Positional distribution of the fatty acids in the triglycerides of mango (Mangifera indica) kernel fat

Triglycerides of mango seed kernel fat contain, depending on the variety, 32.4–44.0% of stearic acid and 43.7–54.5% of oleic acid. Palmitic and linoleic acids represent, respectively, 5.9–9.1% and 3.6–6.7% of the fatty acids. The triglycerides also contain minor amounts of arachidic and linolenic acids. Palmitic, stearic and arachidic acids were almost exclusively distributed among thesn-1-andsn-3-positions. Oleic acid represented 85–89% of the fatty acids at thesn-2-position. Oleic acid at thesn-1- andsn-3-positions showed a preference for thesn-1-position. Linoleic acid was mainly esterified at thesn-2-position. The amounts of saturated fatty acids, i.e., palmitic and stearic acids, and of oleic acid, at thesn-1- and sn-3-positions, were linearly related to their respective contents in the total triglycerides.     

Fatty acid composition of seed oil triglycerides inCoincya (Brassicaceae)

Oil and triglyceride contents and fatty acid composition were determined for seeds in nine taxa belonging to the genusCoincya (Brassicaceae) on the Iberian Peninsula (Spain and Portugal). The oil content ranges from 11.1 to 24.6%, triglycerides from 68.7 to 88.5%. The major fatty acids were erucic (24.6–30.5%), linolenic (17.7–27.7%), linoleic (13.9–24.6%) and oleic acid (12.3–21.8%).     

Composition of total lipids in rapeseed

Total lipids in medium and low erucic acid cul-tivars of rapeseed(Brassica napus var. Sinus and Janpol, resp.) were fractionated into polar and non-polar constituents. Triglycerides, diglycerides, mono-glycerides, free fatty acids, sterol esters, sterols, phos-pholipids and glycolipids were quantitated and their fatty acid compositions determined. Triglycerides and phospholipids constituted 92 and 3.4%, resp., of the total lipid from each cultivar. Triglycerides were lower in saturated fatty acids but higher in monoun-saturated acids and linolenic acid than other lipid fractions. Phospholipids and glycolipids were higher in linoleic acid content than other lipid classes. Generally, the reduction in long chain, monoenoic, fatty acids was associated with a corresponding increase in oleic acid in most low erucic acid frac-tions.     

Fatty acid composition of erythrocyte,platelet, and serum lipids in strict vegans

The fatty acid composition of erythrocytes, platelets, and serum lipids was compared between subjects who had been eating a strict uncooked vegan diet (“living food”) for years and omnivore controls. The vegan diet contains equal amounts of fat but more monounsaturated and polyunsaturated and less saturated fatty acids than the mixed diet of the control group. In vegans, the proportion of linoleic acid was greater in all lipid fractions studied. Also, the levels of other n−6 fatty acids were greater, with the exception of arachidonic acid levels, which were similar in most fractions. In erythrocytes, platelets and serum phospholipid fractions, this increase was mainly at the expense of the n−3 fatty acids. The proportions of eicosapentaenoic and docosahexaenoic acid were only 29–36% and 49–52% of those in controls, respectively. In vegans the ratio of n−3 to n−6 fatty acids was only about half that in omnivores. In addition to the lower levels of n−3 fatty acids, the proportions of palmitic and stearic acids were lower in serum cholesteryl esters, triglycerides and free fatty acids of vegans. The proportion of oleic acid was slightly lower only in serum cholesteryl esters and erythrocyte phosphatidylserine. The results show that, in the long term, the vegan diet has little effect on the proportions of oleic and arachidonic acids, whereas the levels of n−3 fatty acids are depressed to very low levels with prolonged consumption of the high linoleic and oleic acid components of this diet.     

The effect of dietary erucic acid on cardiac triglycerides and free fatty acid levels in rats

Male Sprague-Dawley rats, 3 weeks of age, were fed semisynthetic diets containing test oils at 20% by weight for 3 days, 1 week, and 16 weeks. The test oils contained up to 22.3% erucic acid. Growth retardation was evident in rats fed rapeseed oil high in erucic acid, and soybean oil and Tower rapeseed oil diets containing about 5% erucic acid. Cardiac triglyceride accumulation was found in rats fed diets containing about 5% erucic acid but not in rats fed Tower rapeseed oil which contains 0.2% of this acid. The cardiac free fatty acid levels were low, 50–100 μg/g of wet heart tissue, and were not affected by feeding diets containing about 5% erucic acid. Feeding a diet containing a high erucic acid rapeseed oil did result in higher free fatty acid levels but only at 3 days and 1 week; the level at 16 weeks was similar to the other oils. The fatty acid analysis of cardiac triglycerides and free fatty acids showed high percentages of erucic acid at 3 days and 1 week; at 16 weeks these levels had declined significantly. The results indicate that the accumulated erucic and eicosenoic acids, at 3 days and 1 week, accounted for the increase in cardiac free fatty acids when rats were fed the high erucic acid rapeseed oil. There appears to be no evidence that the early cardiac triglyceride or free fatty acid accumulation is related to the formation of the long term myocardial lesions. Contribution No. 739 Animal Research Institute.     

Positional distribution of the fatty acids in the triglycerides of the oil of some african peanut varieties

The distribution of fatty acids between the sn-1-, sn-2- and sn-3-positions of the triglycerides from the oils of eight African peanut varieties has been determined. The saturated fatty acids and eicosenoic acid occur almost exclusively at the sn-1- and sn-3-positions. The sn-1-position contained slightly more palmitic acid than the sn-3-position. The fatty acids with a chain length exceeding 18 carbons were preferentially incorporated in the sn-3-position. Linoleic acid was preferentially esterified at the sn-2-position, whereas oleic acid was equally distributed among the three positions. The amount of the saturated fatty acids, i.e., palmitic and stearic acid, and of oleic acid and linoleic acid incorporated in the sn-1-, sn-2-and sn-3-position, were each linearly related to their respective content in the triglycerides.     

The effect of clofibrate on heart and plasma lipids in rats fed a diet containing rapeseed oil

The effect of clofibrate on heart and plasma lipids in rats fed a diet containing 30% of the calories as peanut oil (PO) or rapeseed oil (RSO) (42.7% erucic acid and 0.5% eicosenoic acid) was studied. A decrease of erucic acid content to one-third and concomitant increase in the content of 18∶1, 16∶1 and 16∶0 fatty acids in plasma triacylglycerols were observed after administration of clofibrate to rats fed the RSO-diet. It is suggested that these changes reflect the increased capacity of the liver to chainshorten very long chain length fatty acids. The extent of lipidosis in the heart of rats fed the RSO-diet was decreased by 50% by clofibrate. However, the concentration of erucic acid in heart triacylglycerols decreased much less (30%) than the concentration of all other fatty acids (50–65%). It is concluded that the clofibrate administration increased the oxidative capacity of the heart mitochondria and that the heart cell does not have an efficient system to handle very long chain length monounsaturated fatty acids as does the liver.     

Polar and nonpolar lipids and their fatty acid composition of a fewFusarium species

A few species ofFusarium have been evaluated for their potential to produce lipids. The isolates under investigation exhibited wide variation with respect to the mycelial weight, total lipid content and percentage composition of polar and nonpolar lipids in which triglycerides were the major components (81–90%). Palmitic, stearic, oleic and linoleic acids were the major fatty acids in both the fractions. The polar lipids contained higher levels of linoleic acid, whereas nonpolar lipids contained oleic acid as the predominant acid. Nonpolar lipids were more saturated than polar lipids.     

Determination of the fatty acid composition of the oil in intact-seed mustard by near-infrared reflectance spectroscopy

Near-infrared reflectance spectroscopy (NIRS) was used to estimate the fatty acid composition of the oil in intact-seed samples of Ethiopian mustard (Brassica carinata Braun) within a mutation breeding program that produced seeds with variable fatty acid compositions. Five populations, from 1992 to 1996 crops, were included in this study; and NIRS calibration equations for major fatty acids (palmitic, stearic, oleic, linoleic, linolenic, eicosenoic, and erucic) were developed within each single population. Furthermore, global calibration equations, including samples from the five populations, were developed. After external validation, the NIRS technique permitted us to obtain a reliable and accurate nondestructive estimation of the fatty acid composition of the oil, especially for the major acids—oleic, linoleic, linolenic, and erucic. For these, the r ² in external validation was higher than 0.95 by using both single-and multipopulation equations, and higher than 0.85 for the remaining fatty acids. Moreover, the multipopulation equations provided an accurate estimation of samples from a population not represented in the calibration data set, with values of coefficient of determination in validation (r ²) from 0.80 (palmitic and eicosenoic acids) to 0.97 (erucic acid). The ability of NIRS to discriminate among different fatty acid profiles was mainly due to changes within six spectral regions, 1140–1240, 1350–1400, 1650–1800, 1880–1920, 2140–2200, and 2240–2380 nm, all of them associated with fatty acid absorbers. Thus, NIRS can be used to estimate the fatty acid composition of Ethiopian mustard seeds with a high degree of accuracy, provided that calibration equations be developed from calibration sets that include large variability for the fatty acid composition of the oil.     

Effects of rapeseed oil on fatty acid oxidation and lipid levels in rat heart and liver

The comparative rates of oxidation of erucic and oleic acids and of their CoA esters were studied in heart and liver mitochondria of rats fed a standard diet or semisynthetic diets containing 25% of the calories as either rapeseed oil (46.6% erucic and 10.4% eicosenoic acid) or olive oil, for a period of 5 months. The long exposure to the diet containing 25% rapeseed oil did not alter the oxidative activity of mitochondria and did not induce morphological changes in the heart. It is confirmed that erucic acid is oxidized in mitochondria at lower rates than other long chain fatty acids and that its activation as CoA derivative may be one of the rate limiting steps of the overall oxidation process. Total lipids and triglycerides do not significantly change in the heart whereas they increase in the liver of rats fed the diet containing rapeseed oil.     

Solvent-free enzymatic glycerolysis of marine oils

Marine triglyceride oils (cod liver oil and oils from blubber of harp seal and minke whale) were reacted with glycerol using lipase as a catalyst at low temperature. A solvent-free batch system with magnetic stirring was used. Solidification of the reaction mixture occurred, and a mixture of mono-, di-, and triglycerides was obtained in all cases. The recovered glyceride mixtures were solid at room temperature. The yield of monoglyceride (MG) and the fatty acid profile of the MG fractions were dependent on oil and the type of lipase used as a catalyst. Of the commercially-available lipases investigated, lipase AK fromPseudomonas sp. synthesized the highest yield of MG (42–53%) at 5°C. These MG fractions were low in saturated fatty acids (4–11%) and high in long-chain monounsaturated fatty acids (52–69%). The concentration of n-3 polyunsaturated fatty acids was 12–20%.     

Distribution of individual fatty acids in the crystallization fractions of lard

Distribution of the individual fatty acids in the triglycerides of lard was determined by fractional crystallization, partial enzymatic hydrolysis with steapsin, and fatty acid analyses by GLC. It was found that none of the individual fatty acids corresponded to a random distribution in the crystallization fractions, but that the distribution of the total saturated and total unsaturated acids was very nearly random. The short chain fatty acids, C₁₄ and C₁₆, both saturated and unsaturated, were found to be more predominant in the 2-position than in the 1- and 3-positions of the lard triglycerides. All of the C₁₈ fatty acids were found to be more predominant in the 1- and 3-positions.     

Fatty acid spectrum of mediterranean wild cruciferae

Seed samples of 54 species of wild Cruciferae were newly collected from natural populations of the west Mediterranean and adjacent areas in a search for “new” oil crops. Oil contents and fatty acid compositions were determined simultaneously by gas liquid chromatography using methyl heptadecanoate as the internal standard. The study revealed large variations in oil content (6–48.8%), oleic acid (5–31.3%), linoleic acid (2–24.8%), linolenic acid (1.7–64.1%), and erucic acid (0–55.1%). Correlation coefficients between component fatty acids inter se and oil content were determined separately for all species, the tribe Brassiceae, and the genusBrassica. The promising species identified are being studied further.     

Comparative Evaluation of Physicochemical Properties of Jatropha Seed Oil from Malaysia,Indonesia and Thailand

The jatropha oil was extracted from the jatropha seeds collected from different origins viz., Malaysia, Indonesia and Thailand. The physicochemical properties such as density, viscosity, percentage free fatty acid (FFA), iodine value, saponification value and peroxide value of the extracted jatropha seed oil were evaluated. The evaluation of fatty acid composition using gas chromatography (GC) revealed that, oleic (42.4–48.8%) and linoleic acid (28.8–34.6%) are the dominant fatty acids present in the jatropha seed oil. The saturated fatty acids such as palmitic and stearic acid lie in the range 13.25–14.5 and 7–7.7%, respectively. The observed major triacylglycerol (TAG) composition was OOL (22.94–25.75%) and OLL (15.52–20.77%).     

Composition of seeds of cruciferous oil crops

Several species of the Cruciferae family are presently used as oilseed crops, viz.,Brassica campestris (turnip rape and sarson),B. juncea (brown or yellow mustard),B. napus (rape),Crambe abyssinica (crambe), andSinapis alba (white or yellow mustard). Seed oils of these species are characterized by variable but generally large amounts of erucic acid (22:1) in the triacylglycerols, which make up 95–98% of the total lipids of high quality, viable seeds. In addition to erucic acid, the major fatty acids are oleic (typically 10–25%), linoleic (10–20%), linolenic (7–11%) and eicosenoic (5–10%). However cultivars of rapeseed lacking erucic acid and having about 55–60% oleic, 20–25% linoleic and ca. 10% linolenic acid have been developed. The eicosenoic and erucic acids are located exclusively at the 1 and 3 positions of the triacylglycerol. As a consequence, major triacylglycerol types have carbon numbers 54, 56, 58, 60 and 62. The phospholipids of rapeseed are essentially devoid of erucic acid and have palmitic, oleic and linoleic acids as major fatty acids. Sterols generally amount to about 0.5% of the oil with β-sitosterol, campesterol and brassicasterol as major constituents (about 55%, 25% and 15%, respectively, of the total sterols). A few per cent of the total sterol fractions is cholesterol. The tocopherol content of rapeseed oil is about 800 ppm with α- and γ-tocopherol as major components. Cruciferous seeds contain a fairly large number of storage proteins. Thus approximately 50 components have been detected in alkaline extracts ofBrassica napus, a major portion of which are in the molecular weight range 120–150,000. The protein spectrum ofB. napus (rape) is more complex than that ofB. campestris (turnip rape) since the former species is an allotetraploid withB. oleracea (kale, cabbage, etc.) andB. campestris as parents. Approximately 5% of the fat free seed meal is composed of glucosinolates, which are split upon enzymatic hydrolysis to antinutritional factors: isothiocyanates, oxazolidinethiones and nitriles. The different crucifers discussed have both qualitative and quantitative differences with respect to glucosinolate content. One of nine papers presented at the Symposium, “Cruciferous Oilseeds,” ISF-AOCS World Congress, Chicago, September 1970.     

Human erythrocyte phosphoglycerides. II. Diet and lecithin structure

Lecithins (separated on basic silicic acid columns) were obtained from humans fed three different diets: eitherad-libitum or diets containing 40% of calories from linoleic acid (as corn oil) or from oleic acid (as triolein). Four lecithin subfractions were studied from each dietary group. Lecithin fractions eluting earliest (and apparently the least polar) contained the highest molar ratios of unsaturated fatty acids and the highest proportion of C-20 to C-22 polyunsaturated fatty acids. A slight increase in proportions of diunsaturated molecules occurred in corn oil and triolein groups. However, over 90% of lecithins of each dietary group were maintained as themonosaturated - monounsaturated type. Therefore, in contrast to human adipose tissue triglycerides, the saturated/unsaturated fatty acid ratio of lecithins of the erythrocyte membrane is largely unaffected by immense increases in dietary unsaturated fatty acid. Major shifts of oleic and linoleic acid occurred but proportions were unaltered of longer chain length (>C-18) polyunsaturated fatty acids. The relevance of these findings to membrane structure and function and to glycerophosphatide biosynthesis is discussed.     

Effect of diet on triglyceride structure and composition of egg yolk lipids

Hens were fed a practical diet supplemented and unsupplemented with 5% menhaden oil and a synthetic fat-free diet for a period of 90 days. Egg yolks from hens fed each of the three diets were analyzed for fatty acid composition and positional distribution of the fatty acids by successive chromatographic techniques. The triglycerides were resolved into fractions containing, 0, 1, 2 and 3+ double bonds per molecule. Each of these types was quantitated and analyzed for fatty acid distribution. The positional distribution was determined with the aid of pancreatic lipase hydrolysis. The feeding of the practical diet supplemented with 5% menhaden oil produced an increase in the 14∶0 acid in the intact triglycerides, 2-monoglycerides and 1,3-diglycerides with the majority of this acid being bound in the 1,3 positions. In the monounsaturated triglycerides the 16∶0 acid was linked predominantly at the 1,3 positions. The feeding of the fat-free diet produced a decrease in the 16∶1 acid content of the egg yolk lipids in the monounsaturated series, in the intact triglycerides, the 2-monoglycerides and the 1,3-diglycerides. The 18∶0 acid was linked more often at the 1,3 positions than at the 2 position, and was not affected by the diet consumed by the hens. Hens fed the fat-free diet produced more monounsaturated and diunsaturated triglycerides than those fed the other diets. Linoleic acid exhibited the greatest degree of preference for the 2 position, which was followed in turn by oleic acid. All other major acyl components were found to be preferentially esterified at the 1,3 positions. The difference observed in the fatty acid composition of egg yolk neutral and polar lipids was attributable to the fatty acid content of the diet. In the case of the oleic and linoleic acids, there was less variation in the saturated fatty acid content, which could be traced to the type of diet fed.     

Composition of the neutral and phospholipid fractions from ginkgo nuts (Ginkgo biloba) and fatty acid composition of individual lipid classes

The purified lipid fraction (1.26% on the wet weight basis) from the nuts ofGinkgo biloba was found to be 90.6% neutral lipids, 7.5% polar lipids, and a very small amount of glycolipids. Main fatty acids in the triglyceride fraction were oleic and linoleic acids, and those in the phospholipid fraction were palmitic acid in addition to these unsaturated acids. The enzymic hydrolysis of the triglyceride and individual phospholipid fractions showed that only the triglyceride and phosphatidylcholine fractions contained relatively large amounts of unsaturated acids in their β-positions. The gas liquid chromatography-mass spectrometric analysis of the fatty acids of the steroid ester fraction indicated the presence of lignoceric, cerotic, montanic, and melissic acids as well as a lactone and compounds suspected to be phenolic acids containing long chain diols.     

Variation in fatty acid composition of the different acyl lipids 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 and Thonn. andS. angustifolium (Oliv.) Engl.] were studied for their oil content and fatty acid composition of the total lipids. The wild seeds contained less oil (ca. 30%) than the cultivated seeds (ca. 50%). Lipids from all four species were comparable in their total fatty acid composition, with palmitic (8.2–12.7%), stearic (5.6–9.1%), oleic (33.4–46.9%) and linoleic acid (33.2–48.4%) as the major acids. The total lipids from selected samples were fractionated by thin-layer chromatography into five fractions: triacylglycerols (TAG; 80.3–88.9%), diacylglycerols (DAG; 6.5–10.4%), free fatty acids (FFA; 1.2–5.1%), polar lipids (PL; 2.3–3.5%) and steryl esters (SE; 0.3–0.6%). Compared to the TAG, the four other fractions (viz, DAG, FFA, PL and SE) were generally characterized by higher percentages of saturated acids, notably palmitic and stearic acids, and lower percentages of linoleic and oleic acids in all species. Slightly higher percentages of long-chain fatty acids (20∶0, 20∶1, 22∶0 and 24∶0) were observed for lipid classes other than TAG in all four species. Based on the fatty acid composition of the total lipids and of the different acyl lipid classes, it seems thatS. radiatum andS. angustifolium are more related to each other than they are to the other two species.     

Changes in rat heart phospholipid composition after rapeseed oil feeding

The influence of long duration rapeseed oil feeding with high or low levels of erucic acid has been investigated on rat heart phospholipids. The rats treated for 20 wk with rapeseed oil containing 46.2% erucic acid showed a twofold increase in the sphingomyelin content of the heart. Treatment with primor rapeseed oil (3.7% erucic acid) for 20 wk did not modify phospholipid composition of rat heart. The fatty acid patterns of phosphatidylethanolamine and phosphatidylcholine were slightly influenced by the high erucic rapeseed oil; eicosenoic acid was incorporated preferentially into position one, but erucic acid showed a random distribution in both. After high erucic rapeseed oil feeding, 22∶1 was incorporated into cardiolipin (5.6%) and sphingomyelin (10.5%). The incorporation of 22∶1 into sphingomyelin was associated with an increase of the percentage of 24∶1 (14.6%) and a decrease of saturated long chain fatty acid (22∶0, 24∶0) percentages. Primor rapeseed oil caused a slight increase of 24∶1 and a decrease of 22∶0 and 24∶0 in rat heart sphingomyelin. As cardiolipin is localized in the inner membrane of mitochondria and sphingomyelin in plasma and microsomal membranes, the acyl-moiety alterations of both phospholipids might be correlated to the pathological lesions of rat heart after a long duration of rapeseed oil feeding.