability patterns that are not related to oil linoleic acid content. Analysis of entries from 16 wildArachis species collections revealed levels of oil linoleic acid higher than those found inA. hypogaea. One species,A. villosulicarpa, contained 49% linoleic acid and 21% very long chain acids. The range in linoleic acid withinA. hypogaea and availability of suitable techniques for measuring selection progress give scope for product improvement through breeding.     

Full Characterisation of Crambe abyssinica Hochst. Seed Oil

This work was dedicated to reporting the full chemical and physical characterisation of Crambe abyssinica Hochst. seed oil. The oil from the seeds was extracted using n-hexane. The seeds contain about 30?% oil. Density, refractive index, colour, smoke point, viscosity, acidity, saponification value, iodine value, fatty acid methyl esters, the relative position of fatty acids in C₁ and C₃ carbon glycerol, sterols, tocopherols, peroxide value, $ \mathop E\nolimits_{{1{\text{cm}}}}^{1\,\% } $ at 232?nm, and the susceptibility to oxidation measured by the Rancimat method were determined. The oil was found to contain high levels of unsaturated fatty acids, especially C22:1 (63.77?%). The dominant saturated acid was C22:0 (2.14?%). The oil was also found to contain high levels of β-sitosterol (51.93?%), campestanol (21.98?%), and brassicasterol (12.35?%). α-, γ-, and δ-Tocopherols were detected up to levels of 7.67, 125.04, and 3.99?mg/kg, respectively. The induction period (at 110?°C and 20?l/h) of the oil was 8.83?h. The relative position of fatty acids in C₁ and C₃ position was as follows: linoleic 0.45?%, oleic 8.84?%, and erucic 90.72?%. The thermal profile of the oil presented a single peak at ?20.94?°C.     

Unsaturated C18 α-hydroxy acids inSalvia nilotica

The oil ofSalvia nilotica Jacq. (Labiatae) seed contains 0.6% α-hydroxyoleic, 4.2% α-hydroxylinoleic, and 5.4% α-hydroxylinolenic acids. The first two have not been found previously in seed oils. In addition to the common fatty acids, also identified were small amounts of three unsaturated C₁₇ acids and one branched chain C₁₇ acid. Methyl esters of the component fatty acids were fractionated by both column and thin-layer chromatography. These esters were identified by combination of gas chromatography, GC-mass spectrometry, ozonolysis-GC, infrared, and nuclear magnetic resonance.     

Marine-derived fatty acids of fish oils as raw materials for fatty acids manufacture

Fish oils, often an abundant source of C₂₀ and C₂₂ fatty acids, could supplement rapessed oil in the manufacture of long chain saturated fatty acids. Herring oil, traditionally the fish oil of choice, is in very short supply due to depletion of fishery stocks. Menhaden oil, when made from fish caught in the Atlantic, could furnish a steady supply with long chain acids at about the 30% level. Oil made from other species such as anchovy or pilchard need further data on fatty acid content and variability. Manufacture of polyunsaturated fatty acids from fish oils is hampered by lack of suitable procedures. Potential markets for fish oil polyunsaturates especially in the pharmaceutical field seem promising.     

Chemical Composition and Nutritional Characteristics of the Seed Oil of Wild <Emphasis Type="Italic">Lathyrus</Emphasis>, <Emphasis Type="Italic">Lens</Emphasis> and <Emphasis Type="Italic">Pisum</Emphasis> Species from Southern Spain

The fatty acid composition of the seed oil of 19 wild legume species from southern Spain was analyzed by gas chromatography. The main seed oil fatty acids ranged from C_14:0 to C_20:0. Among unsaturated fatty acids, the most abundant were linoleic, oleic and linolenic acids, except for Lathyrus angulatus, L. aphaca, L. clymenum, L. sphaericus and L. nigricans where C_18:3 contents were higher than C_18:1 contents. Palmitic acid was the most abundant saturated acid in studied species, ranging from 11.6% in Lathyrus sativus to 19.3% in Lens nigricans. All studied species showed higher amounts of total unsaturated fatty acids than saturated ones. Among studied species, the ω6/ω3 ratio was variable, ranging from 2.0% in L. nigricans to 13.8% in L. sativus, there being eight species in which the ω6/ω3 ratio was below 5. The fatty acids observed in these plants supports the use of these plants as a source of important dietary lipids.     

Palmitoleic acid inRoureopsis obliquifoliata (Connaraceae) Seed oil

Roureopsis obliquifoliata Schellenberg seeds contain an oil (45% by weight) comprised primarily of 16-carbon fatty acids. Palmitic acid constitutes 50% of the fatty acids, palmitoleic acid 32%, and small amounts of the usual C₁₈ acids make up the remainder. Identifications were based on Chromatographic properties of the acids and their ozonolysis products.