Neutral Lipid Fraction Research Articles

Fatty acid composition, TLC screening, ATR-FTIR analysis, anti-cholinesterase activity, and in vitro cytotoxicity to A549 tumor cell line of extracts of 3 macroalgae collected in Madeira

Three macroalgae collected at Madeira Island were included in this study to determine their potential for drug, nutraceutical, food, or supplement application. Fatty acid content was higher in Zonaria tournefortii (12.32 mg g−1 dw) with 16.58% of PUFAs, eicosapentaenoic acid (C20:5ω3), and arachidonic acid (20:4ω6) having concentrations of 2.59 and 1.17%, respectively. The anti-thrombogenic and anti-atherogenicity potential was higher for Z. tournefortii due to relevant fatty acids in the biochemical composition this macroalgae. Lipid classes were assessed in the lipid extract and neutral lipids (NL) were in higher yield in Asparagopsis taxiformis (51.16%) and lower in Z. tournefortii (26.96%). The glycolipids (GL) were between 36.03 and 16.11% in Z. tournefortii and Ulva lactuca. Phospholipids (PL) fraction varied from 35.91 and 31.60% in A. taxiformis and Z. tournefortii. TLC screening identified that U. lactuca contains phytol and cholesterol in its NL, digalactosyldiacylglycerol in its GL, and cardiolipin and L-α-phosphatidylcholine in its PL. Zonaria tournefortii contains phytol and cholesterol in its NL classes, and the PL classes contain L-α-phosphatidylethanolamine and 1-(3-sn-phosphatidyl)-rac-glycerol. The macroalgae A. taxiformis revealed cholesterol in its NL fraction and the same phospholipids as Z. tournefortii in its PL fraction. ATR-FTIR analysis enabled a “fingerprint” spectra and important sulfation absorption bands were identified, revealing the functional polysaccharides within these macroalgae. Anti-cholinesterasic activity was assessed in A. taxiformis, with a low IC50 for AChE (8.92 ± 0.43 μg mL−1) and BuChE (13.96 ± 0.32 μg mL−1), demonstrating dual inhibitory activity, justifying the interest to identify the active principle which may be the scaffold of a novel drug.

True lipases beside phospholipases contribute to walnut kernel viability loss during controlled deterioration and natural aging

Little is known on the role of true lipases in aging of orthodox seeds. Walnut (Juglans regia L.) kernels rich in triacylglycerol stores lose viability after storage however, data on lipolytic activities and their correlation to kernel viability loss are lacking. Extracts from mature kernels contained acid (pH 5.0) and alkaline (pH 9.0) lipases, phospholipase A2 and fatty acyl-esterase activities. Kernels with moisture contents of 6, 15 and 20% were subsequently incubated for 3 and 6 days at 45 °C for controlled deterioration. Viability loss was greatest in kernels with 20% moisture content after 6 days. Lipase and phospholipase A2 activities increased but total lipid declined as kernels lost viability. Pre-treatements with diphenylmethyl-phosphanate or 1-butanol which specifically inhibited oil body mobilization and phospholipase D, respectively, inhibited viability loss of kernels after controlled deterioration. Diphenylmethyl-phosphanate inhibited in vitro lipase activity and kernels treated with this chemical also had reduced lipase activity. Declined kernel viability after one year storage was also associated with the increased lipase activities and the accumulation of free fatty acids in the neutral lipid fraction. Cyanide application increased germination and fatty acyl-esterase activity of non-aged kernels but resulted in viability loss of one-year stored kernels. Thus, the increased activities of lipases beside phospholipase might result in walnut kernel viability loss at higher temperature and moisture content while fatty acyl-esterase activity may be a marker of kernel ongoing metabolic activity.

Study on the fatty acid profile of phospholipid and neutral lipid in Hanwoo beef and their relationship to genetic variation.

Maize which has very high omega-6 fatty acid content has been used as a main feed grain for Hanwoo beef production to increase marbling, and thus omega-6 to omega-3 fatty acids ratio in Hanwoo beef is expected to be biased. To elucidate the current status of omega fatty acids ratio in Hanwoo beef, fatty acid profiles of neutral lipid and phospholipid fraction were analyzed separately using 55 Hanwoo steers’ longissimus dorsi muscle slaughtered at Pyeongchang, Korea from Oct. to Nov. 2015. In addition, an association study was conducted to evaluate associations between single nucleotide polymorphism (SNP) markers from references and omega fatty acid profiles in phospholipid of Hanwoo beef samples using analysis of variance (ANOVA). In neutral lipid fraction, composition of saturated and monounsaturated fatty acids was higher and polyunsaturated fatty acids was lower compared to those in phospholipid fraction. The mean n-6/n-3 ratios of Hanwoo were 56.059 ± 16.180 and 26.811 ± 6.668 in phospholipid and neutral lipid, respectively. There were three SNPs showing statistically significant associations with omega fatty acid content. GA type of rs41919985 in fatty acid synthase (FASN) was significantly associated with the highest amount of C20:5 n-3 (p = 0.031). CC type of rs41729173 in fatty acid-binding protein 4 (FABP4) was significantly associated with the lowest amount of C22:2n-6 (p = 0.047). AG type of rs42187261 in FADS1 was significantly linked to the lowest concentration of C20:4 n-6 (p = 0.044). The total n-6/n-3 ratio of the steer which has all four SNP types in above loci (27.905) was much lower than the mean value of the total n-6/n-3 ratio in phospholipid of the 55 Hanwoo steers (56.059 ± 16.180). It was found that phospholipid and neutral lipid of Hanwoo have very high n-6/n-3 ratios compared to the reported data from different cow breeds. Four SNPs in genes related with fatty acid metabolism showed significant associations with the fatty acid profile of phospholipid and may have potential as SNP markers to select Hanwoo steers in terms of n-6/n-3 balance in the future.

The in vitro antithrombotic properties of ale, lager, and stout beers

The in vitro antithrombotic properties of polar lipid microconstituents of three Irish beers (ale, larger, and stout) have been assessed against platelet-activating factor-induced platelet aggregation. Total lipid (TL) extracts were obtained using the Bligh and Dyer method and each beer was separated into the organic phase and hydromethanolic phase. The total polar lipid (TPL) and total neutral lipid (TNL) fractions of the organic phase and hydromethanolic phase of each beer were obtained using a counter-current distribution. The TL, TNL, and TPL extracts of each phase of each beer were measured for their capacity to inhibit platelet-activating factor-induced platelet aggregation. The low IC50 values obtained suggest that all three beers contain potent polar lipids that can inhibit platelet-activating factor-induced platelet aggregation. The fatty acid composition of the organic phase TPL extracts were measured using gas chromatography-mass spectrometry. The organic phase total polar lipid extracts were further fractionated using thin-layer chromatography (TLC) and the antithrombotic bioactivities of these TLC bands were measured. This data suggested that the TLC bands corresponding to phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, and cardiolipin were the most active phospholipids in the total polar lipids of the organic phase. These promising results indicate that beer consumption may provide antithrombotic effects.

Seeds of Centranthus ruber and Valeriana officinalis Contain Conjugated Linolenic Acids with Reported Antitumor Effects.

Conjugated linolenic acids (CLNs) are naturally occurring fatty acids that are believed to have anticancer properties. In this study, we examined various plant seeds from herbs to discover seed oils containing CLNs. The ultraviolet spectra of total lipids from these seeds were measured. An absorption maximum around 270 nm was observed in seed oils belonging to the Valerianaceae family (Centranthus ruber and Valeriana officinalis). When the fatty acid compositions of these seed oils were measured, CLNs were detected. By silica column chromatography, neutral lipids (NLs), glycolipids, and phospholipids were eluted from seed oils of C. ruber and V. officinalis. Then, fatty acid compositions of these fractions were measured. This revealed that most of the CLNs in these seed oils existed in the NL fraction. When the NL fractions of these seed oils were reacted with lipase, CLNs showed good sensitivity to lipase hydrolysis. This suggested that the CLNs in the seed oils of C. ruber and V. officinalis existed predominantly at the sn-1,3 position of triacylglycerol and less at the sn-2 position. These results suggested that the CLNs from the seed oils of C. ruber and V. officinalis could easily be taken up by cancer cells as free fatty acids and had good potential as antitumor substances.

Translocation and de novo synthesis of eicosapentaenoic acid (EPA) during nitrogen starvation in Nannochloropsis gaditana

The microalga Nannochloropsis gaditana is known for accumulating fatty acids, including the commercially interesting eicosapentaenoic acid (EPA) within the polar lipids (PL) and neutral lipids (NL). During microalgal growth EPA is mainly present in the PL. Upon nitrogen starvation N. gaditana accumulates large amounts of TAG in lipid bodies. The neutral lipid fraction will mainly consist of triacylglycerol (TAG). When expressed per total cell dry weight, the NL-localized EPA increased while the PL-localized EPA decreased, suggesting that EPA is translocated from the PL into the NL lipids during nitrogen starvation. Here, we elucidated the origin of EPA in NL of N. gaditana by firstly growing this microalga under optimal growth conditions with 13CO2 as the sole carbon source followed by nitrogen starvation with 12CO2 as the sole carbon source. By measuring both 12C and 13C fatty acid isotope species in time, the de novo synthesized fatty acids and the already present fatty acids can be distinguished. For the first time, we proved that actual translocation of EPA from the PL into the NL occurs during nitrogen starvation of N. gaditana. Next to being translocated, EPA was synthesized de novo in both PL and NL during nitrogen starvation. EPA was made by carbon reshuffling within the cell as well. EPA was the main fatty acid translocated, suggesting that the enzyme responsible for fatty acid translocation has a high specificity for EPA.

Simultaneous extraction and fractionation of omega-3 acylglycerols and glycolipids from wet microalgal biomass of Nannochloropsis gaditana using pressurized liquids

Microalgae are primary producers of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids in marine environment and so they are considered promising alternative sources of omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs). Nannochloropsis gaditana is an oleaginous cultivated microalga with an important content of triglycerides and polar lipids which include interesting EPA amounts. In this work, new methods using pressurized liquids for simultaneous extraction and fractionation of neutral and polar lipids from wet microalgal biomass are proposed. Pressurized liquid extraction (PLE) using different solvents, combined or not with pre-treatment of the alga with enzymes, allows one to enrich and fractionate neutral and polar lipids such as triacylglycerols, diacylglycerols, monoacylglycerols, free fatty acids and glycolipids. The use of enzymatic pre-treatment did not show a significant increase in the lipid yield, though a different fractionation of the microalgal lipids was achieved. PLE with a single solvent (hexane at 120 °C) rendered a lipid yield of 17.6%, slightly higher than the traditional Folch method (16.9%), but with a less-toxic solvent and faster extraction technique. In addition, PLE with hexane attained a high triacylglycerols fraction (17.2% ± 3.0). The optimal four-step sequential method developed using pressurized liquids reached a good fractionation characterized by a high content of glycolipids (29.2% ± 2.0) and monoacylglycerols (17.3% ± 1.9), with a lipid recovery of 14.0% ± 1.3 for the original biomass. The analysis by GC/MS of fractions obtained with each method and solvent combination, showed a different composition in fatty acids of fractionated neutral and polar lipid species, especially in saturated and omega-3 fatty acids. Therefore, the proposed fast PLE methods allow the simultaneous extraction and fractionation of the neutral and polar lipids of Nannochloropsis gaditana and produce enriched EPA fractions (up to 53%).

Bonefish (Albula vulpes) oocyte lipid class and fatty acid composition related to their development

Bonefish (Albula vulpes) are a valuable fishery resource of tropical and subtropical ecosystems worldwide. Despite their importance, there is limited information on bonefish life history and ecology. The present study aims to describe, for the first time, oocytes development and their lipid characteristics in wild bonefish during the reproductive season in different tidal flat locations in Grand Bahama Island, Bahamas. Our results have shown that Bonefish follow group-synchronous ovarian development and produce lipid-rich eggs [total lipid (TL) content was >26% of wet mass (WM)]. The major lipid class was a neutral lipid: the wax esters and steryl esters (WE-SE; >48% of TL), suggesting their use to support buoyancy and/or energy storage. Fatty acid (FA) composition of bonefish oocytes was characterized by high levels of monoenes in the neutral lipid fraction (i.e. 16:1 and 18:1n-9) indicating their probable role as energy fuel. However, the most abundant fatty acids in the polar lipids were docosahexaenoic acid (DHA; 22:6 n-3 > 15% of total polar FA), eicosapentaenoic acid (EPA; 20:5 n-3 > 13% of total polar FA) and arachidonic acid (ARA; 20:4 n-6 > 4% of total polar FA) which were selectively conserved among the tidal flat locations, suggesting their importance as essential constituents of cell membranes during the development of bonefish oocytes. Our results bring useful information concerning the reproductive physiology of bonefish and not only serve as a benchmark for determining the nutrient requirements to produce high quality eggs from bonefish captive broodstock, but also will help establish meaningful management practices for this species.

Involvement of fatty acids in the response to high CO2 and low temperature in harvested strawberries

Fatty acids (FAs) play important roles in membrane fluidity, energy status and the production of specific FA-dependent esters. However, little is known about the modifications in FAs induced by high CO2 that can improve fruit quality and prevent the disorders associated with storage at low temperature. For this purpose, total, free and esterified FAs in neutral and polar lipid fractions were characterized and quantified and their relationship with straight-chain esters was examined in strawberries treated with high doses of CO2 and different times of exposure during early storage at 0 °C. In strawberries stored without added CO2 (T1), storage at 0 °C led to an imbalance in the saturated/unsaturated ratio of polar lipids, mainly due to the decrease in the amount of saturated fatty acids (SFA). In addition, a decrease in the amount of free polyunsaturated fatty acids (PUFA) linked to a prevalence of butanoates and hexanoates esterified to long alcohols was observed. A strong negative correlation (P ≤ 0.01; r ≥ 0.7) between butanoate esters and free PUFA was quantified. In contrast, the application of 2 d 20 kPa CO2 treatment (T2), increased the amount of PUFA from the neutral and polar fractions, with a preference for α-linolenic acid (18:3n3) which results in a rise in the 18:3/18:2 ratio, and which can confer membrane stability and fluidity. Furthermore, our results also showed a strong positive correlation (P ≤ 0.01; r ≥ 0.75) between α-linolenic acid (18:3n3) of polar lipids and some ethyl esters that contribute mostly to the aroma in strawberries. However, 3 d 40 kPa CO2 treatment (T4) depleted the content of FAs from all the lipid fractions in association with deficit ATP levels and an increased lipid peroxidation. These results suggest an active lipid breakdown which could play a causal role in the reported increased leakage of cellular water into intercellular air spaces in stressed-CO2 fruit. Taken together, our results provide new insights into the beneficial effect of 2 d 20 kPa CO2 treatment at 0 °C on the enhancement of PUFA in the polar lipid fraction and on the emission of esters other than ethyl acetate, which could improve membrane fluidity and could contribute to enriching aroma in strawberries.

Effects of nutrients and processing on the nutritionally important metabolites of Ulva sp. (Chlorophyta)

In consideration that, fatty acids bound within phospholipids may exhibit greater levels of bioavailability than neutral lipids, we investigated the effect of nutrient starvation on the phospholipid content and composition of cultivated Ulva biomass. Furthermore, we explored the simultaneous effects on the pigment and phenolic profiles and then correlation analysis to anti-oxidant and anti-inflammatory activity. High nutrient cultivation (nitrogen replete) provided a biomass with desirable n-6/n-3 (0.3) and 18:2n-6/18:3n-3 (0.5) ratios and beneficial 18:4n-3, 20:5n-3, 22:5n-3 fatty acids. These fatty acids dominated the abundant neutral lipid fraction, which comprised 62% of the lipid extract. The remaining phospholipids (38%) were characterised by high 16:0 (49.6%), 18:1n-7 (14.6%) and 18:3n-3 (13.6%) fatty acids. Nutrient-depleted samples had a 3-fold higher total fatty acid (TFA) content (12.05 mg·g−1 d.w, p < 0.0001) compared to nutrient replete samples (3.35 mg·g−1 d.w.). This occurred mostly within the neutral fraction, which represented 88% of the total lipids and the fatty acids 16:0 (4.02 ± 0.15 mg·g−1), 18:1n-7 (1.79 ± 0.06 mg·g−1), 18:2n-6 (2.30 ± 0.08 mg·g−1) and 18:3n-3 (1.09 ± 0.03 mg·g−1 d.w). Nutrient replete biomass yielded 1.5 mg·g−1 total chlorophyll, 0.1 mg·g−1 carotenoids and 1.6 mg·g−1 phenolics, whilst low nutrient growth conditions reduced the presence of pigments by 98%, phenolics by 34% and anti-oxidant activity by 87%. Significantly higher yields of pigment and phenolics were obtained using 95% ethanol for the extraction process, whilst acetone extracts were characterised by a higher proportion of carotenoids. All extracts from cultivated Ulva samples inhibited nitric oxide (NO) (≥81%) with acetone extracts demonstrating higher inhibition (94–97%) than 95% ethanol extracts (81–90%) with no significant effects observed between the two treatments. Thus, Ulva cultivated under high nutrients offers a sustainable source of potential biomass for n-3 PUFA, pigments and phenolics with attributable anti-oxidant and anti-inflammatory activity.

Radical scavenging activity of lipids from seaweeds isolated by solid-liquid extraction and supercritical fluids

In vitro antioxidant activities of the lipid fractions from two selected seaweeds, Solieria chordalis and Sargassum muticum were investigated according to the extraction methods. The activity of neutral lipids, glycolipids and phospholipids, thanks to extraction by chloroform/methanol (1/1 v/v; CM) mixture, pure supercritical carbon dioxide (sc-CO2), supercritical carbon dioxide with 2% of ethanol (sc-CO2 + EtOH 2%) and supercritical carbon dioxide with 8% of ethanol as co-solvent (sc-CO2 + EtOH 8%), were studied using DPPH radical scavenging assays. All the lipid classes demonstrated a free radical scavenging activity at the concentration of 1 mg/ml. The best scavenging activity (86.6 ± 5.7%) was obtained when the neutral lipid fraction was extracted from S. chordalis with a CM mixture. The neutral lipid fraction extracted with sc-CO2 showed a lower activity than those obtained with solvents. However, the addition of ethanol in sc-CO2 did not affect the antioxidant activity of neutral lipids fixed at around 16% of radical scavenging. For S. muticum, the activity of glycolipids (50.9 ± 0.8%) and phospholipids (48.4 ± 1.6%) obtained with sc-CO2 were twice as large as that of fractions obtained with CM, 29.6 ± 3.4% and 28.0 ± 4.2%, respectively. The activity of neutral lipids did not change with the extraction method with around 25% of radical scavenging. This is the first report of free radical scavenging activity of lipid classes obtained by supercritical carbon dioxide extraction from seaweeds.

Potential of Lentibacillus sp. NS12IITR for production of lipids with enriched branched-chain fatty acids for improving biodiesel properties along with hydrocarbon co-production.

Hypersaline environment is inhabited by array of microbes which have the potential to produce industrially important products. This study explored biomass and lipid production potential of the halophilic bacterium, strain NS12IITR which was isolated from Sambhar Lake, Rajasthan. Sequencing and phylogenetic analysis revealed that the bacterium belonged to genus Lentibacillus. The salient feature of the isolate is its ability to accumulate total cellular lipid up to 18.9 ± 0.45% of dry cell weight. In addition, trans-esterification of extracted lipid yielded 77.6 ± 5.56% of total esters as methyl ester of branched-chain fatty acids (BCFAs). To assess the nature of extracted lipid, lipid sample was fractionated on the silicic acid column, which demonstrated that 49.03 ± 1.35% of the total lipids was neutral in nature. Trans-esterification of the neutral lipid fraction yielded 60.62 ± 4.88% of total esters as methyl ester of BCFAs. Methyl esters of BCFAs were present in trans-esterified products of neutral as well as polar lipid fractions. Furthermore, the isolate produced hydrocarbons both extracellularly (C10-C30) and intra-cellularly (C15-C28). The concentration of extracellular hydrocarbon (21.11 ± 0.78mg/L) synthesized by strain NS12IITR is in close agreement with the yield reported from other hydrocarbon producing bacteria. This is hereby a first report on the co-production of lipids and hydrocarbon from a halophilic bacterium. The production of neutral lipid with high percentage of BCFAs and co-production of hydrocarbons makes the isolate NS12IITR a potential claimant for biofuel production.

Nematodes as Important Source for Omega-3 Long-Chain Fatty Acids in the Soil Food Web and the Impact in Nutrition for Higher Trophic Levels

PUFA (polyunsaturated fatty acids) content of food sources, in particular 3 long-chain PUFA with three or more double bonds, are considered essential for growth, reproduction, and neural development of higher animals. Surprisingly, and in contrast to aquatic ecosystems, 3 long-chain PUFA seem not widely available in terrestrial food webs. Far-reaching ideas indeed proclaim aquatic ecosystems as the principal source of these long-chain PUFA in the whole biosphere, including inhabitants of terrestrial ecosystems. Interestingly, de novo synthesis of 3 long-chain PUFA, which requires the presence of Δ12 (fat-2) and 3 (fat-1) desaturases absent in vertebrates, has been observed in nematodes, such as Caenorhabditis elegans. This raises the question if nematodes or other soil invertebrates present an important trophic link offering substantial supply in these valuable nutritional compounds in terrestrial food webs. This work followed the dietary routing of fatty acids of different C. elegans strains, including mutants defective in the PUFA biosynthesis, to two omnivorous Collembola species, Folsomia candida and Protaphorura fimata. The laboratory approach comprised microcosms offering binary links under various feeding conditions and analyzed growth, fecundity and dietary preference of consumers. Collembola did not prefer individual C. elegans strains as food source but they clearly reflected the PUFA-richness or -poorness of their nematode prey in their neutral lipid fraction. Moreover, Collembola did benefit from 3 long-chain PUFA rich diet, as shown by significant weight gain and increased number of laid eggs. Interestingly, the comparatively high PUFA-content of Collembola’s phospholipid fraction remained unchanged, even in response to almost PUFA-depleted nematode prey, suggesting that these Collembola species also possess the metabolic capability to de novo synthesize PUFA, including 3 long-chain forms. These findings broaden the basis of long-chain PUFA sources in terrestrial food webs and question the impact of aquatic ecosystems as principal source.

Impact of cryopreservation on lipid composition of reproductive cells of male sterlets (Acipenser Ruthenus L.)

Aim. To estimate the impact of low temperatures on the lipid composition of reproductive cells of male sterlets (Acipenser ruthenus L) in cryopreservation environment. Methods. The determination of sperm quality (color, consistence, concentration and motility of spermatozoa) was estimated by common biochemical methods using standard equipment. Thin-layer chromatography was used to reveal fi ve fractions of neutral lipids in the sperm of investigated fi sh, which were distributed on the plates as follows: the starting line demonstrated phospholipids, cholesterol, free fatty acids, triacylglycerol and ethers of cholesterol. The adaptive property of sperm was estimated by the level of spermatozoa survival prior to and after cryopreservation. Results. The obtained results of sterlet sperm activity prior to and after cryopreservation demonstrate high quality of native sperm and its considerable deterioration after freezing/thawing. Conclusions. The impact of low temperatures on the lipid composition of reproductive cells of male sterlets (Acipenser ruthenus L) in cryopreservation environment leads to impairments of the phospholipid bilayer of their membranes. It was established that during the thawing of frozen sperm cells which preserved their viability after cryopreservation their motility and capability of fertilizing an ovum were somewhat restored with slowing down of sperm cell motility.

Olive (Olea europaea L. cv. Galega vulgar) Seed Oil: A First Insight into the Major Lipid Composition of a Promising Agro‐Industrial By‐Product at Two Ripeness Stages

Olive seeds are promising industrial by‐products whose study acquires relevance both for valuing their biotechnological potential and for discriminating the origin and/or the edaphoclimatic conditions of olives. Herein, the fatty acid (FA) and triacylglycerol (TAG) profiles of total lipid extracts and neutral lipid fractions from olive seeds (Olea europaea L. cv. Galega vulgar), at two ripeness stages, are analyzed by mass spectrometry (MS)‐based approaches. In both olive seeds (green and ripe), the predominant FA are C18:1(n‐9) (56%), C18:2(n‐6) (17%), and C16:0 (18%). The seeds also contained the essential FA C18:3(n‐3) (0.11%). Ripeness led to a decrease of saturated FA and an increase of unsaturated FA. In total lipid extracts, major FA (C18:1(n‐9) and C18:0) could distinguish green from ripe olives (p &lt; 0.05). In neutral lipid fractions, besides major FA (C18:1(n‐9) and C16:0), minor ones (C14:0, C18:3(n‐3), C20:0, and C22:0) could distinguish ripeness stages (p &lt; 0.05). The relative amount of nine TAG is significantly different between green and ripe olives (p &lt; 0.05), of which six are minor TAG. Olive seeds and their oil are a good source of n‐9 monounsaturated FA, and n‐6 and n‐3 polyunsaturated FA, being n‐3 higher in ripe olives. The ripeness stage can be distinguished by minor FA and minor TAG using MS.Practical Applications: Considering the high proportion of unsaturated and essential FA that make up olive seeds/olive seed oil, and knowing how these proportions shift according to olive ripeness, will allow different industries to explore several potential applications of these promising agro‐industrial by‐products. Besides, profiling the FA and TAG composition of olive seed oil by MS‐based lipidomic approaches reveals that both the highest and the lowest abundant lipid molecules within these classes might be used as potential biochemical markers to discriminate these oils based on fruit ripeness stage.Olive seed oil is rich in mono‐ (56%) and in polyunsaturated (17%) fatty acids (FA). During ripeness, saturated FA decrease and unsaturated increase. Minor FA of neutral lipid fraction can distinguish green and ripe olive seed oils. Less abundant triacylglycerols allow discriminating seed oils from different ripeness stages. Based on its major lipid composition, olive seed oil has several potential applications within different industries.

Effect of slaughter age and feeding system on the neutral and polar lipid composition of horse meat

This study was undertaken to provide a thorough analysis of the neutral lipid (NL) and polar lipid (PL) fractions of horse meat that included the content and distribution of acyl and alkenyl moieties in foals under different rearing conditions. Two groups of crossbred horses were studied; the first group was selected from suckling foals produced under grazing conditions and slaughtered at 4 months of age (n=8), and the second group was selected from concentrate-finished foals and slaughtered at 12 months of age (n=7). There were significant differences related to the age and feeding practices of foals which affected the intramuscular (IM) fat content and the fatty acid (FA) composition of NL and PL fractions. Samples from suckling foals were leaner and provided the highest content of methylation products from the plasmalogenic lipids, and total and n-3 polyunsaturated fatty acid (PUFA). By contrast, the meat from concentrate-finished foals had a higher IM fat level resulting in a greater accumulation of 16:0 and total monounsaturated FAs in the NL fraction, whereas the muscle PL fraction retained a similar FA composition between both groups. Linolenic acid was preferentially deposited in the NL fraction, but linoleic acid and the long-chain n-3 and n-6 PUFAs were incorporated into the PL fraction where they served as cell membrane constituents and in eicosanoid formation.

Nutritional quality in terms of lipid content and fatty acid composition of neutral and polar lipids in the adductor muscle of the oyster Crassostrea gigas (Thunberg, 1794) farmed in the Bizert lagoon (Tunisia) in relation with sexual cycle and environmental settings

Monthly variations of fatty acid composition of the two fractions polar lipids (PL) and neutral lipids (NL) in the adductor muscle of cupped oyster Crassostrea gigas, were studied from May 2005 until June 2006 in the Bizert lagoon, related to environmental parameters and reproductive events. C. gigas showed a clear cycle of energy storage and utilization in the site of study. Total PL and NL content varied significantly during the year and showed a negative and significant correlation with the gametogenic condition index which can be explained by transfer of fatty acids from the adductor muscle to gonads to support the gametogenic cycle. Nevertheless, PL and NL have no significant correlations either with temperature or chlorophyll a registered in the site of study. The adductor muscle proved to be less influenced by chlorophyll a richness of the farming environment. The dominance of total polyunsaturated fatty acids (PUFAs) over the saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) in both PL and NL fractions was established throughout the period of study. Oysters analyzed were characterized by high levels of PUFAs n−3 and high n−3/n−6 PUFAs ratio in both PL and NL fractions. PUFAs n−3 and SFAs of PL and PUFAs and SFAs of NL, showed a negative and significant correlation between them. In fact, low temperature values produce generally an increase in the PUFAs percentages in order to maintain the fluidity of cell membranes. We deduce that annual variations of fatty acids content in PL and NL fractions of the adductor muscle of C. gigas seem to be in relation with the reproductive events. According to our results, the adductor muscle tissues were relatively poor in fatty acids (maximum values (% of dry weight) of PL and NL respectively were 2.04±0.33 and 1.75±0.9). Lipids fluctuations were not pronounced all over the period of study in the site of sampling due to low effects of the environment richness and phases of the sexual cycle which aspires the adductor muscle contents of fatty acids to support other organs in the gametogenic process. But this organ arrives despite its difficulties to maintain a high level of n−3/n−6 PUFA and having a good nutritional quality.

Potential of macroalgae for biodiesel production: Screening and evaluation studies

Nowadays, biofuel production is a fast expanding industry and is facing a growing dilemma about a feedstock source capable of keeping up with demand. Recently, macroalgae have been attracting a wide attention as a source for biofuel. In the present study, ten macroalgae were collected and screened as biodiesel feedstocks. As a result of their high biomass production and relatively high lipid content, Ulva lactuca, Padina boryana and Ulva intestinalis showed the highest significant lipids and fatty acid methyl esters (FAMEs) areal productivities among the studied species. Saturated fatty acids (SAFs) showed insignificant differences in the selected species, with noticeably significant higher polyunsaturated fatty acids (PUFAs) content in U.lactuca by 4.2 and 3 times, with respect to P.boryana and U.intestinalis, respectively. The recorded increase in PUFAs was attributed to higher content of C16:4n-3, C18:3n-3 and C18:4n-3. By lipid fractionation, P.boryana showed significant higher concentration of neutral lipids (37.7mgg-1 CDW, representing 46.7% of total fatty acids) in comparison to U.lactuca and U.intestinalis, which showed 16% and 17% lower neutral lipid fractions, respectively. In addition, biodiesel characteristics of the studied macroalgae complied with that of international standards. Furthermore, oil-free residual biomass can be readily converted into fermentable sugars or biogas due to its high carbohydrates content, which adds to the economics of macroalgae as biofuel feedstock. In conclusion, the present study confirmed that macroalgae represent an attractive alternative renewable feedstock for biodiesel and other biofuels.

Carbon Allocation in Rhodococcus jostii RHA1 in Response to Disruption and Overexpression of nlpR Regulatory Gene, Based on 13C-labeling Analysis.

Nitrogen lipid regulator (NlpR) is a pleiotropic regulator that positively controls genes associated with both nitrogen and lipid metabolism in the oleaginous bacterium Rhodococcus jostii RHA1. In this study, we investigated the effect of nlpR disruption and overexpression on the assimilation of 13C-labeled glucose as carbon source, during cultivation of cells under nitrogen-limiting and nitrogen-rich conditions, respectively. Label incorporation into the total lipid extract (TLE) fraction was about 30% lower in the mutant strain in comparison with the wild type strain under low-nitrogen conditions. Moreover, a higher 13C abundance (∼60%) into the extracellular polymeric substance fraction was observed in the mutant strain. nlpR disruption also promoted a decrease in the label incorporation into several TLE-derivative fractions including neutral lipids (NL), glycolipids (GL), phospholipids (PL), triacylglycerols (TAG), diacylglycerols (DAG), and free fatty acids (FFA), with the DAG being the most affected. In contrast, the nlpR overexpression in RHA1 cells under nitrogen-rich conditions produced an increase of the label incorporation into the TLE and its derivative NL and PL fractions, the last one being the highest 13C enriched. In addition, a higher 13C enrichment occurred in the TAG, DAG, and FFA fractions after nlpR induction, with the FFA fraction being the most affected within the TLE. Isotopic-labeling experiments demonstrated that NlpR regulator is contributing in oleaginous phenotype of R. jostii RHA1 to the allocation of carbon into the different lipid fractions in response to nitrogen levels, increasing the rate of carbon flux into lipid metabolism.

Fatty Acid Profile of Neutral and Polar Lipid Fraction of Wild Eggs and Hatchlings from Wild and Captive Reared Broodstock of Octopus vulgaris.

The culture of Octopus vulgaris is constrained by unsolved problems in paralarvae rearing, mainly associated to the unknown nutritional requirements of this species in early stages. In this article we studied the fatty acid profile (total, neutral, and polar lipid fractions) in wild eggs and wild hatchlings, collected in Gran Canaria (SW) (Spain) with artificial dens, in comparison to hatchlings obtained in captivity from broodstock fed on trash fish species. Total lipids were 11.5–13.5% dw, with the polar fraction representing a 70.6–75.5% of total lipid, with lower values in wild hatchling in comparison with captive ones. Docosahexaenoic acid (DHA) was the main component in neutral and polar fatty acid profile in all samples, underlying its importance in this species. Decreasing levels of saturates and arachidonic acid (ARA) from wild eggs to hatchlings, mainly associated to the polar fraction, suggest their use during embryonic development. In hatchlings, increasing levels of oleic acid in the neutral fraction and eicosapentaenoic acid (EPA) in the polar fraction, suggests their importance in hatchlings quality. Wild hatchlings showed in the polar fraction higher oleic acid and ARA, and lower DHA/ARA and EPA/ARA ratios in comparison with captive hatchlings, suggesting a difference in paralarvae nutritional status. These results suggest the importance of n-3 highly unsaturated fatty acids (HUFA), oleic acid, and ARA, presented in the adequate lipid fraction, in the diet of broodstock and paralarvae of O. vulgaris.