Variations in the composition of sterols,tocopherols and lignans in seed oils from fourSesamum species

Seeds from different collections of cultivatedSesamum indicum Linn and three related wild species [specifically,S. alatum Thonn.,S. radiatum Schum & Thonn. andS. angustifolium (Oliv.) Engl.] were studied for their oil contents and fatty acid composition of the total lipids. The oils from wild seeds were characterized by higher percentages of unsaponifiables (4.9, 2.6 and 3.7%, respectively) compared toS. indicum (1.4–1.8%), mainly due to their high contents of lignans. Total sterols accounted forca. 40, 22, 20 and 16% of the unsaponifiables of the four species, respectively. The four species were different in the relative percentages of the three sterol fractions (the desmethyl, monomethyl and dimethyl sterols) and in the percentage composition of each fraction. Campesterol, stigmasterol, sitosterol and Δ⁵-avenasterol were the major desmethyl sterols, whereas obtusifoliol, gramisterol, cycloeucalenol and citrostandienol were the major monomethyl sterols, and α-amyrin, β-amyrin, cycloartenol and 24-methylene cycloartanol were the main dimethyl sterols in all species. Differences were also observed among the four species in sterol patterns of the free sterols compared to the sterol esters.Sesamum alatum contained less tocopherols (210–320 mg/kg oil), andS. radiatum andS. angustifolium contained more tocopherols (ca. 750 and 800 mg/kg oil, respectively) than didS. indicum (490–680 mg/kg oil). The four species were comparable in tocopherol composition, with γ-tocopherol representing 96–99% of the total tocopherols. The four species varied widely in the identity and levels of the different lignans. The percentages of these lignans in the oils ofS. indicum were sesamin (0.55%) and sesamolin (0.50%).Sesamum alatum showed 1.37% of 2-episesalatin and minor amounts of sesamin and sesamolin (0.01% each).Sesamum radiatum was rich in sesamin (2.40%) and contained minor amounts of sesamolin (0.02%), whereS. angustifolium was rich in sesangolin (3.15%) and also contained considerable amounts of sesamin (0.32%) and sesamolin (0.16%).     

Seed Lipids of Sesamum indicum,L. and Related Wild Species in Sudan I: Fatty Acids and Triacylglycerols

The fatty acid composition and triacylglycerol profile of seeds of three wild species of sesame viz, Sesamum alatum, Thonn., S. radiatum, Schum & Thonn. and S. angustifolium, (Oliv) Engl. were determined by capillary gas chromatography and high performance liquid chromatography, respectively. Results were compared with those obtained for different pure line and mixed genotypes of S. indicum, Linn., the overall world wide cultivated sesame. Oleic and linoleic acids are the major fatty acids in all samples. The wild species have slightly different saturated acid composition compared to S. indicum. S. alatum contained more palmitic acid (P) while S. radiatum and S. angustifolium contained more stearic acid. S. alatum also contained higher amounts of oleic acid (O) and lower amounts of linoleic acid (L). The major triacylglycerols were: LLO (20–25%), LLL (10–20%), LOO (15–19%), PLL (8–11%) and PLO (6–10%). S. alatum was also different from the other three species in having higher percentages of PLO (10.1%) and OOO (8.7%) compared to 6.3–8.1% of PLO and 3.4–4.9% of OOO in the other three species.     

Varietal difference in lipid content and fatty acid composition of highbush blueberries

Lipids from five cultivars of highbush blueberries (Vaccinium corymbosum L.) were extracted and fractionated into neutral lipids (60–66%), glycolipids (20–22%) and phospholipids (14–18%). The major fatty acids in all fractions were palmitic (16∶0), oleic (18∶1), linoleic (18∶2), and linolenic (18∶3) acids. All lipid classes had a large concentration of C₁₈ polyunsaturated acids (84–92%), indicating that blueberries are a rich source of linoleic and linolenic acids. Changes in the fatty acid composition of neutral lipids and phospholipids were not significantly different among the five cultivars, but significant differences were noted in the ratios of linoleic and linolenic acids in the glycolipids fraction.     

Lipid Classes,Fatty Acid Distributions and Triacylglycerol Molecular Species of Broad Beans (<Emphasis Type="Italic">Vicia faba</Emphasis>)

Seed oils from four legume cultivars of Vicia faba, grown in Japan, were extracted and classified by thin-layer chromatography (TLC) into eight fractions. The major lipid components were triacylglycerols (TAG: 48.8–50.1%) and phospholipids (PL: 47.5–50.5%), while hydrocarbons (HC), steryl esters (SE), free fatty acids (FFA), diacylglycerols (1,3- and 1,2-DAG) and monoacylglycerols (MAG) were present in minor proportions (1.8–2.4%). All lipid samples had high amounts of total unsaturated FA, representing 79.7–82.8% and 77.6–79.7% for TAG and PL, respectively. Molecular species and FA distributions of TAG, isolated from the total lipids in the broad beans, were analyzed by a combination of argentation-TLC and GC. Fourteen different molecular species were detected. With a few exceptions, the main TAG components were S₂D (6.1–8.9%), SD₂ (7.8–10.5%), SMT (6.3–8.5%), M₂D (4.5–6.2%), MD₂ (18.9–21.8%), D₃ (21.0–23.9%) and MDT (8.1–10.2%) (where S, M, D, and T denote a saturated fatty acid, a monoene, a diene, and a triene, respectively). These results suggest that the lipid classes, FA distributions and TAG molecular species of broad beans are not dependent on the cultivation areas during the growing season.     

Determination ofcis andtrans-Octadecenoic acids in margarines by gas liquid chromatography-infrared spectrophotometry

A combined capillary gas liquid chromatography (GLC) and infrared spectrophotometry (IR) method is described for the determination ofcis andtrans-octadecenoic acids in margarines made from partially hydrogenated vegetable oils. The totaltrans-unsaturation of margarine fatty acid methyl esters determined by IR, with methyl elaidate as the external standard, was correlated to the capillary GLC weight percentages of the componenttrans fatty acid methyl esters by the mathematical formula: IRtrans=%18∶1t+0.84×%18.2t+1.74×%18∶2tt+ 0.84×%18∶3t where 0.84, 1.74 and 0.84 are the correction factors which relate the GLC weight percentages to the IRtrans-equivalents for mono-trans-octadecadienoic (18∶2t),trans, trans-octadecadienoic (18∶2tt) and mono-trans-octadecatrienoic (18∶3t) acids, respectively. This formula forms the basis for the determination of totaltrans-andcis-octadecenoic acids in partially hydrogenated vegetable oils. From the weight percentages of 18∶2t, 18∶2tt and 18∶3t determined by capillary GLC on a cyanosilicone liquid phase and the totaltrans-unsaturation by IR, the percentage of the totaltrans-octadecenoic acids (18∶1t) is calculated using the formula. The difference between the total octadecenoic acids (18∶1), determined by capillary GLC, and the 18∶1t gives the totalcis-octadecenoic acids. Presented in part at the 81st Annual Meeting of the American Oil Chemists' Society, Baltimore, Maryland, April 22–25, 1990.     

Variation in lipid composition of niger seed (Guizotia abyssinica Cass.) Samples collected from different regions in ethiopia

Niger seed samples were collected from different regions in Ethiopia for determination of oil content, and of fatty acid, tocopherol and sterol composition in the seed oil by gas-liquid chromatography and high-performance liquid chromatography methods. There was a large variation in oil content, ranging from 29 to 39%. More than 70% of the fatty acids was linoleic acid (18∶2) in all samples analyzed. The other predominant fatty acids were palmitic (16∶0), stearic (18∶0) and oleic (19∶1) at a range of 6 to 11% each. Total polar lipids recovered after preparative thin-layer chromatography comprised a small fraction of the total lipids. They had higher 16∶0 and lower 18∶2 contents than the triacylglycerols.α-Tocopherol was the predominant tocopherol in all samples, 94–96% of the total amounting to 630–800 μg/g oil. More than 40% of the total sterols wasβ-sitosterol,ca. 2000μg/g oil. The other major sterols were campesterol and stigmasterol, ranging from 11 to 14%. The Δ5- and Δ7-avenasterols were in the range of 4 to 7%. From the samples studied, no conclusion could be drawn regarding the influence of altitude or location on oil content, tocopherol and/or sterol contents. The results of the present study on niger seed oil are discussed in comparison with known data for common oils from Compositae,viz, safflower and sunflower.     

Fatty acid and triacylglycerol compositions of seed oils of five Amaranthus accessions and their comparison to other oils

This paper reports the fatty acid and triacylglycerol (TAG) compositions of five Amaranthus accessions (RRC1011, R149, A.K343, A.K432, and A. K433) representing two species and a cross between one of these and a third species. Seed oils of these were analyzed by gas chromatography and reversed-phase high-performance liquid chromatography, and their compositional properties compared with buck-wheat (Fagopyrum esculentum), corn (Zea mays), rice bran (Oryza sativa), soybean (Glycine max L. Merr.), sesame (Sesamum indicum), quinoa (Chenopodium quinoa), and cottonseed (Gossypium hirsutum) oils. All Amaranthus accessions were relatively high in palmitic (21.4–23.8%) and low in oleic (22.8–31.5%) and linolenic (0.65–0.93%) acids when compared to most of the grain and seed oils. The fatty acid composition of Amaranthus accessions K343, K433, and K432 (group I) were different from R149 and RRC1011 (group II) in mono and polyunsaturated fatty acids, but the saturate/unsaturate (S/U) ratios were very similar. All Amaranthus accessions were similar in TAG type, but showed slight differences in percentage. High similarities in UUU, UUS, and USS composition were observed among Amaranthus K343, K433 and K432, and between R149 and RRC1011. The fatty acid compositions of Amaranthus oil (group I) and cottonseed oil were similar, but their TAG compositions were different. The grain and oilseed oils were different from each other and from the Amaranthus accessions oils in terms of fatty acid composition, S/U, and TAG ratios. The UUU, UUS, and USS percentages were very diverse in grain and seed oils. The percentages of squalene in the TAG sample from the Amaranthus accessions were 8.05% in K343, 11.10% in K433, 11.19% in K432, 9.96% in R149, and 9.16% in RRC1011. Squalene was also tentatively identified in quinoa and ricebran oils at levels of 3.39 and 3.10%, respectively.     

Cessation of polyunsaturated fatty acid formation in four selected filamentous fungi when grown on plant oils

Four fungi,Conidiobolus nanodes, Entomophthora exitalis, Mortierella isabellina, andMucor circinelloides, were grown on various oils (triolein, sesame, safflower, linseed, and oil fromM. isabellina) and produced lipids in which the fatty acids were predominantly the same as those of the original staring substrate. Only in the first two cases was there evidence of a small amount of chain elongation and of fatty acid desaturation taking place. The extent of this was only about 10% of that seen in glucose-grown cells. The apparent repression of the fatty acid desaturases and elongases was not reversed by growing cells on glucose and oils as mixed substrates—the fatty acid profiles were the same as when the fungi had grown in oils alone. Neither was the cessation of polyunsaturated fatty acid synthesis due to the presence of nonoil components (NOC) in the oil. Only the NOC from sesame oil affected one single conversion, that of 20∶3n-3 to 20∶4n–6. We conclude that fatty acid desaturase and elongase systems are repressed either partially or completely in a filamentous fungi grown on triacylglycerol oils.     

Fatty acid variation in seed oil amongOcimum species

Content, fatty acid composition, and glyceride profile of oil from seeds of seven basil (Ocimum sp.) chemotypes were determined. The species studied includedO. basilicum, O. canum, O. gratissimum, andO. sanctum. The oil content ranged from 18 to 26%, with triglycerides comprising between 94 and 98% of extracted neutral lipids. The major acylated fatty acids were linolenic (43.8–64.8%), linoleic (17.8–31.3%), oleic (8.5–13.3%), and palmitic acid (6.1–11.0%). Linolenic acid was similar among the fourO. basilicum chemotypes (57–62%), highest inO. canum (65%), and lowest inO. sanctum (44%). Basil seed oil appears suitable as an edible oil or can be used for industrial purposes, and could be processed in the same way as linseed oil. Preliminary calculations estimate that a hectare of basil could produce from 300 to 400 kg of seed oil.     

Fatty acids in echinoidea: Unusualcis-5-olefinic acids as distinctive lipid components in sea urchins

Open tubular gas liquid chromatographic (GLC) analyses of fatty acids from total lipids of 12 species of Echinoidea collected at several locations along the Pacific coast of Japan showed the same unusualcis-5-olefinic acids in all species, i.e.,cis-5-octadecenoic acid (5–18∶1),cis-5-eicosenoic acid (5–20∶1), all-cis-5,11- and 5,13-eicosadienoic acids (5,11- and 5,13–20∶2), allcis-5,11,14-eicosatrienoic acid (5,11,14–20∶3) and all-cis-5,11,14,17-eicosatetraenoic acid (5,11,14,17–20∶4). The structural analysis of partially purified 5,11,14,17–20∶4 was undertaken by reductive ozonolysis with GLC and gas chromatographic-mass spectrometric analyses of the products.¹³C-Nuclear magnetic resonance analyses of the totals and fractions of fatty acid methyl esters from the sea urchin lipids did not show any occurrence of fatty acids having an isolated olefinic bond in the 2, 3 or 4 positions. The 5-olefinic acids were concentrated on the polar lipids rather than neutral lipids. The branched and odd chain fatty acid contents of mud-feeding sea urchins were found to be relatively greater proportions of total fatty acids than in algae feeders.     

Oil content and fatty acid composition of commercially important Turkish fish species

The oil content and fatty acid composition of commercially important Turkish fish species (anchovy,Engraulis encrasicholus; freshwater rainbow trout,Salmo gairdneri; and cultured salmon,S. salar) were determined. Palmitic (16∶0), palmitoleic (16∶1), oleic (18∶1), and docosahexaenoic (22∶6) acids were the most abundant fatty acids in all species. Eicosapentaenoic acid (20∶5) was twice as high in the anchovy oil as in the rainbow trout and salmon oils. Significant quantities of linoleic acid (18∶2) and docosahexaenoic acids (22∶6) were found in both rainbow trout and salmon samples. The individual fatty acid data obtained from rainbow trout and salmon were similar to each other. All three fish species contain high levels of n-3 polyunsaturated fatty acids and would be suitable for inclusion in the formulation of low-fat highly unsaturated diets.     

Positional distribution of Δ5-olefinic acids in triacylglycerols from conifer seed oils: General and specific enrichment in the sn-3 position

Triacylglycerols (TAG) were purified from the storage lipids extracted from the seeds of several conifer species (Taxus baccata, Larix decidua, Sciadopytis verticillata, and Juniperus communis), each species belonging to one of the four families Taxaceae, Pinaceae, Taxodiaceae, and Cupressaceae, respectively. Each species was characterized by a high content of 5,9-18:2, 5,9,12-18:3, 5,11,14-20:3, or 5,11,14,17-20:4 acids, respectively. TAG were partially deacylated with ethylmagnesium bromide, and the resulting 1,2-, 2,3-diacylglycerols (DAG), and 2-monoacylglycerols (MAG) were purified by thin-layer chromatography. 1,2- and 2,3-DAG were further fractionated by chiral column high-performance liquid chromatography of the 3,5-dinitrophenylurethane derivatives. Alternately, TAG were subjected to porcine pancreatic lipase, and the resulting 2-MAG were purified for further analysis. Gas-liquid chromatography of fatty acid methyl esters prepared from the separated DAG and MAG, coupled with appropriate calculations, indicated that the Δ5-olefinic acids, irrespective of the species, chainlengths and number of ethylenic bonds, were considerably enriched in the sn-3 position of TAG where they accounted for ca. 35 to 74 mole% of fatty acids esterified to this position (depending on the initial level of total Δ5-olefinic acids in TAG), which corresponded to 79–94% of Δ5-olefinic acids esterified to the three positions. On the other hand, Δ5-olefinic acids were less than 10% in the sn-2 position and less than 6% in the sn-1 position of TAG. This specific enrichment of Δ5-olefinic acids in the sn-3 position thus appears to be a general characteristic of conifer seed TAG. These results were extended to TAG from the seeds of two pine species (Pinus koraiensis and P. pinaster) that are rich in Δ5-olefinic acids and available commercially on a ton-scale.     

Studies on physicochemical characteristics and fatty acid composition of lipids produced by a strain ofRhodotorula gracilis CFR-1

Rhodotorula gracilis CFR-1 has been evaluated for its potential to produce lipids. The yeast lipids closely resembled palmolein, a liquid fraction of palm oil. It contained 2.3–3% free fatty acids, 64.4% tri-, 23.1% di-, and 6.1% mono-acylglycerols, 94.2% neutral and 5.8% polar lipids. Most abundant fatty acids were C18∶1, C16∶0, C18∶2 and C18∶0 (43.8, 28.5, 13.5 and 4.5%). All fatty acids, irrespective of the levels, followed definite patterns of increase or decrease during the advancement of fermentation. A pincers-shaped curve was obtained when the total saturation and unsaturation were plotted. Use of different glucose and molasses-based media did not show any significant overall effect on saturation (34.4–39.5%) and unsaturation (60.4–65.3%). Desaturation of fatty acids was found to be a metabolic function occurring in the process of cell maturation.     

Lignan analysis in seed oils from fourSesamum species: Comparison of different chromatographic methods

Different chromatographic methods, thin-layer chromatography (TLC), gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS) and normal- and reversed-phase high-performance liquid chromatography (HPLC), were compared for their ability to separate the different lignans present in fourSesamum species,viz., S. indicum Linn.,S. alatum Thonn., S. radiatum Schum & Thonn. andS. angustifolium (Oliv.) Engl. The advantages and limitations of each method are discussed, and a combination of methods is suggested for qualitative analyses. Two-dimensional TLC was found to be a valuable qualitative technique and one-dimensional TLC is useful for preparative purposes. GC is a good supplement for qualitative analysis, but it had many limitations as a quantitative tool—it involves many preparative steps, no suitable internal standard was found to be commercially available and the various lignans had markedly different response factors. GC/MS is a necessary techniqee to confirm the identity of the lignans present. HPLC is a one-step technique suitable for quantitative analyses, and is fast and simple because it involves direct injection of oil solutions. Reversed-phase HPLC was unable to separate sesamolin and sesangolin, but a normal-phase silica column provided satisfactory separation for these two lignans. 2-Episesalation ofS. alatum, however, did not elute from the normalphase column. Once lignans are identified, a relevant HPLC method can be used for quantitative analyses. Sesamin was present in large amounts inS. radiatum, in considerable amounts inS. indicum andS. angustifolium, and in small amounts inS. alatum. Sesamolin occurred in considerable amounts inS. indicum andS. angustifolium, but only in small amounts in the other two wild species studied.Sesamum alatum was characterized by high amounts of 2-episesalatin, andS. angustifolium was characterized by high levels of sesangolin.     

Conifer seeds: Oil content and fatty acid composition

The seed oils from twenty-five Conifer species (from four families—Pinaceae, Cupressaceae, Taxodiaceae, and Taxaceae) have been analyzed, and their fatty acid compositions were established by capillary gas-liquid chromatography on two columns with different polarities. The oil content of the seeds varied from less than 1% up to 50%. Conifer seed oils were characterized by the presence of several Δ5-unsaturated polymethylene-interrupted polyunsaturated fatty acids (Δ5-acids) with either 18 (cis-5,cis-9, 18∶2,cis-5,cis-9,cis-12 18∶3, andcis-5,cis-9,cis-12,cis-15 18∶4 acids) or 20 carbon atoms (cis-5,cis-11 20∶2,cis-5,cis-11,cis-14, 20∶3, andcis-5,cis-11,cis-14,cis-17 20∶4 acids). Pinaceae seed oils contained 17–31% of Δ5-acids, mainly with 18 carbon atoms. The 20-carbon acids present were structurally derived from 20∶1n-9 and 20∶2n-6 acids. Pinaceae seed oils were practically devoid of 18∶3n-3 acid and did not contain either Δ5-18∶4 or Δ5-20∶4 acids. Several Pinaceae seeds had a Δ5-acid content higher than 50 mg/g of seed. The only Taxaceae seed oil studied (Taxus baccata) had a fatty acid composition related to those of Pinaceae seed oils. Cupressaceae seed oils differed from Pinaceae seed oils by the absence of Δ5-acids with 18 carbon atoms and high concentrations in 18∶3n-3 acid and in Δ5-acids with 20 carbon atoms (Δ5-20∶3 and Δ5-20∶4 acids). Δ5-18∶4 Acid was present in minute amounts. The highest level of Δ5-20∶4 acid was found inJuniperus communis seed oil, but the best source of Δ5-acids among Cupressaceae wasThuja occidentalis. Taxodiaceae seed oils had more heterogeneous fatty acid compositions, but the distribution of Δ5-acids resembled that found in Cupressaceae seed oils. Except forSciadopytis verticillata, other Taxodiaceae species are not interesting sources of Δ5-acids. The distribution profile of Δ5-acids among different Conifer families appeared to be linked to the occurrence of 18∶3n-3 acid in the seed oils.     

The seed fatty acid composition and the distribution of Δ5-olefinic acids in the triacylglycerols of some taxares (Cephalotaxus and Podocarpus)

The fatty acid compositions of the seeds from four Cephalotaxus species or varieties (plum yews; Cephalotaxaceae) and two Podocarpus species (podocarps; Podocarpaceae) have been established. These compositions were compared with those previously published for some Taxaceae species (Taxus and Torreya). Cephalotaxaceae, Podocarpaceae, and Taxaceae belong to the Taxares suborder. Δ5-Olefinic acids are present in the seed lipids from all species analyzed. In Cephalotaxus, Podocarpus, and Torreya, the prominent Δ5-olefinic acid that occurs is the trienoic acid 5,11,14–20:3 (sciadonic) acid, comprising from 6.7 to 26.4% of total fatty acids. In these species, the Δ5,11 structure is largely favored over the Δ5,9 structure: the 5,9–18:2 (taxoleic) and 5,9,12–18:3 (pinolenic) acids are at the limit of detection, in contrast to Taxus and most Pinaceae species, where these two Δ5-olefinic acids generally predominate. 14-Methylhexadecanoic acid, an habitual though minor component of Pinaceae and Ginkgo biloba seed lipids, could not be detected in Cephalotaxus species studied here and was tentatively identified in trace amounts only in one Podocarpus species. In addition to sciadonic acid, Cephalotaxus and Podocarpus seeds are characterized by unusually high amounts of 11,14–20:2 acid, in the range of 3.1–12.0%. This contrasts with most of the 170 species of conifers analyzed so far (from the families Pinaceae, Cupressaceae, Taxodiaceae, Taxaceae, and Sciadopityaceae, which belong to the Pinares suborder), where this acid is generally ≤2%. A close resemblance between Torreya grandis and three of the Cephalotaxus species analyzed might be indicative of some phyletic relationship between the families Cephalotaxaceae and Taxaceae. ¹³C nuclear magnetic resonance spectroscopy of the seed oils from C. drupaceae and P. andinus has shown that Δ5-olefinic acids are apparently excluded from the internal position of triacylglycerols, which is a characteristic common to all Coniferales species analyzed so far, and consequently of great antiquity.     

cis-5-olefinic unusual fatty acids in seed lipids of gymnospermae and their distribution in triacylglycerols

Open-tubular gas chromatographic analysis of fatty acids in the lipids from the seeds of 20 species of Gymnospermae showed that they all contained nonmethylene-interrupted polyenoic (NMIP) acids as minor components and palmitic, oleic, linoleic and α-linolenic acids as major components. The NMIP acids have an additional 5,6-ethylenic bond in ordinary plant unsaturated fatty acids and the following C₂ elongation acids:cis-5,cis-9-octadecadienoic acid (5,9–18∶2) (I); 5,9,12–18∶3 (II); 5,9,12,15–18∶4, 5,11–20∶2, 5,11,14–20∶3 (III); and 5,11,14,17–20∶4 (IV). The main NMIP acids found in neutral lipids are I in two species ofTaxus, II in seven species of Pinaceae, III in two species of Podocarpaceae,Torreya nucifera, Cycas revoluta, andGinkgo biloba, and III and IV in each of three species of Taxodiaceae, and Cupressaceae. The polar lipids constitute the minor fraction of seed lipids in general. The content and composition of NMIP acids in these lipids differe considerably from those in neutral lipids. Analysis of the partial cleavage products of triacylglycerols showed that the NMIP acids distribute mainly in the 1,3-position.     

Influence of diet on fatty acids of three subtropical fish, subfamily caesioninae (Caesio diagramma and C. tile) and family siganidae (Siganus canaliculatus)

The total lipid and fatty acid compositions of tissues and the stomach contents of three subtropical marine fish species, subfamily Caesioninae, Caesio diagramma and C. tile, and family Siganidae Siganus canaliculatus, were investigated to clarify the differences between these species. Triacylglycerols (TAG) were the dominant depot lipids of the three species, whereas wax esters were found as a minor component. In particular, muscle lipids were found to contain mainly glycerol derivatives such as TAG and phospholipids. The major fatty acids identified in the three species were 16∶0, 18∶0, 18∶1n−9, and 22∶6n−3 (docosahexaenoic acid, DHA). In addition, noticeable levels of 16∶1n−7, 18∶1n−7, 20∶4n−6 (arachidonic acid, AA), and 20∶5n−3 (eicosapentaenoic acid) were found. DHA was the most abundant polyunsaturated fatty acid (PUFA) in the muscle and viscera lipids of the three species. The high DHA levels in the lipids of all the organs were found to be higher than those of the lipid extracted from the stomach contents of the three fishes. In addition, the specimens of S. canaliculatus contained significantly higher levels of AA in its tissues than did the other two species. A high AA content is unusual since such high levels of n−6 PUFA are rarely found in higher marine organisms. These levels may be due to its characteristic feeding pattern, because S. canaliculatus prefer and mainly feed on seaweed, which often contains high amounts of n−6 PUFA, such as linoleic acid (18∶2n−6) and AA.     

Effect of extraction methods on lipid yield and fatty acid composition of lipid classes containing γ-linolenic acid extracted from fungi

The effect of extraction procedures on the lipid yield and fatty acid composition of total lipid and main lipid structures (phospholipids, diacylglycerols, triacylglycerols, free fatty acids, and sterol esters) of fungal biomass (Mucor mucedo CCF-1384) containing γ-linolenic acid (GLA) was investigated. Seventeen extraction methods, divided into three groups, were tested: six with chloroform/methanol, five with hexane/alcohols, and six with common solvents or mixtures. The chloroform/methanol procedure (2∶1) was selected as standard, where lipid yield (TL/DCW, total lipid per dry cell weight) was 17.8%, considered to be 100% of lipids present. All chloroform/methanol extractions yielded more than 83% recorvey of lipids. Use of hexane/isopropanol solvent systems led to a maximum of 75% recovery. The best lipid yield was achieved by a two-step extraction with ethanol and hexane (120%). Extraction efficiency of the other solvent systems reached a maximum of 73%. Triacylglycerols were the main structures of lipid isolated; only methanol-extracted lipid contained 58.5% phospholipids. The fatty acid content of total recovered lipid was variable and depended on both the lipid class composition and the solvent system. GLA concentrations in total lipids isolated by hexane/alcohol procedures (7.3–10.7%) are comparable with classical chloroform/methanol systems (6.5–10.0%). The maximal GLA yield was obtained with chloroform/methanol/n-butanol/water/0.1 M ethylenediaminetetraacetic acid (EDTA) (2∶1∶1∶1∶0.1, by vol) and after two-step extraction with ethanol and hexane (14.3 and 13.7 g GLA/kg DCW, respectively). The highest GLA content was analyzed in the phospholipid fraction (16.1%) after using chloroform/methanol/n-butanol/water/0.1 M EDTA (2∶1∶1∶1∶0.1, by vol). Remarkably low concentrations of polyunsaturated fatty acids were determined in the free fatty acid fraction.     

Characteristic profiles of lipid classes,fatty acids and triacylglycerol molecular species of peas (Pisum sativum L.)

Seed oils from four legume cultivars of Pisum sativum, grown in Japan, were extracted and classified by thin‐layer chromatography (TLC) into seven fractions: hydrocarbons (HC; 0.5–0.9 wt‐%), steryl esters (SE; 0.8–2.4 wt‐%), triacylglycerols (TAG; 31.2–40.3 wt‐%), free fatty acids (FFA; 1.3–2.7 wt‐%), 1,3‐diacylglycerols (1,3‐DAG; 1.0–1.8 wt‐%), 1,2‐diacylglycerols (1,2‐DAG; 1.0–2.2 wt‐%) and phospholipids (PL; 52.2–61.3 wt‐%). All lipid samples had high amounts of total unsaturated fatty acids, representing 75.0–84.3 wt‐% for TAG and PL. Molecular species and fatty acid distributions of TAG, isolated from the total lipids in the peas, were analyzed by a combination of argentation‐TLC and GC. Eighteen different molecular species were detected. With a few exceptions, the main TAG components were SMD (7.5–10.3 wt‐%), M₂D (8.0–8.9 wt‐%), SD₂ (12.0–18.3 wt‐%), SMT (9.8–11.0 wt‐%), MD₂ (12.0–20.3 wt‐%), SDT (9.7–10.8 wt‐%), M₂T (2.5–7.3 wt‐%) and D₃ (14.5–15.2 wt‐%) (where S denotes a saturated fatty acid, M denotes a monoene, D denotes a diene, and T denotes a triene). It seems that the four cultivars were highly related to each other based on the fatty acid composition of the TAG as well as the distribution profiles in the different TAG molecular species. In general, these results suggest that there are no essential differences (p >0.05) in the oil components among the four cultivars.