Fatty Acid Profile of Sunshine Bass: II. Profile Change Differs Among Fillet Lipid Classes

Fatty acid (FA) profile of fish tissue mirrors dietary FA profile and changes in a time-dependent manner following a change in dietary FA composition. To determine whether FA profile change varies among lipid classes, we evaluated the FA composition of fillet cholesteryl esters (CE), phospholipids (PL), and triacylglycerols (TAG) of sunshine bass (SB, Morone chrysops x M. saxatilis) raised on feeds containing fish oil or 50:50 blend of fish oil and coconut, grapeseed, linseed, or poultry oil, with or without implementation of a finishing period (100% FO feed) prior to harvest. Each lipid class was associated with a generalized FA signature, irrespective of nutritional history: fillet PL was comprised largely of saturated FA (SFA), long-chain polyunsaturated FA (LC-PUFA), and total n-3 FA; fillet TAG was higher in MC-PUFA and total n-6 FA; and fillet CE was highest in monounsaturated FA (MUFA). Neutral lipids reflected dietary composition in a near-direct fashion; conversely, PL showed evidence of selectivity for MC- and LC-PUFA. Shorter-chain SFA were not strongly reflected within any lipid fraction, even when dietary availability was high, suggesting catabolism of these FA. FA metabolism in SB is apparently characterized by a division between saturated and unsaturated FA, whereby LC-PUFA are preferentially incorporated into tissues and SFA are preferentially oxidized for energy production. We demonstrated provision of SFA in grow-out feeds for SB, instead MC-PUFA which compete for tissue deposition, meets energy demands and allows for maximum inclusion of LC-PUFA within fillet lipids.     

Biomarkers for intake of dairy fat and dairy products

The aim of this study was to correlate the fatty acids characteristic of dairy fat (14:0, 14:1, 15:0, 17:0 and 17:1) in adipose tissue, serum lipid fractions and the estimated intake of dairy fat, and to investigate whether they can be used as biomarkers for dairy fat/product intake. The highest correlations were observed between 14:0 in adipose tissue and the estimated intakes of 14:0 (r = 0.60) and dairy fat (r = 0.50), and between 15:0 in adipose tissue and the estimated intakes of 15:0 (r = 0.55) and dairy fat (r = 0.55). Among the fatty acids in serum lipid fractions, 15:0 in cholesteryl esters (CE) and triacylglycerols showed the highest correlation to both 15:0 in adipose tissue, intakes of 15:0, dairy fat and dairy products. The results from our study suggest that the contents of fatty acids characteristic of dairy fat (14:0, 14:1, 15:0, 17:0, 17:1) in adipose tissue might be used as markers not only for the intake of dairy fat, but also of dairy products (times/day). When adipose tissue specimens are not available, 15:0 in serum CE appears to be the best marker for dairy fat intake. It was also observed that fatty acids from dairy fat are incorporated differently into serum lipid fractions and adipose tissue.     

Unusual Fatty Acid Isomers of Triacylglycerols and Polar Lipids in Female Limpet Gonads of <Emphasis Type="Italic">Cellana grata</Emphasis>

To investigate the occurrence of positional isomers of unsaturated fatty acids (FA) in triacylglycerols (TAG) and polar lipids (PL) in the female gonads of a dominant limpet, Cellana grata, fatty acid methyl esters (FAME) were fractionated according to the degree of their unsaturation by argentation thin-layer chromatography. Their structures were elucidated by gas chromatography-mass spectrometry of a combination of their FAME and picolinyl esters. A total of 125 different FA ranging from 12 to 24 carbon atoms were identified, and 105 unsaturated FA, including 34 nonmethylene-interrupted FA as minor components, were recognized. Although the major FA 16:0 and 18:1n-7, which accounted for more than 20 and 10%, respectively, of total FA, were present in TAG and PL, higher amounts of 20:4n-6 and 20:5n-3 were present in PL. Unsaturated FA consisting of more than five different positional isomers were 17:1, 19:1, 18:2, 19:2, 20:2, 21:2, 22:2, 20:3, and 22:3, most of which were present in TAG. Furthermore, a larger variety of nonmethylene-interrupted FA was found in TAG than in PL. This limpet gonad had a diverse assortment of unsaturated FA that comprised a wide range of unusual positional isomers with one to five double bonds.     

Determination of <Emphasis Type="Italic">c</Emphasis>9,<Emphasis Type="Italic">t</Emphasis>11-CLA in major human plasma lipid classes using a combination of methylating methodologies

Isomeric CLA exhibit several significant biological activities in animals and humans and are easily isomerized to their corresponding t,t-CLA isomers during methylation with various acid-catalyzed reagents. To minimize such isomerization and provide a valid quantification of human plasma CLA content, several methylation methods were tested. Plasma neutral lipid, nonesterified FA (NEFA), and polar lipid classes were separated into the following fractions: (i) cholesteryl ester (CE, 1.2 mg/12 mL, 37.5% lipids), (ii) TAG (0.8 mg/12 mL, 25% lipids), (iii) NFFA (0.2 mg/12 mL, 6.2% lipids), (iv) MAG/DAG/cholesterol (0.3 mg/12 mL, 9.4% lipids), and (v) phospholipid (PL, 0.5 mg/20 mL, 15.6% lipids). Data showed that c9,t11-CLA found in TAG, MAG/DAG/cholesterol, and PL fractions were converted to methyl esters with sodium methoxide within 2 h at 55°C. However, the c9,t11-CLA in the CE fraction could not be completely converted to methyl esters by sodium methoxide/acetylchloride in methanol or methanolic KOH; instead, CE was treated with sodium methoxide and methyl acetate in diethyl ether for 1 h. NEFA were converted to methyl esters with trimethylsilyldiazomethane (TMSDAM). All reaction mixtures were monitored by TLC prior to GLC analysis. The highest enrichment of c9,t11-18∶2 (% FA) was in TAG (0.31%), followed by CE (0.14%) and PL (0.13%). The above methylation methods were then applied to a small subset (n=10) of nonfasting plasma lipid fractions to confirm the applicability of these data. Results from this subset of samples also indicated that the greatest enrichment of c9,t11-CLA was present in the TAG fraction (0.39%), followed by CE (0.27%) and PL (0.22%). These data indicate that different plasma fractions have different c9,t11-CLA contents.     

Effects of margarine and butter consumption on distribution of trans-18∶1 fatty acid isomers and conjugated linoleic acid in major serum lipid classes in lactating women

Trans FA (TFA) have at least one trans double bond and comprise several isomers and types, including many of the CLA (e.g., c9, t11–18∶2 CLA). Some TFA may have adverse effects (e.g., cardiovascular disease), whereas some are though to have beneficial effects (e.g., anticarcinogenicity). The presence of TFA in human tissues and fluids is related to dietary intake, although this relationship is not completely understood—especially in regard to serum lipid fractions. This study was conducted as part of an investigation designed to test the influence of butter (B), “low TFA” margarine (LT), and regular margarine (RM) on milk fat content. Here we tested the secondary hypothesis that consumption of B, LT, and RM by lactating women would result in differential distribution of TFA and CLA in major serum lipid classes. Breastfeeding women (n=11) participated in this randomized Latinsquare study consisting of five periods: intervention I (5 d), washout I (7 d), intervention II (5 d), washout II (7 d), and intervention III (5 d). Extracted serum lipid was separated into cholesterol ester (CE), TAG, and phospholipid (PL) fractions and analyzed for total and isomeric TFA and CLA concentrations. Data indicate that TAG consistently contained the highest concentration of total t-18∶1. No interaction between treatment and fraction was found for any of the t-18∶1 isomers identified. Absolute concentration of each t-18∶1 isomer was greatest during the RM period, regardless of fraction. On a relative basis, concentrations of t10–18∶1 and t12–18∶1 were most responsive to treatment in the CE fraction. The concentration of c9, t11–18∶2 CLA was highest in the TAG fraction and lowest in the PL fraction, regardless of treatment. In summary, these results indicate (i) that there is a differential distribution of some isomeric TFA and CLA among human serum lipid fractions and (ii) that dietary TFA intake influences absolute and relative concentrations of some of the isomers in selected fractions.     

Mammary Uptake of Fatty Acids Supplied by Intravenous Triacylglycerol Infusion to Lactating Dairy Cows

Supplementing dairy cows with n-3 fatty acid-rich feeds does not easily increase quantities in milk fat. Previous results demonstrated very long-chain n-3 fatty acids are primarily transported in the PL fraction of blood, making them largely unavailable to the mammary gland for enrichment of milk fat. Our objective was to compare mammary uptake of fatty acids of increasing chain length and unsaturation delivered intravenously as TAG emulsions. Late lactation dairy cows were assigned to a completely randomized block design. Treatments were intravenous TAG emulsions enriched with oleic acid (OLA), linoleic acid (LNA), alpha-linolenic acid (ALA), or docosahexaenoic acid (DHA) and were delivered continuously at 16 mL/h for 72 h. Each treatment supplied 30 g/day of the target fatty acid. Treatment did not affect feed intake, milk yield, or milk composition, but all treatments reduced intake and yield. The proportion of DHA increased in plasma FFA, TAG, and PL with infusion. Increases of n-3 fatty acids, ALA, EPA, and DHA, were evident in the plasma PL fraction, suggesting re-esterification in the liver. Transfer efficiencies were 37.8 ± 4.1, 27.6 ± 5.4, and 10.9 ± 4.1 %, and day 3 total milk fatty acyl yields were 37.0 ± 3.4, 10.8 ± 0.4, and 3.3 ± 0.3 g for LNA, ALA, and DHA. Variation in oleic acyl yield prevented calculation of OLA transfer efficiency. Mammary uptake of fatty acids was reduced with increased chain length and unsaturation. Both liver and mammary mechanisms may regulate transfer of long-chain polyunsaturates.     

Hyperphagia modifies FA profiles of plasma phospholipids,plasma FFA,and adipose tissue TAG

Hyperphagia was achieved by continuous intracerebroventricular infusion of a melanocortin receptor antagonist (HS024; Neosystem, Strasbourg, France) in rats. The effects of hyperphagia on FA composition and concentration of plasma phospholipids (PL), plasma FFA, and adipose tissue TAG were studied in rats for 8 d [short-term hyperphagia (STH); n=8], or 28 d [longterm hyperphagia (LTH); n=9]. The control rats were treated with artificial cerebrospinal fluid for 8 d (n=8) or 28 d (n=10). The rats were fed the same regular diet. In STH rats the plasma PL and fasting plasma FFA contained higher concentrations of saturated FA (SFA) and monounsaturated FA (MUFA), and plasma FFA contained lower n−6 PUFA than in the control rats. In LTH rats the plasma PL contained higher concentrations of SFA, MUFA, and n−3 PUFA and higher proportions of 16∶1n−7 and 18∶1n−9 at the expense of 18∶2n−6 than in the control rats. In LTH rats the abundant dietary intake of 18∶2n−6 did not enrich 18∶2n−6 of the plasma PL or adipose tissue TAG. In LTH rats the fasting plasma FFA contained more than twofold higher concentrations of SFA and MUFA, and higher proportions of 16∶1n−7 and 18∶1n−9 at the expense of 18∶2n−6 than in the control rats. This animal obesity model shows that LTH affects the FA composition and concentration of plasma PL, plasma FFA, and adipose tissue TAG, a result consistent with changes associated with increased risk of various diseases in humans. These results also demonstrate that LTH alters the FA composition of plasma PL and adipose tissue TAG in a way that does not reflect the FA composition of dietary fat.     

Lipid Classes and Fatty Acid Composition of the Tropical Nudibranch Mollusks <Emphasis Type="Italic">Chromodoris</Emphasis> sp. and <Emphasis Type="Italic">Phyllidia coelestis</Emphasis>

Two nudibranch mollusks, Chromodoris sp. and Phyllidia coelestis, collected from tropical waters of the Northwestern Pacific, were analyzed for lipids. The aim of this study was to fill the gap in knowledge of lipid biochemistry of mollusks. Phospholipids (PL) were the dominating lipid class followed by sterols (13%). Neutral lipids were not detected in Chromodoris sp. By contrast, P. coelestis contained TAG, diacylglyceryl ether, long chain alcohol and esters of sterols. Among PL, PC was predominant (about 50%); PE, PS and CAEP were almost in equal proportions. Sixty five FA were identified as methyl esters and N-acyl pyrrolidides by GC-MS. The sea slugs exhibited a wide diversity of FA. The common marine n-3 PUFA, 20:5n-6 and 22:6n-3, constituted 0.6-1.3% of the total FA, whereas n-6 PUFA, 22:4n-6, 20:4n-6, and 18:2n-6, were the main (25%). Among monounsaturated FA, 7-21:1 was the main (up to 6.2%). The non-methylene-interrupted (NMI) FA were found (9.4 and 12.4%), including the known 5,11-20:2, 5,13-20:2, 7,13-22:2, 7,15-22:2 and a novel isomer 7,13-21:2 (up to 3.9%). The pathway of its biosynthesis was suggested. A series of very long chain FA (VLC FA), with the main 5,9-25:2 and 5,9-26:2, were identified. High level of VLC FA (8.7 and 11.7%) in sea slugs is apparently the result of predation on sponges. Another unique feature concerned a high abundance of various odd and branched FA (16.7 and 34%), which could have originated from the dietary origin or symbiotic bacteria. This is the first report on lipid and FA composition of nudibranchs.     

Incorporation of Arachidonic and Stearic Acids Bound to L-FABP into Nuclear and Endonuclear Lipids from Rat Liver Cells

The incorporation of exogenous fatty acids bound to L-FABP into nuclei was studied. Rat liver cell nuclei and nuclear matrices (membrane depleted nuclei) were incubated in vitro with [1-(14)C]18:0 and 20:4n-6 either free or bound to L-FABP, ATP and CoA. FA esterification in whole nuclei and endonuclear lipids was ATP-CoA-dependent, and with specificity regarding fatty acid type and lipid class. 18:0 and 20:4n-6, free or L-FABP bound, showed the same incorporation and esterification pattern in lipids of whole nuclei. Only 20:4n-6 L-FABP bound was less incorporated into TAG with respect to free 20:4n-6. In the nuclear matrix, 18:0 free or L-FABP bound was esterified with a higher specific activity (SA) into: PtdEtn > PtdIns, PtdSer > PtdCho. 20:4n-6 free or L-FABP bound was esterified into: PtdIns > PtdEtn > PtdCho. 20:4n-6:L-FABP was esterified in endonuclear total-PL and PtdIns with a greater SA with respect to free 20:4n-6 and with a minor one as FFA. To summarize, trafficking of FA to nuclei includes esterification of 18:0 and 20:4n-6 either free or L-FABP-bound, into nuclear and endonuclear lipids by an ATP-CoA-dependent pathway. Endonuclear fatty acid esterification was more active than that in whole nuclei, and independent of the nuclear membrane. Esterification patterns of fatty acids L-FABP-bound or free into whole nuclear lipids were the same whereas in the nuclear matrix, L-FABP could play an important role in the mobilization of 20:4n-6 into specific sites of utilization such as the PtdIns pools.     

Seasonal Variations of Lipid Content and Composition in <Emphasis Type="Italic">Perna viridis</Emphasis>

The total lipid content, composition of main lipid classes, composition of sterols and composition of fatty acids in the main glycerolipids of Perna viridis were analyzed through four seasons using TLC-FID and GLC. Mussel samples were collected during different seasons between 2003 and 2004 from Shengsi Island, Zhejiang Province, China and stored frozen prior to freeze-drying and lipid extraction. Ten grams of dried mussel powder of each season were analyzed. Total lipid content ranged from 14.5 g/100 g in spring month to 7.8 g/100 g dried mussel powder in autumn month. The predominant lipid in spring month was triacylglycerol (TAG), however, in the other three seasons the phospholipids (PL) was the main lipid class. The most abundant fatty acid in TAG, PL and phosphatidylcholine (PC) was 16:0, with the summer samples having the highest proportion (24-30% of total fatty acid) and winter the lowest (14-22%). In phosphatidylethanolamine (PE), the spring samples had the highest proportions of 16:0. The predominant polyunsaturated fatty acids (PUFA) were 22:6n-3 and 20:5n-3 in TAG, PL, PE and PC (25-40%). The proportions of 22:6n-3 and 20:5n-3 were higher in spring than in other seasons in PL and PE. There were nine sterols identified, with cholesterol being the predominant sterol, and other main ones were desmostersol/brassicasterol and 24-methylenecholesterol. Proportions of other fatty acids in different lipid fractions and the sterol compositions as well also varied seasonally. There were subject to the seasonal variations. Differences in lipid content and composition, fatty acid composition in different lipid fractions may be caused by multiple factors such as lifecycle, sex, variation of plankton in different seasons and temperature, which could influence physiological activities and metabolism.     

Daily Intake of Cod or Salmon for 2?Weeks Decreases the 18:1n-9/18:0 Ratio and Serum Triacylglycerols in Healthy Subjects

Intake of fish and omega-3 (n-3) fatty acids is associated with a reduced concentration of plasma triacylglycerols (TAG) but the mechanisms are not fully clarified. Stearoyl-CoA desaturase-1 (SCD1) activity, governing TAG synthesis, is affected by n-3 fatty acids. Peripheral blood mononuclear cells (PBMC) display expression of genes involved in lipid metabolism. The aim of the present study was to estimate whether intake of lean and fatty fish would influence n-3 fatty acids composition in plasma phospholipids (PL), serum TAG, 18:1n-9/18:0 ratio in plasma PL, as well as PBMC gene expression of SCD1 and fatty acid synthase (FAS). Healthy males and females (n = 30), aged 20–40, consumed either 150 g of cod, salmon, or potato (control) daily for 15 days. During intervention docosahexaenoic acid (DHA, 22:6n-3) increased in the cod group (P < 0.05), while TAG concentration decreased (P < 0.05). In the salmon group both eicosapentaenoic acid (EPA, 20:5n-3) and DHA increased (P < 0.05) whereas TAG concentration and the 18:1n-9/18:0 ratio decreased (P < 0.05). Reduction of the 18:1n-9/18:0 ratio was associated with a corresponding lowering of TAG (P < 0.05) and an increase in EPA and DHA (P < 0.05). The mRNA levels of SCD1 and FAS in PBMC were not significantly altered after intake of cod or salmon when compared with the control group. In conclusion, both lean and fatty fish may lower TAG, possibly by reducing the 18:1n-9/18:0 ratio related to allosteric inhibition of SCD1 activity, rather than by influencing the synthesis of enzyme protein.     

Short-term biological reproducibility of serum fatty acid composition in children

To assess the biological day-to-day reproducibility of the fatty acid composition in serum lipid fractions in children on their habitual diets, fasting serum specimens were collected from healthy 8- to 9-year-old boys at 2-day (n=21) or 7-day (n=19) intervals. Percentage compositions of fatty acids in serum cholesteryl esters (CE), triglycerides (TG), free fatty acids (FFA) and phospholipids (PL) were analyzed by gas chromatography. The reproducibility was estimated by calculating linear correlation coefficients between the values obtained at the two time-points. Generally the correlations were higher in CE and PL than in TG and FFA. In CE the 7-day correlations of major fatty acids were only slightly lower than the 2-day ones. In PL the impairment of correlations was somewhat greater than in CE, but in TG and FFA there was a marked drop in reproducibility from 2- to 7-day intervals. The 2-day correlation coefficients of the percentages of linoleate, dihomo-γ-linolenate, arachidonate and eicosapentaenoate in CE were 0.95, 0.84, 0.91 and 0.92, respectively. In PL, the respective values were 0.86, 0.82, 0.95 and 0.90. The persent results indicate high short-term biological reproducibility of fatty acid composition in serum CE and PL and clearly lower in those of TG and FFA.     

Marine lipid-based liposomes increase <Emphasis Type="Italic">in vivo</Emphasis> FA bioavailability

Liposomes made from an extract of natural marine lipids and containing a high n-3 PUFA lipid ratio were envisaged as oral route vectors for FA supplements in order to increase PUFA bioavailability. The absorption of FA in thoracic lymph duct-cannulated rats, after intragastric feeding of dietary fats in the form of liposomes or fish oil, was compared. Lipid and FA analyses were also performed on feces. Five mole percent α-tocopherol was added to fish oil and incorporated into the liposome membrane. The influence of α-tocopherol on FA lymph recovery was also investigated. In vivo, FA absorption in rats was favored by liposomes (98±1%) compared to fish oil (73±6%). In the same way, the DHA proportion in lymph was higher after liposome ingestion (78%) than after fish oil ingestion (47%). However, phospholipid (PL) concentration in lymph was not affected by the kind of dietary fat ingested, suggesting a PL regulation due to de novo TAG synthesis. The influence of the intramolecular distribution of n-3 PUFA in dietary lipids (TAG and PL) on the intramolecular FA distribution in TAG of chylomicrons was also investigated. The results obtained showed that the distribution of n-3 PUFA esterified on the sn-2 of chylomicron TAG depended on the lipid source administered. All these results correlated, at least partly, with in vitro liposome behavior under conditions that mimic those of the gastrointestinal tract. As a whole, this study pointed out that marine PL may constitute an attractive material for the development of liposomes as oral PUFA supplements.     

Lipid profile and fatty acid composition of two silurid fish eggs

The lipid content and the composition pattern of the lipid class including fatty acid composition in the eggs of two different Indian silurid cat fishes Ompok pabda and Wallagu attu have been examined. The lipid content of O. pabda and W. attu (on dry basis) are about 14.7% and 17.8% respectively. The major lipid classes are phospolipid (PL) and triacylglycerol (TAG). The O. pabda egg lipid contains more PL while the W. attu egg lipid contains more TAG. Phosphatidylcholine (PC) constitutes the major phospholipid followed by phosphatidylinositol (PI). PI represents in about 31.7% and 21.3% of total PC in O. pabda and W. attu respectively while phosphatidylethanolamine (PE) (about 28.0%) is significantly higher in the egg of W. attu than O. pabda (9.6%). Cholesterol content in egg of O. pabda is also higher (about 9.6%) than W. attu (4.1%). The lipids are rich in polyunsaturated fatty acids (PUFAs) and they are mainly concentrated in the respective PL fractions. Among PUFAs the arachidonic acid (20:4 n-6 AA) is present at about 9.3% in both egg PL. Eicosapentaenoic acid (20:5 n-3 EPA) is significantly lower in egg lipids of both W. attu (1.8%) and O. pabda (3.2%), whereas docosahexaenoic acid (22:6 n-3 DHA) is predominantly higher (14.6% and 18.1% in W. attu and O. pabda respectively) in their PL fractions.     

Dietary Lipid Intake only Partially Influences Variance in Serum Phospholipid Fatty Acid Composition in Adolescents: Impact of Other Dietary Factors

The present study aimed to assess the correlation between food and fatty acid (FA) intake and the serum phospholipid (PL) FA status in European adolescents and explored the percentage of variation in serum PL FA that could be attributed to dietary habits. Participants included 528 adolescents recruited in the HELENA Study. Dietary intake was assessed by two, self-administered, non-consecutive 24-h recalls. PL FA concentrations were measured in fasting venous serum samples. Reduced rank regressions were applied to examine the combined effect of food intakes. Results indicated that the variance in serum PL FA in adolescents, that could be explained by diet varied from 7.0 % for MUFA to 14.2 % for n-3FA. The variance in the long-chain n-3FA was mainly explained by fish intake but also by coffee and tea consumption. In conclusion this study indicated that dietary intake influences the serum PL FA status to a limited amount but that also other factors interfere. However, dietary intake is important as it is among those factors that could be modified. Furthermore, the results suggest that the overall dietary habits should be considered instead of only the consumption of single foods or nutrients, as the medium of the food or concomitant intake of foods and nutrients might interact and as such influence absorption or metabolism.     

Hypolipidemic Effects of Phospholipids (PL) Containing n-3 Polyunsaturated Fatty Acids (PUFA) Are Not Dependent on Esterification of n-3 PUFA to PL

Phospholipids (PL) containing n‐3 polyunsaturated fatty acids (PUFA) have beneficial effects of maintaining and promoting health compared with triacylglycerols (TAG) containing n‐3 PUFA or general PL. This study evaluated the effects of dietary PL containing n‐3 PUFA and elucidated the effects of the glycerophosphate structure and n‐3 PUFA on fatty acid (FA) metabolism in rats. Rats were fed a basal diet containing soybean oil alone, TAG containing n‐3 PUFA (1.8 %), soybean PL (2.7 %), PL containing n‐3 PUFA (2.7 %), or TAG containing n‐3 PUFA (1.8 %) + soybean PL (2.7 %). The present n‐3 PUFA‐supplemented diets had similar FA compositions, and the PL diets had similar PL compositions. TAG containing n‐3 PUFA reduced serum TAG contents, but did not affect serum cholesterol contents compared with soybean oil alone. PL diets containing n‐3 PUFA and the combination of TAG containing n‐3 PUFA and soybean PL resulted in decreased serum and liver TAG contents compared with the diet containing soybean oil alone, reflecting enhanced liver FA β‐oxidation. The results of this study show that TAG containing n‐3 PUFA with added soybean PL affects serum and liver TAG and cholesterol contents to a similar degree as PL containing n‐3 PUFA. TAG containing n‐3 PUFA and soybean PL are widely used as functional food ingredients and pharmaceutical constituents and are inexpensive compared with PL containing n‐3 PUFA. Therefore, the combination of TAG containing n‐3 PUFA and soybean PL has potential as a useful and inexpensive component of functional foods.     

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.     

Divergent incorporation of dietary trans fatty acids in different serum lipid fractions

Trans fatty acids may be involved in atherosclerotic vascular diseases. We investigated the incorporation of dietary trans fatty acids and oleic acid into the serum triglycerides (TG), cholesterol esters (CE), and phospholipids (PL). Fourteen healthy female volunteers, aged 23.2±3.1 yr (mean±SD), body mass index 20.8±2.1 kg/m² participated in this study. All subjects consumed both a trans fatty acid-enriched diet (TRANS diet) and an oleic acid-enriched diet (OLEIC diet) for 4 wk according to a randomized crossover design. Both experimental diet periods were preceded by consumption of a baseline diet for 2 wk which supplied 37% of total energy (E%) as fat: 18 E% from saturated fatty acids (SFA), 12 E% from monounsaturated fatty acids, and 6 E% from polyunsaturated fatty acids. Five E% of the SFA in the baseline diet was replaced by trans fatty acids (18∶1 t and 18∶2 c,t+18∶2t,t, where c is cis and t is trans) in the TRANS diet and by oleic acid (18∶1n-9) in the OLEIC diet. After the TRANS diet, the proportions of 18∶1t and 18∶2t increased (P <0.001) in all serum lipid fractions analyzed. The increase of 18∶1 t in TG and PL (1.80±0.28 vs. 5.26±1.40; 1.07±0.34 vs. 3.39±0.76 mol% of total fatty acids, respectively) was markedly higher than that in CE (0.44±0.07 vs. 0.92±0.26), whereas that of 18∶2t was nearly the same in all three fractions. The proportions of palmitic, stearic, arachidonic, and eicosapentaenoic acids in TG, CE, and PL and that of oleic acid in TG and CE were decreased when compared with the baseline value. In contrast, the proportion of palmitoleic acid in TG and PL and that of linoleic acid in PL increased on the TRANS diet. After consumption of the OLEIC diet, the proportion of oleic acid increased in all three lipid fractions analyzed, and the percentage increase was nearly the same in all fractions. In contrast, the proportions of 18∶1 t in TG and PL and 18∶2 t in TG and CE decreased when compared with the baseline value. In conclusion, a moderate increase in dietary trans fatty acids resulted in a marked incorporation into serum lipids and decreased the conversion of linoleic acid to its more unsaturated long-chain metabolites. Analysis of 18∶1 t from serum TG and PL seems to reflect reliably the dietary intake of this fatty acid.     

Metabolic Syndrome Affects Fatty Acid Composition of Plasma Lipids in Obese Prepubertal Children

The aim of the present study was to assess the plasma fatty acid composition of the total plasma lipids and lipid fractions in obese prepubertal children with and without metabolic syndrome (MS). Thirty-four obese prepubertal children were recruited: 17 who met MS criteria and 17 who did not; and twenty prepubertal children of normal weight. MS characteristics, insulin resistance (by homeostasis model assessment [HOMA-IR]), and plasma adiponectin (by radioimmunoassay) were recorded. Separation of lipid fractions was performed by liquid chromatography and the concentration of fatty acids in total plasma lipids and fractions was determined by gas-liquid chromatography. Concentrations of 16:1n-7, 16:1n-9, 18:3n-3, 22:6n-3, and n-3 PUFA in total plasma lipids (P < 0.05) and of 16:0, 16:1n-7, 18:1n-9, 18:2n-6, and n-6 PUFA in triacylglycerols (TG) (P < 0.05) were significantly higher in obese MS versus normal-weight children. Increased risk of MS was positively associated with plasma concentration of 16:1n-7 and negatively associated with proportion of 20:4n-6 (OR 2.76; P = 0.004; OR 0.56, P = 0.030, respectively). Saturated FA in TG were associated with HOMA-IR (R = 0.349, P = 0.017) and 22:5n-6 with adiponectin (R = 0.336, P = 0.05). In conclusion, increased concentrations of 16:1n-7 and decreased proportions of 20:4n-6 and 22:5n-6 in plasma lipids appear to be early markers of MS in children at prepubertal age.