Comparison of the Lipid Content,Fatty Acid Profile and Sterol Composition in Local Italian and Commercial Royal Jelly Samples

Royal jelly (RJ) is a beehive product that has gained a significant scientific and commercial interest due to its healthy properties. In the present study, lipid content, fatty acid profile and phytosterol amount were determined in eight local and four commercial pure RJ samples. A mixture of diethyl ether/isopropanol 50/1 (v/v) was chosen to extract fat matter from RJ. Lipid amounts ranged from 2.3 and 7.2 % and from 2.0 to 3.2 % of the fresh product in local and commercial RJ, respectively. Fourteen fatty acids and three phytosterols were identified. About 70 % of the total fatty acids consisted of (E)‐10‐hydroxy‐2‐decenoic and 10‐hydroxydecanoic acid. No significant difference was observed between local and commercial samples in regards to the relative amount of individual fatty acids. Sterols were in the range 179–701 and 329–1,097 mg kg^?1 of fat in local and commercial RJ, respectively. A significant difference (p ≤ 0.05) was observed within RJ types in regards to the 24‐methylenecholesterol fraction, amounting to 77 and 67 % of identified sterols in local and commercial products, respectively.     

Lipid Classes and Subclasses of Cold-Pressed and Solvent-Extracted Oils from Commercial Indian Niger (Guizotia abyssinica (L.f.) Cass.) Seed

Lipid classes and subclasses of cold-pressed and solvent-extracted (hexane and ethanol) oils from commercially available niger (Guizotia abyssinica (L.f.) Cass.) seeds were investigated. The oil yield of niger seeds obtained by cold pressing was 28.3 g/100 g while by hexane and ethanol extractions was 38.3 and 29.7 g/100 g respectively. The lipid classification of the extracted niger seed oils showed neutral lipids (65.9–95.5 %), glycolipids (2.7–24.6 %) and phospholipids (1.8–9.5 %). The acylglycerol composition of neutral lipids of extracted niger seed oils showed triacylglycerols (76.9–91.6 %), diacylglycerols (3.9–7.3 %) and monoacylglycerols (0.6–2.5 %). The fatty acid composition of tri-, di-, and monoacylglycerols of extracted niger seed oils showed linoleic acid (66.7–71.6 %) as the major fatty acid. The triacylglycerol composition of neutral lipids of extracted niger seed oils showed trilinolein (39.2–40.3 %) as the major triacylglycerol. The extracted niger seed oils contained 1289.9–6215.8 ppm of total phytosterols with β-sitosterol (41.9–43.7 %) as the major phytosterol. Acylated steryl glucoside (39.5–52.2 %) was the major glycolipid in extracted niger seed oils. Phosphatidylcholine (49.6 and 47.9 %) was the major phospholipid in cold-pressed and hexane-extracted niger seed oils and phosphatidylethanolamine (57.1 %) was the major phospholipid in ethanol-extracted niger seed oil. This is probably the first report on the variations in lipid classes and subclasses of Indian niger seed oil as affected by different modes of oil extraction.     

Lipid Content and Fatty Acid Composition of 15 Marine Fish Species from the Southeast Coast of Brazil

Lipid content and fatty acid composition were determined in edible meat of fifteen marine fish species caught on the Southeast Brazilian coast and two from East Antarctic. Most of the fish had lipid amounts lower than 10% of their total weight. Palmitic acid (C16:0) predominated, accounting for 54–63% of the total amount of saturated fatty acids. Oleic acid (C18:1n-9) was the most abundant (49–69%) monounsaturated fatty acid, and docosahexaenoic acid (DHA) was the predominant polyunsaturated fatty acid (PUFA), accounting for 31–84% of n-3 PUFA. n-3 PUFA level were highest in Antarctic fish meat, comprising 45% of the total fatty acid content, which consisted of mainly EPA (16.1 ± 1.5 g/100 g lipids) and DHA (24.8 ± 2.4 g/100 g lipids). The amounts of EPA + DHA in g/100 g of lipids on the Southeast Brazilian coast and Antarctic fish species investigated were found to be similar: 42.0 ± 1.7 for Bonito cachorro, 41.0 ± 2.3 for Atum, and 39.4 ± 1.8 for peixe porco, respectively. All the studied species exhibited an n-3/n-6 ratio higher than 3, which confirms the great importance of Southeast Brazilian coast fish as a significant dietary source of n-3 PUFA.     

Potential Development of Value-Added Fishery Products in Underutilized and Commercial Fish Species: Comparative Study of Lipid Quality Indicators

In this study, proximate and fatty acid composition in the edible flesh of eight underutilized and five commercial freshwater fish species were compared in order to evaluate the potential of these fish for development of functional value-added fishery products. The lipid content (% dry weight basis) of investigated fish species ranged from 3.44 to 9.25 in underutilized and 3.73–7.68 in commercial species. In comparison with underutilized fish species, commercial species had higher levels of protein (P < 0.05). The high proportion of EPA+DHA was found with Goldfish (524 mg/100 g flesh), Wels (422 mg/100 g flesh), and Crucian carp (354 mg/100 g flesh), all of which belonged to underutilized group. All studied fish (save Lenkoran) showed values higher than the minimum recommended DHA/EPA value (0.45). The ratios of n-6/n-3 found in this study were much lower (save Goatfish) than those cited as a harmful value (4.0 as the maximum value). The PUFA/SFA value of the present fish samples was higher at 1.57 for Goatfish, 1.02 for Lenkoran, 0.68 for Wels, all of these fish belonging to the underutilized group. The highest atherogenic and thrombogenicity index values were generally obtained for commercial species. It seems in respect of comparability of these lipid quality indicators, the underutilized fish species could be highly recommended as an important source of polyunsaturated fatty acids and Max-EPA products for humans consumption.     

Changes in Tissue Lipid and Fatty Acid Composition of Farmed Rainbow Trout in Response to Dietary Camelina Oil as a Replacement of Fish Oil

Camelina oil (CO) replaced 50 and 100 % of fish oil (FO) in diets for farmed rainbow trout (initial weight 44 ± 3 g fish^?1). The oilseed is particularly unique due to its high lipid content (40 %) and high amount of 18:3n‐3 (α‐linolenic acid, ALA) (30 %). Replacing 100 % of fish oil with camelina oil did not negatively affect growth of rainbow trout after a 12‐week feeding trial (FO = 168 ± 32 g fish^?1; CO = 184 ± 35 g fish^?1). Lipid and fatty acid profiles of muscle, viscera and skin were significantly affected by the addition of CO after 12 weeks of feeding. However, final 22:6n‐3 [docosahexaenoic acid (DHA)] and 20:5n‐3 [eicosapentaenoic acid (EPA)] amounts (563 mg) in a 75 g fillet (1 serving) were enough to satisfy daily DHA and EPA requirements (250 mg) set by the World Health Organization. Other health benefits include lower SFA and higher MUFA in filets fed CO versus FO. Compound‐specific stable isotope analysis (CSIA) confirmed that the δ¹³C isotopic signature of DHA in CO fed trout shifted significantly compared to DHA in FO fed trout. The shift in DHA δ¹³C indicates mixing of a terrestrial isotopic signature compared to the isotopic signature of DHA in fish oil‐fed tissue. These results suggest that ~27 % of DHA was synthesized from the terrestrial and isotopically lighter ALA in the CO diet rather than incorporation of DHA from fish meal in the CO diet. This was the first study to use CSIA in a feeding experiment to demonstrate synthesis of DHA in fish.     

Changes in Lipid and Fatty Acid Composition During Intramacrophagic Transformation of <Emphasis Type="Italic">Leishmania donovani</Emphasis> Complex Promastigotes into Amastigotes

Leishmania sp., are trypanosomatid parasites that are phagocytized by human and animal macrophages. Transformation from the vector promastigote stage to the intracellular amastigote host cell stage is mandatory, since development in the host depends on the internalization of the parasite. We identified and analyzed the lipids involved in the promastigote to amastigote transformation process in the Leishmania donovani complex. Four lipid classes, phospholipids, free fatty acids, triglycerides and sterols were studied. The derivatization method of Bligh and Dyer was used to establish the fatty acid composition in each stage of the parasite. To stay within the context of Leishmania infection, we used amastigotes extracted from macrophages after experimental in vitro infection. The purification process was checked by electronic microscopy, the absence of major contamination by host-cell debris and a correct purification yield validated our experimental model. Our results show that free fatty acids and cholesterol increased, whereas triglycerides and ergosterol decreased during the transition between promastigotes to amastigotes. With respect to phospholipid classes, we found increased proportion of sphingomyelin and phosphatidylserine and lowered proportion of phosphatidylinositol and lysophosphatidylethanolamine. Regarding fatty acid composition, a significant increase of n-7 fatty acids was observed in amastigotes. Overall, the total n-6 fatty acids were decreased in PL. Several of the changes were also observed in TG and free fatty acids. Particularly, n-7 fatty acids and 20:4n-6 were highly increased, whereas n-9 fatty acid and n-6 precursors decreased.     

Chemical Composition and Ability of Essential Oils from Six Aromatic Plants to Counteract Lipid Oxidation in Emulsions

Essential oils with antioxidant properties are of increasing interest in West Africa where there are many antioxidant rich plants. The objective of this study was to determine the essential oil extracted from six native plants (Lippia multiflora, Lippia rugosa, Monodora tenuifolia, Ocimum gratissimum, Pimenta racemosa, Cymbopogon citratus) extracted by hydrodistillation from local plants in Benin. These samples were also evaluated for their antioxidant capacity using the conjugated autoxidizable triene (CAT) assay performed in stripped tung oil-in-water emulsion. The essential oil of P. racemosa, containing high amounts of chavicol (10.3 %) and eugenol (54.5 %), showed the strongest antioxidant activity, followed by that from O. gratissimum containing large amounts of thymol (50.2 %). The essential oil extracted from M. tenuifolia exhibited a moderate antioxidant activity. This essential oil is primarily composed of sesquiterpene alcohols such as α-cadinol (20.5 %), its isomer, α-muurolol (14.7 %), and germacrene D-4-ol (16.8 %). Essential oils from L. multiflora, L. rugosa and C. citratus oils showed poor ability to protect tung oil from oxidation. Finally, essential oils containing phenolic compounds and, in a lesser extent, sesquiterpene alcohols, exhibited the highest CAT values indicating that these compounds are the key determinants of the antioxidant activity of these essential oils in oil-in-water emulsions.     

First Investigation in the Biochemical Analysis of the Invasive Crab <Emphasis Type="Italic">Portunus segnis</Emphasis> from Tunisian Waters

The invasive Portunus segnis, an atlantic species, was recently recorded in Tunisian waters. Since its record in the Gulf of Gabes, no studies have been carried out about the biochemical analysis of this alien species. In this context, our study aims to evaluate the fatty acid profile, lipid classes (neutral and polar), and nutritional value of breast of this invasive species. Specimens sampled from the gulf of Gabes were found to be rich in protein and oil, with significant differences between sexes. The level of saturated, monounsaturated, and polyunsaturated fatty acids in neutral and polar showed a significant difference between sexes. Saturated fatty acids were significantly higher in male P. segnis compared to the female. Docosahexaenoic (DHA), eicosapentaenoic (EPA), and arachidonic (ARA) were the most predominate polyunsaturated fatty acids (PUFA) in all oil classes. Oleic (C18:1) and Palmitoleic (C16:1) were the most abundant in monounsaturated. Palmitic (C16:0) and Stearic (C18:0) were the major saturated fatty acids. Consequently, the breast of P. segnis was a valuable source of high oil quality: It is rich in essential fatty acids and has an important n-3/n-6 ratio in both male and female blue crab. Therefore, the atherogenicity and the thrombogenicity were also evaluated, showing that P. segnis is a shellfish of greater value for human consumption in Tunisia.     

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.     

Determination of Substrate Preferences for Desaturases and Elongases for Production of Docosahexaenoic Acid from Oleic Acid in Engineered Canola

Production of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in plant seed oils has been pursued to improve availability of these omega‐3 fatty acids that provide important human health benefits. Canola (Brassica napus), through the introduction of 10 enzymes, can convert oleic acid (OLA) into EPA and ultimately DHA through a pathway consisting of two elongation and five desaturation steps. Herein we present an assessment of the substrate specificity of the seven desaturases and three elongases that were introduced into canola by expressing individual proteins in yeast. In vivo feeding experiments were conducted with 14 potential fatty acid intermediates in an OLA to DHA pathway to determine the fatty acid substrate profiles for each enzyme. Membrane fractions were prepared from yeast expression strains and shown to contain active enzymes. The elongases, as expected, extended acyl‐CoA substrates in the presence of malonyl‐CoA. To distinguish between enzymes that desaturate CoA‐ and phosphatidylcholine‐linked fatty acid substrates, we developed a novel in vitro method. We show that a delta‐12 desaturase from Phytophthora sojae, an omega‐3 desaturase from Phytophthora infestans and a delta‐4 desaturase from Thraustochytrium sp., all prefer phosphatidylcholine‐linked acyl substrates with comparatively low use of acyl‐CoA substrates. To further validate our method, a delta‐9 desaturase from Saccharomyces cerevisiae was confirmed to use acyl‐CoA as substrate, but could not use phosphatidylcholine‐linked substrates. The results and the assay methods presented herein will be useful in efforts to improve modeling of fatty acid metabolism and production of EPA and DHA in plants.     

The Influence of Polyunsaturated Fatty Acids on the Phospholipase D Isoforms Trafficking and Activity in Mast Cells

The impact of polyunsaturated fatty acid (PUFA) supplementation on phospholipase D (PLD) trafficking and activity in mast cells was investigated. The enrichment of mast cells with different PUFA including α-linolenic acid (LNA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), linoleic acid (LA) or arachidonic acid (AA) revealed a PUFA-mediated modulation of the mastoparan-stimulated PLD trafficking and activity. All PUFA examined, except AA, prevented the migration of the PLD1 to the plasma membrane. For PLD2 no PUFA effects on trafficking could be observed. Moreover, PUFA supplementation resulted in an increase of mastoparan-stimulated total PLD activity, which correlated with the number of double bonds of the supplemented fatty acids. To investigate, which PLD isoform was affected by PUFA, stimulated mast cells were supplemented with DHA or AA in the presence of specific PLD-isoform inhibitors. It was found that both DHA and AA diminished the inhibition of PLD activity in the presence of a PLD1 inhibitor. By contrast, only AA diminished the inhibition of PLD activity in the presence of a PLD2 inhibitor. Thus, PUFA modulate the trafficking and activity of PLD isoforms in mast cells differently. This may, in part, account for the immunomodulatory effect of unsaturated fatty acids and contributes to our understanding of the modulation of mast cell activity by PUFA.     

Parenteral Lipid Emulsions in Guinea Pigs Differentially Influence Plasma and Tissue Levels of Fatty Acids,Squalene, Cholesterol,and Phytosterols

Lipid emulsions are made by mixing vegetable and/or fish oils with egg yolk and contain different types and amounts of fatty acids and sterols. This study assessed the effects of oral diet, soybean oil (SO)-, fish oil (FO)-, a mixture of olive and soybean oil (OOSO)-, and a mixture of fish, olive, coconut, and soybean oil (FOCS)-based emulsions on plasma triacylglycerols and plasma and tissue fatty acid and sterol content following acute and chronic intravenous administration in the guinea pig. Upon acute administration, peak triacylglycerols were highest with SO and lowest with OOSO. Upon chronic administration, the plasma triglyceride levels did not increase in any group over that of the controls. Fatty acid levels varied greatly between organs of animals on the control diets and organs of animals following acute or chronic lipid administration. Squalene levels increased in plasma following acute administration of OOSO, but plasma squalene levels were similar to control in all emulsion groups following chronic administration. Total plasma phytosterol levels were increased in the SO, OOSO, and FOCS groups following both acute and chronic infusions, whereas phytosterols were not increased following FO infusion. Total phytosterol levels were higher in liver, lung, kidney and adipose tissue following SO and OOSO. Levels were not increased in tissues after FO and FOCS infusion. These results indicate that fatty acid and sterol contents vary greatly among organs and that no one tissue reflects the fatty acid or sterol composition of other tissues, suggesting that different organs regulate these compounds differently.