Composition and seasonal variation of fatty acids of <Emphasis Type="Italic">Diplodus vulgaris</Emphasis> L. from the Adriatic Sea

Muscle tissue from the common two-banded sea bream Diplodus vulgaris L. originating from the Adriatic Sea, Croatia, was analyzed. The FA composition of neutral (TAG) and polar (PE, PC, PI/PS) lipid classes was determined, as well as the lipid and water contents during winter and summer periods. Both the total lipid and water contents were higher in the winter period. We identified 16 different FA. The major constituents of the total FA in both seasons were saturates: palmitic (16∶0) and stearic acids (18∶0); monoenes: oleic (18∶1n−9) and palmitoleic acids (16∶1n−7); and polyunsaturates: arachidonic acid (20∶4n−6), EPA (20∶5n−3), and DHA (22∶6n−3), but their amounts and ratios differed significantly between the two seasons and between lipid fractions. The FA composition showed a noticeable pattern of seasonality that reflected fluctuations mainly in TAG. The diminution of the monounsaturated FA content in the summer was clearly followed by an increase in PUFA content. Diplodus vulgaris is a good source of natural n−3 PUFA and would therefore be suitable for inclusion in highly unsaturated low-fat diets.     

Enzymatic fractionation and enrichment of n−9 PUFA

A single-cell oil from a Mortierella alpina mutant (TGM17 oil) contains n−9 PUFA: 14.3 wt% 6,9-octadecadienoic acid (18∶2n−9; n−9 LnA) and 17.1 wt% Mead acid (20∶3n−9; MA). Lipase screening indicated that Pseudomonas aeruginosa lipase acted strongly on n−9 LnA and weakly on MA, and Candida rugosa lipase acted weakly on the two PUFA. Hence, fractionation and enrichment of the two FA were conducted with the lipases. The first step was selective hydrolysis of IGM17 oil with P. aeruginosa lipase. The hydrolysis fractionated the oil into FFA containing 20.4 wt% n−9 LnA and 6.3 wt% MA, and acylglycerols containing 10.7 wt% n−9 LnA and 23.7 wt% MA. The FFA fraction was used for preparation of n−9 LnA-rich FFA. After removal of saturated FA, the FFA were esterified with lauryl alcohol (LauOH) using C. rugosa lipase. Two selective esterifications increased the n−9 LnA content to 54.0 wt% with 38.2% recovery of the initial content of TGM17 oil. The acylglycerol fraction obtained in the hydrolysis with P. aeruginosa lipase was used for preparation of MA-rich FFA. The acylglycerol fraction was hydrolyzed under alkaline conditions, and saturated FA were eliminated by urea adduct fractionation. Two selective esterifications of the FFA with LauOH increased the MA content to 60.2 wt% with 53.5% recovery. Thus, the two-step enzymatic process was effective for fractionation and enrichment of n−9 LnA and MA.     

Positional distribution of 24∶6(n−3) in triacyl-sn-glycerols from flathead flounder liver and flesh

This paper presents the positional distribution of very long-chain fatty acids, 24∶6(n−3), in triacyl-sn-glycerols (TG) of flathead flounder (Hippoglossoides dubius). Each of the liver and flesh TGs was subjected to the stereospecific analysis. The liver TGs contained 24∶6(n−3) at concentrations of 1.5, 1.2 and 1.7 mole % in thesn-1,sn-2 andsn-3 positions, respectively, and the flesh TGs had 9.0, 7.8 and 7.1 mole % in thesn-1,sn-2 andsn-3 positions, respectively. This fatty acid was distributed almost evenly among the three positions of the TGs. No preference for thesn-2 position was observed in contrast to the general tendency for the distribution of longer-chain polyunsaturated fatty acids, such as 22∶6(n−3), 22∶5(n−3) and 20∶5(n−3). There was essentially no difference in the positional distributions of the liver and flesh TGs. The results obtained in this study give new fundamental information to the investigation of very long-chain fatty 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.     

New 17-Methyl-13-Octadecenoic and 3,16-Docosadienoic Acids from the Sponge <Emphasis Type="Italic">Polymastia penicillus</Emphasis>

The phospholipid fatty acid composition of the North-East Atlantic sponge Polymastia penicillus (South Brittany, France) was investigated. Sixty fatty acids (FA) were identified as methyl esters (FAME) and N-acyl pyrrolidides (NAP) by gas chromatography–mass spectrometry (GC/MS), including eight Δ5,9 unsaturated FA and three long-chain 2-hydroxylated FA. The major phospholipid FA were palmitic (14.3% of the total FA mixture), vaccenic (12.7%), 15(Z)-docosenoic (13.4%) and 5(Z),9(Z)-hexacosadienoic (13.3%) acids. In addition to the iso- and anteiso-branched saturated FA, several unusual short-chain branched saturated FA were identified. In addition to the known Δ5,9 FA, and interestingly regarding their identification by GC–MS as N-acyl pyrrolidides, was the co-occurrence of unusual FA possessing a Δ3, Δ4 and Δ5 double bond such as iso-4-pentadecenoic, iso-5-heptadecenoic, anteiso-5-heptadecenoic and two new compounds, not hitherto found in nature, namely 17-methyl-13-octadecenoic (0.8%) and 3,16-docosadienoic (1.1%) acids.     

Fatty acids, tocols, and carotenoids in pulp oil of three sea buckthorn species (Hippophae rhamnoides, H. salicifolia, and H. tibetana) grown in the Indian Himalayas

Sea buckthorn berries from Hippophae rhamnoides, H. tibetana, and H. salicifolia were collected from the cold deserts of the Himalayas (Lahaul, Ladakh, and Spiti; India) and characterized in terms of the FA, carotenoid, tocopherol, and tocotrienol composition in their pulp oil. These varied from species to species. Total carotenoids ranged from 692 to 3420 mg/kg in pulp oils of fresh berries, and total tocols, from 666 to 1788 mg/kg. Hippophae salicifolia berries contained substantially lower amounts of pulp oil, with lower levels of carotenoids and tocopherols. There was little difference in the proportion of individual tocols in pulp among the three species. α-Tocopherol alone constituted 40–60% of total pulp tocols in berries. Pulp oils had palmitoleic acid (32–53%) as the most abundant FA followed by palmitic (25–35%), oleic (8–26%), linoleic (5–16%), and linolenic (0.6–2.6%) acids, with the highest deviation observed in the proportion of palmitoleic acid in these berries. Hippophae rhamnoides and H. tibetana contained the highest amount of the lipophilic carotenoids and tocols. Hippophae salicifolia berries had higher amounts of lipophobic constituents such as vitamin C and flavonols.     

Borago officinalis oil: Fatty acid fractionation by immobilized Candida rugosa lipase

γ-Linolenic acid (Z,Z,Z-6,9,12-octadecatrienoic acid), a very important polyunsaturated fatty acid is found in the free fatty acid fraction prepared by the hydrolysis of borage oil. Our aim was to enrich this fraction in γ-linolenic acid using selective esterification. Candida rugosa lipase was used as catalyst after immobilization on the following ion-exchange resins: Amberlite IRC50, IRA35, IRA93, and Duolite A7, A368, A568. In every case, immobilization modified the lipae’s specificity: palmitic, stearic, oleic, and linoleic acids were preferentially esterified compared to γ-linolenic acid, thus allowing a γ-linolenic acid enrichment of 3.0.     

Hybrid <Emphasis Type="Italic">Hibiscus</Emphasis> seed oil compositions

The seeds of cultivated Hibiscus spp. were extracted with supercritical carbon dioxide, and the resulting extracts were analyzed to identify the major TG components as the corresponding FAME. The seed oils were composed predominantly of oleic and linoleic FA (69.6–83.4%) with lesser amounts of palmitic acid (14.8–27.0%). Minor amounts of C14, C18, and C20 saturated FA were also detected. The oil content of the seeds was determined to be between 11.8 and 22.1 wt% for hybrid varieties and between 8.9 and 29.5 wt% for the native species from which the hybrid varieties were developed. The protein content of the defatted seed meal averaged 20% for the hybrid varieties. The composition of the extracted hibiscus seed oils suggests potential edible applications.     

Red maple (Acer rubrum) inhibits feeding by beaver (Castor canadensis)

At many beaver (Castor canadensis) sites at Allegany State Park in New York State, red maple (Acer rubrum) is the only or one of the few tree species left standing at the ponds' edges. The relative palatability of red maple (RM) was studied in three ways. (1) At seven beaver sites, the available and utilized trees were recorded and an electivity index (E) computed. Of 15 tree species, RM ranked second or fourth lowest. (2) In experiment I, RM, sugar maple (A. saccharum, SM), and quaking aspen (Populus tremuloides) logs were presented cafeteria style at 10 colonies. RM was the least preferred. (3) Bark of RM was extracted with solvents. Aspen logs were painted (experiment II) or soaked (experiment III) with this RM extract and presented to beaver cafeteria-style, along with aspen and RM controls. This treatment rendered aspen logs less palatable, indicating that a chemical factor had been transferred.     

<Emphasis Type="Italic">Santalum </Emphasis><Emphasis Type="Italic">insulare</Emphasis> Acetylenic Fatty Acid Seed Oils: Comparison within the <Emphasis Type="Italic">Santalum</Emphasis> Genus

The sandalwood kernels of Santalum insulare (Santalaceae) collected in French Polynesia give seed oils containing significant amounts of ximenynic acid, E-11-octadecen-9-oic acid (64–86%). Fatty acid (FA) identifications were performed by gas chromatography/mass spectrometry (GC/MS) of FA methyl esters. Among the other main eight identified fatty acids, oleic acid was found at a 7–28% level. The content in stearolic acid, octadec-9-ynoic acid, was low (0.7–3.0%). An inverse relationship was demonstrated between ximenynic acid and oleic acid using 20 seed oils. Results obtained have been compared to other previously published data on species belonging to the Santalum genus, using multivariate statistical analysis. The relative FA S. insulare composition, rich in ximenynic acid is in the same order of those given for S. album or S. obtusifolium. The other compared species (S. acuminatum, S. lanceolatum, S. spicatum and S. murrayanum) are richer in oleic acid (40–59%) with some little differences in linolenic content.     

Epoxidation ofLesquerella andLimnanthes (Meadowfoam) oils

Lesquerella gordonii (Gray) Wats andLimnanthes alba Benth. (Meadowfoam) are species being studied as new and alternative crops. Triglyceride oil from lesquerella contains 55–60% of the uncommon 14-hydroxy-cis-11-eicosenoic acid. Meadowfoam oil has 95% uncommon acids, includingca. 60%cis-5-eicosenoic acid. Both oils are predominantly unsaturated (3% saturated acids), and have similar iodine values (90–91), from which oxirane values of 5.7% are possible for the fully epoxidized oils. Each oil was epoxidized withm-chloro-peroxybenzoic acid, and oxirane values were 5.0% (lesquerella) and 5.2% (meadowfoam). The epoxy acid composition of each product was examined by gas chromatography of the methyl esters, which showed that epoxidizedL. gordonii oil contained 55% 11,12-epoxy-14-hydroxyeicosanoic acid, and epoxidized meadowfoam oil contained 63% 5,6-epoxyeicosanoic acid, as expected for normal complete epoxidation. Mass spectrometry of trimethylsilyloxy derivatives of polyols, prepared from the epoxidized esters, confirmed the identity of the epoxidation products and the straightforward nature of the epoxidation process. Synthesis and characterization of these interesting epoxy oils and derivatives are discussed.     

Enzymatic synthesis of l-menthyl esters in organic solvent-free system

l-Menthol has been widely used as a food additive and an ingredient of cosmetics, and it is esterified to moderate the strong flavor. We attempted esterification of l-menthol with long-chain unsaturated fatty acid in an organic solvent-free enzymatic system. Commercially available lipases were screened, and Candida rugosa lipase was selected as a catalyst. Several factors affecting the esterification were investigated, and the reaction conditions were determined as follows: A reaction mixture of l-menthol/fatty acid (1:3, mol/mol), 30% water, and 700 units of the lipase per gram of reaction mixture was incubated at 30°C with stirring. After 24 h under these conditions, the esterification extents of l-menthol with oleic, linoleic, and α-linolenic acids reached 96, 88, and 95%, respectively. The structure of the esterified product was confirmed by mass, infrared, and nuclear magnetic resonance spectroscopies. Bacause Candida lipase acted strongly on l-menthol and very weakly on d-menthol, dl-menthol was esterified with oleic acid under the same conditions. The reaction showed high enantioselectivity; the enantiomeric ratio (E) was 31, and enantiomeric excess (ee) of l-menthyl oleate reached 88% after 32 h.     

Genetic diversity for lipid content and fatty acid profile in rice bran

Rice (Oryza sativa L.) bran contains valuable nutritional constituents, which include lipids with health benefits. A germplasm collection consisting of 204 genetically diverse rice accessions was grown under field conditions and evaluated for total oil content and fatty acid (FA) composition. Genotype effects were highly statistically significant for lipid content and FA profile (P<0.001). Environment (year) significantly affected oil content (P<0.05), as well as stearic, oleic, linoleic, and linolenic acids (all with P<0.01 or lower), but not palmitic acid. The oil content in rice bran varied relatively strongly, ranging from 17.3 to 27.4% (w/w). The major FA in bran oil were palmitic, oleic, and linoleic acids, which were in the ranges of 13.9–22.1, 35.9–49.2, and 27.3–41.0%, respectively. The ratio of saturated to unsaturated FA (S/U ratio) was highly related to the palmitic acid content (r ²=0.97). Japonica lines were characterized by a low palmitic acid content and S/U ratio, whereas Indica lines showed a high palmitic acid content and a high S/U ratio. The variation found suggests it is possible to select for both oil content and FA profile in rice bran.     

Characterization and supercritical carbon dioxide extraction of walnut oil

Walnut (Juglans regia L.) oil was extracted with compressed carbon dioxide (CO₂) in the temperature range of 308 to 321 K and in the pressure range of 18 to 23.4 MPa. The influence of particle size was also studied at a superficial velocity of 0.068 cm/s, within a tubular extractor of 0.2 L capacity (cross-sectional area of 16.4 cm²). FFA, sterol, TAG, and tocopherol compositions were not different from those of oil obtained with n-hexane. The main FA was linoleic acid (56.5%), followed by oleic acid (21.2%) and linolenic acid (13.2%). The main TAG was LLL (linoleic, linoleic, linoleic) (24.4%), followed by OLL (oleic, linoleic, linoleic) (19.6%) and LLLn (linoleic, linoleic, linolenic) (18.4%). The main component of sterols was β-sitosterol (85.16%), followed by campesterol (5.06%). The amount of cholesterol was low (0.31 and 0.16% for oils extracted by n-hexane and supercritical fluid extraction, respectively. The CO₂-extracted oil presented a larger amount of tocopherols (405.7 μg/g oil) when compared with 303.2 μg/g oil obtained with n-hexane. Oxidative stability determined by PV and the Rancimat method revealed that walnut oil was readily oxidized. Oil extracted by supercritical CO₂ was clearer than that extracted by n-hexane, showing some refining. A central composite, nonfactorial design was used to optimize the extraction conditions using the software Statistica, Version 5. The best results were found at 22 MPa, 308 K, and particle diameter (Dp) −0.1 mm.     

Fatty Acid Composition and Oil Yield in Fruits of Five <Emphasis Type="Italic">Arecaceae</Emphasis> Species Grown in Cuba

The present study targeted the whole-fruit oil yield and fatty acid composition from five of the most abundant Arecaceae species grown in Cuba. The oil yields (% dry weight), determined by the Soxhlet extraction technique with hexane, were 25.5, 5.3, 6.9, 5.4, and 6.4% for Roystonea regia, Colpothrinax wrightii, Sabal maritima, Sabal palmetto and Thrinax radiata, respectively. The free fatty acid (FFA) content varied from 2.7 to 6.8%. Fatty acid (FA) profiles of the oils indicated that lauric acid (13.7–44.4%), myristic acid (9.4–22.4%) and palmitic acid (9.2–17.1%) as major saturated FA; whereas oleic acid (9.6–42.7%) and linoleic acid (9.3–17.0%) as major unsaturated FA. R. regia fruit seemed the most promising among Arecaceae grown in Cuba because of its high oil yield and low oil FFA content.     

Bioconversion of n−3 and n−6 PUFA by <Emphasis Type="Italic">Clavibacter</Emphasis> sp. ALA2

Clavibacter sp. ALA2 oxidized n−3 and n−6 PUFA into a variety of oxylipins. Structures of products converted from EPA and DHA were determined as 15,18-dihydroxy-14,17-epoxy-5(Z),8(Z),11(Z)-eicosatrienoic acid and 17,20-dihydroxy-16,19-epoxy-4(Z),7(Z),10(Z),13(Z)-docosatetraenoic acid by GC-MS and NMR analyses. In contrast, γ-linolenic acid and arachidonic acid were converted to diepoxy bicyclic FA, tetrahydrofuranyl monohydroxy FA, and trihydroxy FA. Thus, the structures of bioconversion products were different between n−3 and n−6 PUFA. Furthermore, strain ALA2 placed hydroxy groups and cyclic structures at the same position from the ω-terminal despite the number of carbons in the chain and the double bonds in the PUFA.     

NIR reflectance spectroscopic analysis of the FA composition in sesame (<Emphasis Type="Italic">Sesamum indicum</Emphasis> L.) seeds

The feasibility of using NIR reflectance spectroscopy to estimate the FA composition of sesame seed (Sesamum indicum L.) samples from the National Institute of Crop Science of Japan and from Myanmar was examined. Multiple linear-regression analyses of NIR sepctral data and chemical data for whole seeds were carried out to develop calibration equations for predicting the proportion of each of the four major FA in sesame seeds from the total FA composition. The SE of prediction (SEP) was 0.616% for palmitic acid, 0.348% for stearic acid, 1.051% for oleic acid, and 0.826% for linoleic acid. This NIR method provides a simple, rapid, and nondestructive means of estimating the FA composition of sesame seeds for breeding selection, regardless of the color of the sesame seed coats. However, the proportions of palmitic and stearic acids could not be reliably measured because their SEP were almost as great as the SD of their concentrations in the set of prediction samples. The relationship between NIR spectral patterns and the FA composition of sesame seeds also was examined. The correlation coefficient calculated for the standardized second-derivative NIR spectral readings at 1708 nm and the percentages of linoleic acid was −0.830. A rough estimate of the proportion of linoleic acid in the total FA composition of sesame seeds could be obtained even with single sesame seeds, except for those with a black coat, based on NIR spectral pattern analysis using the wavelength assignments of linoleic acid.     

Varietal and crop year effects on lipid composition of walnut (Juglans regia) genotypes

The FA, unsaponifiable, and volatile constituents of oil from three walnut varieties from two consecutive crop years were studied. The walnut oils (WO) were rich in PUFA and low in saturated FA. The tocopherol fraction consisted mainly of γ-tocopherol. High contents of β-sitosterol were found, together with campesterol and Δ⁵-avenasterol in similar amounts. Methylsterols present in WO were identified as cycloartenol, cyclolaudenol, cycloeucalenol, and 24-methylenecycloartanol. The hydrocarbon fraction was characterized by the predominance of C₁₄–C₂₀ n-alkanes. The major volatiles were aldehydes produced through the linoleic acid oxidative pathway. FA, methylsterols, and some hydrocarbons presented statistically significant differences among varieties. Most of this variation was due to the genotype. The Franquette variety was noteworthy by its higher oil and oleic acid contents. In contrast, tocopherols and volatile compounds showed minor differences among varieties; they were strongly influenced by the crop year. Chemical data were subjected to principal component analysis. The parameters that gave the greatest discrimination between the walnut varieties were oleic and linolenic acids, tetradecane, eicosane, tetracosane, cycloartenol, and 24-methylenecycloartanol. These components presented the major varietal influences and could be useful to determine the identity of walnut genotypes.     

Characterization of oil exhibiting high γ-linolenic acid from a genetically transformed canola strain

The seed oil from a genetically transformed canola (Brassica napus) containing 43% (w/w) of γ-linolenic acid (G, 18∶3n−6), 22% linoleic acid (L, 18∶2n−6), and 16% oleic acid (O, 18∶1n−9) was evaluated. In this high γ-linolenic acid canola oil (HGCO), the predominant 18∶3n−6-containing triacylglycerol (TG) molecular species were GGL (23%), GLO (20%), and GGG (11%). In the total TG, approximately 75% of the 18∶3n−6 was located at the sn-1,3 positions, while only 34% of linoleic acid was at the sn-1,3 positions. The GGL molecular species of HGCO contained approximately equal amounts of GLG and GGL positional isomers, while the GLO molecular species had 95% GOL and 5% GLO isomers. The general characteristics and the tocopherol and phytosterol contents were mostly similar between HGCO and nontransformed canola oil. No detectable amounts of amino acids and nucleotides were observed in the HGCO.     

NMR,GC–MS and ESI-FTICR-MS Profiling of Fatty Acids and Triacylglycerols in Some Botswana Seed Oils

In the search for non-traditional seed oils, physicochemical parameters, fatty acid (FA) and triacylglycerol (TAG) profiles for five Botswana seed oils, obtained by Soxhlet extraction, were determined. GC–MS and ¹H-NMR analyses showed the FA profiles for mkukubuyo, Sterculia africana, and manketti, Ricinodendron rautanenii, seed oils dominated by linoleic and oleic acids, 26.1, 16.7 and 51.9, 24.4%, respectively, with S. africana containing significant amounts of cyclic FAs (19.9%). Mokolwane, Hyphaene petersiana, seed oil was typically lauric; 12:0 and 14:0 acids were 25.9 and 13.4%, respectively. Morama, Tylosema esculentum, seed oil resembled olive oil; 18:1 (47.3%) and 18:2 (23.4%) acids dominated. Moretologa-kgomo, Ximenia caffra, seed oil had 45.8% of 18:1 FA, plus significant amounts of very long chain FAs: 26:1 (5.8%), 28:1 (13.9%), 30:1 (3.9%), and acetylenic acids, 9a-18:1 (1.5%) and 9a, 11t-18:2 (16.0%). TAG classes and regiochemistry were determined with ESI-FTICR-MS, and ¹³C-NMR spectra, respectively. Morama showed seven major TAG classes with C54:4 and C54:3 dominating; mokolwane had 16 major classes with C32:0, C38:0 and C42:2 dominating; manketti had 11 major classes with C54:7, C54:6 and C54:4 dominating; mkukubuyo had 12 major classes with C52:4, C52:3 and C54:4 dominating; moretologa-kgomo had 30 major TAG classes with C64:5, C64:3 and C62:3 dominating. Saturated FAs were generally distributed over the sn-1(3) position for morama, manketti, and moretologa-kgomo but at the sn-2 position for mokolwane and mkukubuyo. These findings indicate that morama and manketti seed oils can be developed for food uses, whilst moretologa-kgomo and mkukubuyo seed oils only for nonfood uses.