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.     

Fungi pathogenic to insects: III. Neutral and polar lipids ofEntomophthora coronata

The neutral and polar lipid composition ofEntomophthora coronata was determined qualitatively. The fungus was grown on a chemically nondefined medium (Sabouraud dextrose yeast extract) and a chemically defined medium for a period up to 26 days. The lipids were characterized by thin-layer, column, gas chromatography, and selective sprays,³²P-labeling, and mass spectrometry. The neutral lipids consist of monoglycerides, diglycerides, cholesterol, free fatty acids, triglycerides, and cholesteryl esters. The polar lipids consist of phospholipids (phosphatidyl ethanolamine, phosphatidyl choline, lysophosphatidyl ethanolamine, lysophosphatidyl choline, and spingomyelin), a number of glycolipids including cerebrosides, and many unrecognizable lipids, most of which are present in trace amounts. The cerebrosides and spingomyelin are present in significant amounts, and their concentration increased with age of the culture. The major fatty acids (>10%) of the total, neutral, and polar lipids of the mycelia are 14∶0, 16∶0, 18∶1, 18∶3(γ), and 24∶1. The polar lipids of total culture (unsaturation index 0.88) and of the conidia (unsaturation index 1.48) are considerably more unsaturated than the corresponding neutral lipids (unsaturated index 0.50 and 0.49). The mycelial polar lipids, compared to the neutral lipids, possess less 14∶0 and 18∶1 but contain a greater percentage of 16∶0, 18∶2, 18∶3(γ), 24∶0, and 24∶1. The major fatty acid of the conidia (>10%) are 13∶0, 14∶0, 18∶1, 18∶2, 18∶3(γ), and 20∶4. Their polar lipids have a higher proportion of 18∶2, 18∶3(γ), and 20∶4. The cerebrosides possess 24.1 in high relative proportion (30.1%). Presented at the AOCS Meeting, Atlantic City, October 1971.     

Influence of dietary fatty acids on the glycerophospholipid composition in organs of cod (gadus morhua)

Cod (mean start weight of 26 g) were fed three diets for 15 months, each based on a dry pellet coated at a level of 9g/100 g with soybean oil, capelin oil or sardine oil. The fatty acid compositions of neutral lipids and four glycerophospholipids of white muscle, liver, gills and heart were determined. The fatty acid composition of dietary lipids influenced the composition of neutral lipids in all organs. Linoleic acid (18∶2n−6) from soybean oil was selectively incorporated into phosphatidylcholine of the four tissues. Similar levels of 20∶5n−3 and 22∶6n−3 in phosphatidylcholine and phosphatidylethanolamine were found in all organs from cod fed capelin oil and sardine oil in spite of highly differentiated feed fatty acid levels. The polyunsaturated fatty acid (PUFA) composition of phosphatidylinositol was least influenced by dietary lipids. The preferred monoenic fatty acid in phospholipids of cod was 18∶1n−9, independent of dietary intake, whereas the longer chain monoenoic acids seemed to be preferentially catabolized. The results suggest that 20∶4n−6 as well as 20∶5n−3 and 22∶6n−3 fatty acids are essential for cod.     

Lipid components and enzymatic hydrolysis of lipids in muscle of Chinese freshwater fish

The lipid and fatty acid composition of muscle of 10 species of freshwater fish obtained from a market of Shanghai City was examined. Total lipids (TL) ranged over 0.9–4.7% of muscle for all samples. The content of triacylglycerol (TG) in muscle ranged over 0.2–3.4% and that of polar lipids (PL) was 0.5–1.3%. Differences of TL content were dependent on TG contents. The predominant important fatty acids (>10% of the total fatty acids in TL) were 16∶0 and 18∶1n−9 with some 16∶1n−7, 18∶2n−6, and 22∶6n−3. The polyunsaturated fatty acids (PUFA) content was 10.2–43.4%, and especially Chinese sea bass contained above 20% of 22∶6n−3 in the total fatty acids. There were higher levels of PUFA such as 20∶5n−3 and 22∶6n−3 in PL than in neutral lipids. Muscle of the silver carp was stored at 20°C, and changes of lipid classes during storage were examined. Free fatty acids increased, and PL decreased during storage. This phenomenon was inhibited by heating the muscle, suggesting that lipid hydrolysis by phospholipase occurred in silver carp muscle.     

Comparison of lipid composition ofCandida guilliermondii grown on glucose,ethanol and methanol as the sole carbon source

The carbon and energy source for aerobically grown cultures ofCandida guilliermondii profoundly influenced the neutral lipid content and the fatty acid composition of the individual lipid components. Methanol (0.80%, w/v) grown cells cultivated at 30 C in presence of 0.025% ammonium sulfate contained 12% total lipids, 67% of which was neutral lipids. Glucose (0.74%, w/v) or ethanol (0.53%, w/v) grown cells contained 21–22% total lipids, 80% of which was neutral lipids, under the same conditions. Methanol-grown cells contained a decreased 18∶1 acid (52–54% of total fatty acids) and an increased 18∶2 acid (23–25%), as compared with glucose- or ethanol-grown cells which contained 57–66% 18∶1 acid and 8–14% 18∶2 acid, in both neutral and polar lipid fractions. The relationship between methanol metabolism and desaturation of fatty acid in yeast was discussed.     

Polyunsaturated fatty acids and neutral lipids in developing larvae of the oyster,Crassostrea virginica

The fatty acid composition of oyster larvae at various stages, as well as of the algal diet, were determined by gas liquid chromatography (GC). Saturated fatty acids are the major fatty acid components in all larval stages and account for 34–62%, 30–35% and 35–81% of the neutral, polar and total lipids of algal-fed larvae respectively. Weight percentage of saturated fatty acid in “starved” larvae was consistently higher (63–81%) during the whole period. The total polyunsaturated fatty acids were higher in the polar lipids than in the neutral lipids. The concentration of the ω3 fatty acids also was comparatively higher in the polar lipids than in the neutral lipids. In the total and neutral lipid fractions, the weight percentage of polyunsaturated and ω3 fatty acids was higher in the eyed than in the pre-eyed (pediveliger) larvae. Eicosapentaenoic acid (20∶5ω3) and 22∶6ω3 were not detected in lipids of “starved” and young larvae. There was an accumulation of 20∶5ω3, 22∶6ω3, and total ω3 fatty acids in the older larvae. Lipid classes were separated by thin layer chromatography (TLC). There was no qualitative change in lipid composition during larval development, but a marked increased of triacylglycerol in larvae up to the stage of maturation in algae-fed larvae. Contribution number 1195 of the Virginia Institute of Marine Science, Gloucester Point, VA 23062     

Fatty acid composition of rat hearts as influenced by age and dietary fatty acids

Fatty acid composition of neutral and polar lipid fractions from rat hearts was determined in rats of different ages as their diet source changed. Piebald rats were weaned at 21 days and were fed standard lab chow. Lipids from rat hearts, mothers milk and lab chow were purified on a Sephadex G-25 fine column and separated into neutral and polar lipid fractions by silicic acid column chromatography. These lipid fractions were then hydrolyzed and methylated with BF₃ in methanol, prior to gas liquid chromatographic separation on a 1/8 in. × 10 ft aluminum column of 15% EGS on 80–100 mesh acid-washed Chromosorb W. Three major fatty acids in the neutral lipid fraction comprised 72% of total neutral lipid fatty acids from young hearts. At sexual maturity (at least 74 days old) C_18∶1 was the major fatty acid, followed by C_16∶0 and C_18∶0. The same three fatty acids comprised 83% of total polar lipid fatty acids, but C_18∶0 was the major fatty acid, followed by C_16∶0 and C_18∶1. The fatty acid composition of dietary lipids influenced the total neutral lipid fatty acid composition of the rat heart, but had little influence on the fatty acid composition of the polar lipid fraction. Presented in part at the AOCS Meeting, New Orleans, April 1970.     

Egg yolk lipids and maternal diet in the nutrition of turkey embryo

Turkey hens were fed diets containing no added fat nor diets supplemented with soybean oil or neatsfoot oil. The composition of neutral and polar lipid fatty acids present in the unincubated turkey egg yolk was compared with that of those present in the yolk sac of the developing turkey embryo at different stages of development. Comparisons were made of the fatty acid fractions in the entire embryo homogenates, except liver and heart, which were analyzed separately. Changes in the relative amounts of the fatty acids are reported as affected by age of the embryo and by dietary lipids. The fatty acids from both the neutral and polar lipids which were utilized to the greatest extent for embryonic development were palmitoleic, oleic, linoleic, and linolenic, regardless of the dietary supplements. Arachidonic, tetracosenoic, and docosahexaenoic acids also were metabolized by the embryo. Saturated fatty acids, used by the embryo as development progressed, were palmitic, stearic, and arachidic acids. Analyses of the liver fatty acids showed that the C16∶0 C16∶1, C18∶0, C18∶1, and C20∶4 acids in the neutral and polar lipids decreased with embryonic development and varied with the type of diet. The heart contained low levels of myristic, palmitic, stearic, arachidic, and arachidonic acids in the neutral lipids and palmitoleic and oleic acids in the polar lipids.     

Lipids of seven cereal grains

Grain samples of representative varieties of barley, corn, oats, rye, sorghum, triticale, and wheat grown commercially in the north central US were analyzed. Chemical constituents of the varieties studied are presented to provide an overview of their characteristics. Lipids of the milled grain samples were solvent extracted, classified by silicic acid column chromatography, and separated by thin layer chromatography. Fatty acid composition of the total lipid was determined by gas liquid chromatography and the fatty acid content was determined by saponification and extraction. Total lipid content of the grains ranged from 2.3% for ‘Polk’ wheat to 6.6% for ‘Chief’ oats. Lipid composition varied considerably. The row crops, corn and sorghum, have a high neutral lipid and low glycolipid content. The small grain varieties have a more balanced distribution among neutral lipids, glycolipids, and phospholipids. Fatty acid composition of the total lipid was similar for all grains. Minor qualitative differences were noted among the lipid classes of the 7 cereals.     

Fatty acid positional distribution in egg yolk triglycerides from various avain species

The fatty acid composition and distribution in egg yolk triglycerides and phosphatides from the turkey, duck, prairie chicken, bobwhite quail, Japanese quail, and inbred-hybrid and midget mutant hens were determined after all species had been fed diets of similar fat and fatty acid content for 90 days. Total volk lipids were composed of ca. two-thirds neutral lipids and one-third polar lipids. The predominant fatty acids were palmitic and stearic. There were statistically significant differences in the my ristic, palmitic, palmitoleic, linoleic, and linolenic acids in the yolk triglycerides and in the proportion of 16∶1, 18∶0, 18∶2, arachidonic, docosanoic, docosahexaenoic, and tetracosanoic acids in the phosphatides among the various species. Linoleic acid predominantly was linked at the 2-position in the yolk triglycerides followed by the 20∶4 acid. The 18∶1 acid also was found preferentially at the 2-position. There was a low level of 18∶2 in the yolk triglycerides and phosphatides from the duck and an especially high level of 20∶4 acid in the phosphatides. The triglycerides in the species studied have essentially the same distribution of fatty acids in the 2-position. In all the species, the affinity for the fatty acids at the 2-position is in the following order: 18∶2=20∶4>18∶1 =18∶3>18∶0=16∶1>14∶0>16∶0 Differences observed among the various genera did not appear to follow taxonomic boundaries. The duck has an efficient system for converting 18∶2 into 20∶4 by elongation and desaturation. The prairie chicken apparently has a high requirement for 18∶2 but an inadequate system for its conversion into 20∶4.     

Thermophilic fungi: II. Fatty acid composition of polar and neutral lipids of thermophilic and mesophilic fungi

The relative per cents of polar and neutral lipids and the fatty acid profile of the polar and neutral lipids of nine thermophilic and nine mesophilic fungi were examined and compared. The polar lipids of the thermophiles contained an average of 0.89 double bonds per mole fatty acid (unsaturation index, USI) and were considerably more saturated than the corresponding lipids of the mesophiles (average 1.32 USI). Within the thermophilic species the polar lipids were generally more saturated than the neutral lipids (average 0.95 USI) and in the mesophilic species the polar lipids were usually more saturated than the neutral lipids (average 1.14 USI). The mesophiles produced higher levels of 16∶1, 18∶2 and 18∶3 fatty acids than the thermophiles and preferentially incorporated 16∶1 and 16∶2 into their polar lipids. The thermophiles produce higher levels of saturated fatty acids and 18∶1 than the mesophiles and preferentially incorporated the saturated fatty acids into their polar lipids.     

Thermophilic fungi: IV. The lipid composition of six species

The lipid composition of six thermophilic fungi (Myriococcum albomyces, Mucor miehei, Papulaspora thermophila, Rhizopus sp.,Thielavia thermophila (+)Thielavia thermophila (−), andTorula thermophila) was examined. The relative per cent total lipids (4.9–26.3%), neutral lipids (55.5–88.3%), polar lipids (11.7–44.6%) and the fatty acid profile of each lipid fraction was determined. The predominant fatty acids were 16∶0, 18∶0 and 18∶2, and lesser amounts of 12∶0, 14∶0, 15∶0, 16∶1, 16∶2, 17∶0 and 18∶3 were present. The total lipids contained an average of 0.96 double bonds per mole fatty acid (unsaturation index [USI]) the neutral lipids 0.86 USI and the polar lipids 0.84 USI, excluding the values forTorula thermophila. These data show a high degree of saturation and are consistent with data reported for other fungal thermophiles.Torula thermophila possessed abnormally high USI values (1.15–1.50) and was cultured at three different temperatures (25, 45 and 51 C). As the culture temperature ofTorula thermophila increased, the USI decreased. The USI of the polar lipids ofTorula thermophila at 25, 45 and 51 C were 1.50, 1.28 and 1.11, respectively. Thus the membrane lipids of this fungus appear unusual for a thermophile.     

Fertility and testicular fatty acid composition in the chicken as influenced by vitamin E and ethoxyquin

The fatty acid composition of testicular lipids has been determined and related to fertility data from groups of dubbed White Leghorn cockerels after a 50-week feeding period on rations containing 10% safflower oil or coconut oil. Supplements of ethoxyquin ord-α-tocopherol acetate maintained fertility in birds raised on rations containing safflower oils. This response was associated with higher proportions of 22∶4 ω6 and lower proportions of 18∶2 ω6 in testicular lipids. Testes size was quite variable in the unsupplemented group with changes in fatty acid composition being more pronounced in the smaller testes. A multiple regression was calculated using data from those birds on the safflower oil ration. With a correlation ratio of 0.90 fertility was expressed as a function of testes size, semen concentration and the proportions of 18∶2 ω6, 20∶4 ω6 and 22∶4 ω6 in testicular lipids. Despite the low intake of linoleate significant levels of polyunsaturated fatty acids were maintained in testicular lipids of birds fed the coconut oil rations. The major changes in fatty acid composition of testicular lipids produced by this variable was a decrease in the proportion of 18∶2 ω6 and an increase in the proportion of 18∶1. Paper No. 3050, Oregon Agricultural Experiment Station.     

Characterization of porcine omental lipids

Porcine omental lipid extracts were fractionated and the major lipid components characterized. Approximately 97% of the chloroform/methanol extract consisted of triglycerides containing primarily 16∶0, 18∶0, 18∶1, and 18∶2 fatty acids. Small quantities of free fatty acids, cholesterol, di- and monoglycerides were also detected. The phospholipid fraction, obtained by solvent partition and Unisil column chromatography and characterized by high performance liquid chromatography (HPLC) and HPLC-mass spectrometry, was found to consist primarily of phosphatidylcholine, sphingomyelin, phosphatidylethanolamine, phosphatidylserine, and phosphatidylinositol. The neutral glycolipids, isolated by solvent partition and Unisil column chromatography and identified by HPTLC and HPLC, were found to consist primarily of di-, tri-and tetraosylceramides. The complex glycolipid fraction, obtained from Folch upper phase solvent partition and characterized by HPTLC and immunoblotting, was found to consist primarily of ganglio-, globo-, and neolacto- neutral glycolipids and ganglio-, globo-, neolacto- and fucosylated gangliosides.     

Occurrence of wax esters and 1-O-alkyl-2,3-diacylglycerols in goat epididymal sperm plasma membrane

Two unusual lipid classes were detected by thin-layer chromatography in the neutral lipids derived from goat cauda-epididymal sperm plasma membrane. The lipids were identified as wax esters and 1-O-alkyl-2,3-diacylglycerols based on chromatographic properties, identity of their hydrolysis products, and infrared/¹H nuclear magnetic resonance spectral evidence. The membrane containedca. 3 and 5 μg/mg protein of wax esters and alkyldiacylglycerols, respectively. The relative proportions of wax esters and alkyldiacylglycerols in the total neutral lipids were 1.5% and 2.4%, respectively. The lipids contained fatty acids with chain lengths of C₁₄ to C₂₂. The major fatty acids of the wax esters were 14∶0, 16∶0, 16∶1ω7, 18∶0 and 18∶1ω9. The fatty acids in alkyldiacylglycerol were 16∶0, 18∶0, 22∶5ω3 and 22∶6ω3. Alkyldiacylglycerol was particularly rich in docosahexaenoic acid 22∶6ω3) representing 30% of the total fatty acids. The alcohols of wax ester were all saturated with C₂₀–C₂₉ carbon chains. The deacylated products derived from alkyldiacylglycerols were identified as hexadecyl, octadecyl and octadec-9′-enyl glycerol ethers.     

Effects of cyclopropene fatty acids on the lipid composition of the Morris hepatoma 7288C

Fatty acids ofSterculia foetida were added to the medium used to maintain the Morris hepatoma 7288C in culture. The effect of this supplement on the lipid composition was examined. Overall, monoene levels were decreased with 18∶1 levels reduced by 40%. Saturated fatty acid levels were increased, with stearate (18∶0) levels 220% of control values. No effect occurred on the level of polyunsaturates (18∶2, 20∶4, 22∶5, 22∶6). These changes in fatty acid makeup were observed in both neutral and phospholipid fractions, and all lipid classes were affected. Triglycerides were most affected with a 66% decrease in 18∶1. There appeared to be little specificity of effect in the phospholipids with 18∶1 levels decreased 40–60% in all classes. All classes were therefore dependent on an endogenous supply of 18∶1. Examination of the distribution of geometrical isomers of 18∶1 reveals that in all lipid classes, except diphosphatidylglycerol (DPG), the ratio of Δ11 to Δ9 isomer decreased toward the isomeric distribution displayed by total medium lipids. In DPG, although 18∶1 levels were lowered, the isomeric distribution increased. DPG, synthesized and found in the mitochondria, may use a separate pool of 18∶1 during synthesis. Cyclopropene fatty acids (sterculic and malvalic) were incorporated into both neutral and phospholipid fractions with preferential incorporation into triglycerides. Cyclopropene fatty acids were not selectively incorporated into any phospholipid species. Sphingomyelin did not incorporate cyclopropene fatty acids, indicating that a different class of acyltransferase is used in the formation of this phospholipid class.     

Lipid and fatty acid characterization and metabolism in the sea anemonePhymactis clematis (Dana)

Neutral lipid, phospholipids and fatty acids of the sea anemonePhymactis clematis from the south-west Atlantic were characterized and quantified in spring and autumn. Neutral lipids predominated over phospholipids in both seasons. Triacylglycerol and diacylglycerol ethers were the major lipids. In spring, an increase of esterified sterols was noted. The major fatty acids found were 22∶5ω3, 20∶5ω3 and 16∶0. The sea anemones were also incubated in vivo with either [1-¹⁴C]linoleate or [1-¹⁴C] α-linolenate for 2 hr. Isotope incorporation into lipids and their transformations into higher fatty acids were examined. Both precursors were incorporated into the lipids, mainly in triacylglycerols and mono-acylglycerols, while α-linolenate was also incorporated into phospholipids. The radioactive linoleate was elongated to 20∶2, 22∶2 and 24∶2 fatty acids, but not desaturated to 18∶3ω6. α-Linolenate was desaturated by Δ6 desaturase to 18∶4ω3. The specificity of Δ6-desaturase is discussed.     

Lipids of some thermophilic fungi

Total lipid content in the thermophilic fungi—Thermoascus aurantiacus, Humicola lanuginosa, Malbranchea pulchella var.sulfurea, andAbsidia ramosa—varied from 5.3 to 19.1% of mycelial dry weight. The neutral and polar lipid fractions accounted for 56.4 to 80.2% and 19.8 to 43.6%, respectively. All the fungi contained monoglycerides, diglycerides, triglycerides, free fatty acids, and sterols in variable amounts. Sterol ester was detected only inA. ramosa. Phosphatide composition was: phosphatidyl choline (15.9–47%), phosphatidyl ethanolamine (23.4–67%), phosphatidyl serine (9.3–17.6%), and phosphatidyl inositol (1.9–11.9%). Diphosphatidyl glycerol occurred in considerable quantity only inH. lanuginosa andM. pulchella var.sulfurea. Phosphatidic acid, detected as a minor component only inM. pulchella var.sulfurea andA. ramosa, does not appear to be a characteristic phosphatide of thermophilic fungi as suggested earlier. The 16∶0, 16∶1, 18∶0, 18∶1, and 18∶2 acids were the main fatty acid components. In addition,A. ramosa contained 18∶3 acid. Total lipids contained an average of 0.93 double bonds per mole of fatty acids, and neutral lipids tend to be more unsaturated than phospholipids.     

The lipid components of white potato tubers (Solanum tuberosum)

Four Canadian varieties of potatoes were examined for their lipid composition. Lipids, extracted with chloroformmethanol, were shown by TLC and column chromatography to consist of 16.5% neutral lipids, 45.5% phospholipids and 38.1% glycolipids. Among the phospholipids and glycolipids, phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl inositol, the galactolipids and the sterol glucosides were the major lipids. The predominant fatty acids were palmitic (19.5%), linoleic (44.8%) and linolenic (30.4%, in Kennebec). Analyses of the fatty acids of stored potatoes showed a marked decrease in linoleic acid and an increase in linolenic acid, in the Irish Cobbler and Sebago potatoes. β-sitosterol comprised 85.0% of total sterols. Nearly half of the carotenoids was lutein (xanthophyll), the others being α-carotene, β-carotene, an unidentified pigment and lutein epoxide. Contribution No. 101 of the Food Research Institute, Canada Department of Agriculture.     

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.