Fatty Acid Composition Of Neutral Lipids Research Articles

Taxonomy and diet determine the polar and neutral lipid fatty acid composition in deep-sea macrobenthic invertebrates

Taxonomy and diet determine the polar and neutral lipid fatty acid composition in deep-sea macrobenthic invertebrates

Effects of storage and handling on neutral lipid fatty acid profiles of two woodlice (Isopoda, Crustacea) species differing in size

Neutral lipid fatty acid (NLFA) analysis is a promising tool to investigate energy fluxes and basal resources of soil animal communities. This study aimed at investigating the effect of common handling and storage procedures in soil animal ecology on the NLFA composition and marker NLFAs. First, we tested the effect of the method of killing (by freezing and by drowning in diethylene glycol mixed with water; 1:1) on NLFA composition of the woodlouse Oniscus asellus. Additionally, we inspected the effect of two reference methods (direct freezing at −20 °C and storage in methanol at −80 °C with evaporating methanol prior to lipid extraction) after 4 and 12 months on the NLFA profile of O. asellus. We investigated the effect of the collection solution used in heat extraction of soil animals (water and glycol), storage fluids (saltwater, glycerine, ethanol and methanol) and storage time (4 and 12 months) on NLFA composition and common marker NLFAs of two Isopoda species differing in body size. The NLFA composition and marker fatty acids (FAs) did not differ between the methods of killing and between the two reference treatments but the amount of saturated FAs and the saturated-to-unsaturated FA ratio generally increased after 12 months indicating oxidation processes. Generally, the collection solution was of minor importance, whereas storage fluid and storage time strongly affected NLFA patterns. The NLFA profile of the larger species O. asellus was affected by storage in methanol and ethanol and to some extent in saltwater, while the NLFA profile of the smaller Trichoniscus pusillus was affected by each of the treatments. Notably, however, marker FAs of O. asellus and T. pusillus were not significantly affected by storing in glycerine even after 12 months in O. asellus. Therefore, if animals need to be stored prior to NLFA analysis for sorting and identification, storage in glycerine is advisable.

Neutral lipid fatty acid composition as trait and constraint in Collembola evolution.

Functional traits determine the occurrence of species along environmental gradients and their coexistence with other species. Understanding how traits evolved among coexisting species helps to infer community assembly processes. We propose fatty acid composition in consumer tissue as a functional trait related to both food resources and physiological functions of species. We measured phylogenetic signal in fatty acid profiles of 13 field‐sampled Collembola (springtail) species and then combined the data with published fatty acid profiles of another 24 species. Collembola fatty acid profiles generally showed phylogenetic signal, with related species resembling each other. Long‐chain polyunsaturated fatty acids, related to physiological functions, demonstrated phylogenetic signal. In contrast, most food resource biomarker fatty acids and the ratios between bacterial, fungal, and plant biomarker fatty acids exhibited no phylogenetic signal. Presumably, fatty acids related to physiological functions have been constrained during Collembola evolutionary history: Species with close phylogenetic affinity experienced similar environments during divergence, while niche partitioning in food resources among closely related species favored species coexistence. Measuring phylogenetic signal in ecologically relevant traits of coexisting species provides an evolutionary perspective to contemporary assembly processes of ecological communities. Integrating phylogenetic comparative methods with community phylogenetic and trait‐based approaches may compensate for the limitations of each method when used alone and improve understanding of processes driving and maintaining assembly patterns.

The effect of marine and non-marine phospholipid rich oils when fed to juvenile barramundi (Lates calcarifer)

An experiment was conducted to assess the response of juvenile barramundi (Lates calcarifer) to four diets containing either marine- or non-marine derived neutral lipid (NL) or polar lipid (PL) sources for eight weeks in a 2×2 factorial design. The four diets contained 8.2% added lipid composed of a 1% fish oil base with 7.2% test lipid (n−3 NL: Fish oil, n−3 PL: Krill oil, n−6 NL: Soybean oil, n−6 PL: Soybean lecithin). The results demonstrated that the different lipid sources (either n−3 or n−6 omega series from either NL or PL class) had significant effects on growth performance and feed utilisation with some interaction terms noted. Growth was negatively affected in the n−6 NL fish and the feed conversion (FCR) was highest in the n−6 PL fish. Digestibility of total lipid and some specific fatty acids (notably 18:2n−6 and 18:3n−3) were also negatively affected in the n−6 PL fish. Analysis of the whole body neutral lipid fatty acid composition showed that these mirrored those of the diets and significant interaction terms were noted. However, the whole body polar lipid fatty acids appeared to be more tightly regulated in comparison. The blood plasma biochemistry and hepatic transcription of several fatty acid metabolism genes in the n−6 PL fed and to a lesser extent in the n−6 NL fed fish demonstrated a pattern consistent with modified metabolic function. These results support that there are potential advantages in using phospholipid-rich oils however there are clear differences in terms of their origin. Statement of relevanceJuvenile barramundi may benefit from dietary phospholipid.

Comparative study of lipids and lipophilic constituents from separate organs of Ajuga turkestanica

Lipids from the fresh aerial part, flowers, roots, and seeds of Ajuga turkestanica were studied. The contents, classes, and fatty-acid compositions of neutral lipids, glycolipids, and phospholipids of extracts and the compositions of free and bound lipids from seeds were established. Iridoids and traces of ecdysterone and flavonoids that co-extracted with the lipids and were characteristic of A. turkestanica were found in phospholipids of vegetative and generative plant organs.

Lipids from seeds and leaves of Solenanthus circinnatus

Lipids from seeds with pericarp and leaves of Solenanthus circinnatus Ledeb. (Boraginaceae) were studied. The contents and class and fatty-acid compositions of neutral lipids, glycolipids, and phospholipids were established. The composition of unsaponified substances of lipids from seeds and leaves was determined. It was found that an insignificant part of S. circinnatus alkaloids was extracted with the lipids.

Multiple Climate Change Factors Interact to Alter Soil Microbial Community Structure in an Old‐Field Ecosystem

Climate change has the potential to alter both the composition and function of a soil’s microbial community, and interactions among climate change factors may alter soil communities in ways that are not possible to predict from experiments based on a single factor. This study evaluated the direct and interactive effects of three climate change factors—elevated CO 2 , altered amounts of precipitation, and elevated air temperature—on soil microbial communities from an old-field climate change experiment being conducted at Oak Ridge, TN. Soil microbial community composition and biomass were determined by phospholipid fatty acid (PLFA) and neutral lipid fatty acid composition. We found that the interactive effects of precipitation and temperature treatments, as well as the interactive effects of precipitation and CO 2 treatments, had significant impacts on microbial community composition. We found that total soil PLFA concentration, a measure of microbial biomass, was greater in the low-precipitation treatments, especially when low precipitation was combined with ambient CO 2 concentrations or ambient temperature. Ordination analysis indicated that temperature was the most significant predictor of shifts in the soil microbial community composition, explaining approximately 12% of the variance in relative abundance of PLFA biomarkers. The elevated-temperature treatment increased the abundance of Firmicutes (low-guanine–cytosine Gram positive) and decreased the abundance of Gram-negative bacteria. Elevated temperature also reduced the abundance of the arbuscular mycorrhizal fungi PLFA biomarker 16:1π5c and saprophytic fungal PLFA biomarker 18:2π6,9. Overall, our data indicate that the interactions among climate change factors alter the composition of soil microbial communities in old-field ecosystems, suggesting potential for changes in microbial community function under predicted future climate conditions.

Lipids and alkaloids from Heliotropium lasiocarpum

Lipids of seeds with pericarp and an admixture of the air-dried aerial part (AP) of Heliotropium lasiocarpum Fisch. et Mey. (Boraginaceae) were studied. The contents and component and fatty-acid compositions of neutral lipids, glycolipids, phospholipids, and strongly bound lipids were established. It was found that part of the alkaloids was extracted together with the lipids from these plant organs. The chromatographic mobility of the heliotrope alkaloids was determined under the lipid separation conditions.

Investigation of γ‐Linolenic Acid and Stearidonic Acid Biosynthesis During a Life Cycle of Borago officinalis L.

AbstractThis study investigated the levels of γ‐linolenic (GLA, 18:3n‐6) and stearidonic acid (SDA, 18:4n‐3) in various parts of the borage plant (Borago officinalis L.) to elucidate Δ6‐desaturase activity. Lipid class and fatty acid (FA) composition during germination of the seeds and FA composition of various borage parts were determined as well as FA compositions of neutral lipids (NL), polar lipids (PL), glycolipids (GL) and monogalactosyl diacylglycerols (MGDG) of borage leaves. When seeds were germinated for 12 days in the dark then exposed to light for 8 h, an overall decrease in oil content was seen with a significant increase in PL from 0.2 to 39.1%. An increase in SDA (from 0.2 to 0.6 g/100 g oil) indicated minor FA synthesis during germination and therefore, Δ6‐desaturase activity with the most marked increase after light exposure. The FA compositions of developing and mature seeds were similar, suggesting oil/FA synthesis takes place at the initial stage of seed development. Among all the borage parts, the leaves had the highest amounts of α‐linolenic acid (ALA, 18:3n‐3) (36.2%), indicating Δ15‐desaturase activity, and SDA (25.2%), indicating Δ6‐desaturase activity. In leaves, the GL and especially, MGDG fractions had the highest amounts of SDA (31.8 and 39.8%, respectively), indicating that Δ6‐desaturase is most active in chloroplasts. Leaves and developing seeds appear to be the major sources of Δ6‐desaturase in borage, associated with different organelles in the different tissues.

Phospholipid characteristics and neutral lipid fatty acid composition related to temperature and nutritional conditions in ecologically important amphipod species from the northern Baltic Sea

Lipid composition of the benthic, stenothermal amphipod Monoporeia affinis collected from constantly cold deep-water (>80m) regions of the northern Baltic Sea was analysed in detail to study phospholipid characteristics, its relation to thermal adaptation as well as potential effects of food quality and seasonal variability. Similar measurements were performed on the littoral, eurythermic amphipod Gammarus spp. Fatty acid (FA) composition of storage lipids of Pontoporeia femorata, a sibling species of M. affinis, was also studied. Interannual and interspecies variability in selected FA was observed both in triacylglycerols (TAG) and phospholipids (PL). Differences in monounsaturated vs. polyunsaturated (MUFA/PUFA) FA combinations of phosphatidyl ethanolamine (PE) diacyl and alkylacyl subgroups were also observed. Seasonal variability in M. affinis was considerably lesser compared to Gammarus spp. A literature synopsis shows that in diacyl PE the share of the FA combination MUFA/PUFA increases with lowering body temperature (40–55% in cold-adapted organisms vs. 5–15% in warm adapted ones), signifying that this characteristic is probably in key position concerning regulation of membrane fluidity in temperature adaptation. According to this feature M. affinis belongs to the group of cold-adapted stenothermic species (Group 1) while eurythermic Gammarus spp. settles in the Group 2 (cold-acclimatized) or 3 (warm-acclimatized/tropical) depending on the status of temperature adaptation. Omnivory and/or periodical food item switching is an important strategy in benthic organisms in high-latitude areas characterised by recurring long poor-nutritional periods. Since many benthic species utilise a time-averaged, integrated food source from phytal and animal matter from various sources the FA composition of TAG of the amphipod species measured here do not exclusively point towards any specific feeding mode or food source. In general, using selected FA as food source markers to assess the diet of field collected more-or-less omnivoric species cannot be considered as an optimal approach. The current study gives more insight to the biochemistry of biological membranes of aquatic crustaceans that is essential in estimation of the capacity of the thermal adaptation/acclimatization of organisms as well as the potential effects of food quality on storage lipids.

Wheat germ oil

In continuation of research on lipids and lipophilic constituents of nontraditional sources of oil-containing raw material [1], we studied lipids and lipophilic components of wheat germ (Triticcum vulgare, Gramineae), which is a multi-ton waste of flour production and typically has a high content of oil [2–4] that is enriched in essential fatty acids. Furthermore, the germ contains vitamins B1, B2, B6, PP, D, and other biologically active compounds [5]. The oil has a beneficial effect on the immune and endocrine systems, stimulates reproductive functions, accelerates wound and burn healing, reduces the cholesterol level in blood, and exhibits antisclerotic and cardioprotective properties [5]. The oil comprises a broad array of biologically active compounds and a variety of pharmacological properties. It is a unique oil for fabricating fatty food products and biologically active additives (BAA), as evidenced by the creation based on it of several BAA [3]. The biological effectiveness of oils is estimated from the degree of balance of their fatty-acid composition [6, 7] and the ratio of -3: -6 acids [8]. Blending of different oils is widely used at present in order to obtain the optimal balance of fatty acids [6, 7]. Therefore, we studied wheat germ oil produced at Karshi flour mill (Uzbekistan) during processing of local wheat varieties. Total neutral lipids (NL) were isolated by benzine extraction (bp 72–85°C) in a Soxhlet apparatus. Bound lipids were isolated from the remaining pulp using the Folch method [9]. Polar lipids were isolated from bound lipids by CC over silica gel. Glycolipids (GL) were eluted by acetone; phospholipids (PL), by MeOH. The yield of NL was 9.30%; GL, 0.70; PL, 0.85 of the air-dried germ mass. The NL composition was established after separation into individual classes using a chromatographic column of silica gel and solvents hexane:Et2O (10:1, 4:1, 7:3, 1:1, and 0:10). Lipids were assigned to individual classes using TLC on silica gel and the aforementioned solvent systems and comparison with model compounds. The content of the classes was estimated gravimetrically. The NL composition was as follows (mass % of extract): hydrocarbons, 0.27; esters of aliphatic and cyclic alcohols with fatty acids, 0.24; triacylglycerides, 78.85; free fatty acids, 18.40; free aliphatic and cyclic alcohols and tocopherols, 2.24. It can be seen that the NL were dominated by TAG. Glycolipids were analyzed using TLC on silica gel and solvents CHCl3:(CH3)2CO:MeOH:H3CCO2H:H2O (65:20:10:10:3). The developers were -naphthol and HClO4 solutions [10]. The GL contained monogalactosyldiglycerides, digalactosyldiglycerides, sterolglycoside esters, and sterolglycosides. The last constituents predominated. The PL contained mainly phosphatidylcholines, phosphatidylethanolamines, and phosphatidylinosites. This was established by two-dimensional TLC on silica gel using solvent systems CHCl3:MeOH:NH4OH (25%) (65:35:5) and CHCl3:MeOH:H3CCO2H:H2O (14:5:1:1). PL were developed using Vaskovsky and Dragendorff’s reagents and ninhydrin solution [9]. The fatty-acid compositions of NL, GL, and PL were determined by GC using a column packed with Reoplex 400 (5%) and Inerton N-AW. Hydrolysis, isolation of fatty acids, and their methylation were performed as before [10]. Table 1 presents the results.

Improvement of a solid phase extraction method for analysis of lipid fractions in muscle foods

The most used method for muscle lipid fractionation into major lipid classes was modified for improving its separation efficiency. Extracted lipids from a masseter muscle of one Iberian pig were separated into neutral lipids (NL), free fatty acids (FFA) and polar lipids (PL) using aminopropyl minicolumns, following the extensively used method of Kaluzny et al. [1] (old method-OM-) and a method based on that, developed by Pinkart et al. [2] with some (modifications modified method–MM). Obtained lipid classes were further analysed by TLC and lipid fractions were identified. TLC evidenced the presence of a certain amount of PL in the NL fraction obtained with the OM. On the other hand, using the MM only an almost undetectable presence of PL was evidenced in the NL fraction. Fatty acid composition of NL, PL and FFA obtained with each method was studied by gas chromatography. Fatty acid profile of NL was strongly influenced by the separation method used. Thus, NL obtained using the OM showed higher amounts of saturated fatty acids (SFA) and polyunsaturated fatty acids (PUFA) and lower of monounsaturated fatty acids (MUFA) than those obtained using the MM. Moreover, NL obtained using the OM showed the presence of fatty alcohols, constituents of phospholipids (PhL) absent or present only in trace amounts in acylglycerols. This profile reflects the coelution of PL in the NL fraction. Fatty acid profile of FFA and PL fractions was also influenced by the solid phase extraction (SPE) method used, but to a lesser extent.

Fatty acid composition and sensory quality of Musculus longissimus and carcass parameters in red deer (Cervus elaphus) grazed on natural pasture or fed a commercial feed mixture

AbstractThe effects of feeding regimen on carcass characteristics, fatty acid composition and sensory quality of Musculus longissimus were studied in 16 male red deer. All animals were farm raised; eight were grazed on pasture and eight were fed a pelleted commercial feed mixture for 10 weeks prior to slaughter. The pellet‐fed deer had a significantly higher dressing percentage than the pasture group. No differences were found in ultimate pH values and muscle glycogen content when comparing the treatment groups. Polar and neutral lipid fatty acid composition of the meat were analysed separately. Meat from pasture‐fed deer showed a high content of the fatty acid 18 : 3 n‐3 in the polar lipid fraction. In the same lipid fraction, the fatty acid 18 : 2 n‐6 was dominant in meat from the pellet fed animals. Similar differences in the neutral lipid fraction were found when comparing fatty acid composition between treatment groups; however, the abundance of these fatty acids was much less. A trained expert panel using a descriptive test assessed the sensory profile of the meat. There was a significant difference between the two treatment groups for the sensory attribute of grassy flavour, with the pellet‐fed animals having less grassy flavour than the animals grazing pasture. It was concluded that further research is needed to explore the effects of various feeding regimens applied to deer on parameters associated with meat lipids, including antioxidants and oxidation products. Copyright © 2003 Society of Chemical Industry

Muscle lipids, vitamins E and A, and lipid oxidation as affected by diet and RN genotype in female and castrated male Hampshire crossbreed pigs

The objectives of this study were to investigate the polar and neutral lipid fatty acid composition, content of retinol, α-tocopherol, γ-tocopherol and level of oxidation of the pig muscle ( M. longissimus dorsi). Female and castrated male Hampshire crossbreeds were produced in two systems. One group was raised indoors with a more polyunsaturated diet and the other raised outdoors with a more saturated diet. The level of polyunsaturated fatty acids in muscle was higher in the indoor females compared with the outdoor females, indoor castrated males and outdoor castrated males. The increased level of polyunsaturated fatty acids in the muscle, which was accompanied by a relatively low content of α-tocopherol, increased the susceptibility to lipid oxidation in the form of MDA (malondialdehyde) in the indoor female pigs. Finally, the level of polyunsaturated fatty acids in the polar lipids was affected by the RN genotype, and this difference was dependent on sex. In conclusion, diet has a major effect on the fatty acid composition and oxidation stability in pork muscle, but additional factors such as sex and RN genotype might also contribute.

Effect of rearing system on muscle lipids of gilts and castrated male pigs

The objective of this study was to investigate the polar and neutral lipid fatty acid composition of pig muscle as influenced by rearing conditions and sex. A total of 120 Hampshire crossbreeds were divided in two groups, one reared free-range in a strip grazing fashion and one reared indoors in a large pen (120 m2). Free-range rearing produced a more unsaturated fatty acid composition (M. biceps femoris) in the neutral lipids, although the effect was small. In the polar lipids the effect of rearing condition was sex dependent. In the muscle of free-range gilts, there was a higher level of C18:2 n-6, compared with indoor gilts, indoor castrates, and free-range castrates. Moreover, muscle of gilts irrespective of rearing condition, had a higher level of the C⩾20 polyunsaturated fatty acids in the polar lipids (16.75 and 14.60, respectively). Thus, we suggest that the difference between castrates and gilts with respect to fatty acid composition in the polar lipids, might be affected by rearing condition.

Fatty acid composition of M. longissimus lumborum, ultimate muscle pH values and carcass parameters in reindeer (Rangifer tarandus tarandus L) grazed on natural pasture or fed a commercial feed mixture

The effects of feeding regimen on the fatty acid composition of M. longissimus, ultimate pH values in three muscles (Mm. longissimus, triceps brachii and biceps femoris) and carcass quality were studied in15 reindeer bulls. Nine animals came from natural pasture and six had been fed a pelleted commercial feed mixture for two months prior to slaughter. The pellet fed reindeer had significantly better carcass grading scores (EUROP conformation), higher trim fat content, more intramuscular fat and lower ultimate pH values in all three muscles than the group from pasture. The polar and neutral lipid fatty acid composition of the meat was analysed separately. Meat from pasture fed reindeer showed a high content of the fatty acid 18:3 n-3 in the polar lipid fraction. In the same lipid fraction, the fatty acid 18:2 n-6 was dominant in meat from the pellet fed animals. Similar differences in the neutral lipid fraction were found when comparing fatty acid composition between treatment groups, however the abundance of these fatty acids was much less. The present results confirm previous findings that reindeer fed typical pelleted commercial feed mixtures generally have an improved nutritional status.

A comparative study of the composition of lipids associated with starch granules from various botanical sources

Lipids from highly purified wheat, rice, corn, fababean, lentil, potato and cassava starches were extracted by acid hydrolysis and by selective solvent extraction with chloroform-methanol 2:1 v/v [CM] at ambient temperature, followed by n-propanol-water 3:1 v/v [PW] at 90–100°C. The acid hydrolyzed extracts which represented the total starch lipid [TSL] content ranged from 0.1% (potato) to 0·8% (corn). The combined action of CM and PW resulted in almost complete removal of starch lipids (>98·6%) from most of the starches, the exception being wheat, where the solvent extraction efficiency (% TSL) was 96·3%. The free lipids in the CM extracts (% TSL) ranged from 5·0% (corn) to 62% (fababean), whereas the free and bound lipids in the PW extracts ranged (% TSL) from 44·2% (potato) to 94·8% (corn). Neutral lipids (NL) formed the major lipid class in the CM extracts of all starches, while in PW extracts these were NL in corn and cassava, NL and phospholipids (PL) in potato, and PL in wheat, rice and fababean. There was a great variation among the starches with respect to the major components of the lipid classes in both CM and PW extracts. Monoacyl lipids were most abundant in cereal starches (>78% TSL). The fatty acid composition of NL, GL and PL in CM and PW extracts was determined.

The development of pulmonary surfactant lipids in a neonatal marsupial and the rat

The composition of pulmonary surfactant during development was compared in a marsupial, the tammar wallaby, and the rat. For both species phospholipid fatty acid and neutral lipid fatty acid composition is similar, and phosphatidylcholine was the principal phospholipid at each age group. The relative amount of each phospholipid class significantly changed with time in both species but the extent of these changes did not vary between species. The neutral lipid component of surfactant varied significantly between the marsupial and eutherian, with higher levels of free cholesterol observed in the former. Overall the lipid composition of pulmonary surfactant in the developing wallaby is similar to that seen in eutherians with the exception being the level of free cholesterol.

Ovarian neutral lipid fatty acid composition varies with state of ovarian growth in landlocked Atlantic salmon

The ovarian neutral lipid fatty acid composition was determined for 22 landlocked Atlantic salmon with gonadosomatic index ranging from 0.75 to 13.6. In fish with gonadosomatic index over 1.3, the proportions of 16:1 and 18:1 increased, while those of 20:5 (n – 3) and 22:6 (n – 3) decreased with increasing gonadosomatic index. The proportion of the other major neutral lipid fatty acid, 16:0, did not vary with gonadosomatic index. Analysis of selected samples did not reveal any relationship between gonadosomatic index and the proportions of the major phospholipid fatty acids, 22:6 (n – 3), 16:0, and 18:1.

Milk Fat Globule Membrane Composition and Dietary Change: Supplements of Coconut Oil Fed in Two Physical Forms

Milk fat globule membrane composition was compared in two diets, E and F. Both contained coconut oil supplement emulsified with casein, but in diet F the supplement had been treated with formaldehyde. More membrane was secreted in diet E, and it contained a greater proportion of neutral lipid and a lower proportion of protein than diet F. No difference in neutral lipid fatty acid composition of membrane was observed between diets E and F. The amounts of coconut oil fatty acids in membrane neutral lipids were higher in diets E and F than in a ration containing no coconut oil. Individual phospholipids were unaffected by diet, and no incorporation of the supplemented lipid into membrane polar lipids occurred. Proportions of major membrane proteins changed as shown by sodium dodecyl sulphate-polyacrylamide gel electrophoresis.