Comprehensive and quantitative profiling of lipid species in human milk,cow milk and a phospholipid‐enriched milk formula by GC and MS/MSALL

Here we present a workflow for in‐depth analysis of milk lipids that combines gas chromatography (GC) for fatty acid (FA) profiling and a shotgun lipidomics routine termed MS/MS^ALL for structural characterization of molecular lipid species. To evaluate the performance of the workflow we performed a comparative lipid analysis of human milk, cow milk, and Lacprodan^® PL‐20, a phospholipid‐enriched milk protein concentrate for infant formula. The GC analysis showed that human milk and Lacprodan have a similar FA profile with higher levels of unsaturated FAs as compared to cow milk. In‐depth lipidomic analysis by MS/MS^ALL revealed that each type of milk sample comprised distinct composition of molecular lipid species. Lipid class composition showed that the human and cow milk contain a higher proportion of triacylglycerols (TAGs) as compared to Lacprodan. Notably, the MS/MS^ALL analysis demonstrated that the similar FA profile of human milk and Lacprodan determined by GC analysis is attributed to the composition of individual TAG species in human milk and glycerophospholipid species in Lacprodan. Moreover, the analysis of TAG molecules in Lacprodan and cow milk showed a high proportion of short‐chain FAs that could not be monitored by GC analysis. The results presented here show that complementary GC and MS/MS^ALL analysis is a powerful approach for characterization of molecular lipid species in milk and milk products. Practical applications : Milk lipid analysis is routinely performed using gas chromatography. This method reports the total fatty acid composition of all milk lipids, but provides no structural or quantitative information about individual lipid molecules in milk or milk products. Here we present a workflow that integrates gas chromatography for fatty acid profiling and a shotgun lipidomics routine termed MS/MS^ALL for structural analysis and quantification of molecular lipid species. We demonstrate the efficacy of this complementary workflow by a comparative analysis of molecular lipid species in human milk, cow milk, and a milk‐based supplement used for infant formula. A workflow for milk lipid analysis based on combined gas chromatography and high‐resolution shotgun lipidomics. In‐depth structural characterization and quantification of molecular lipid species in milk and milk products.     

Potential of animal nutrition to decrease the saturated fatty acids in meat and milk

Medical authorities recommend that energy intake from saturated fatty acids (SFA) should not exceed 10% of total energy intake. Milk and meat, because of their relatively high SFA concentration and level of consumption, make a large contribution to human SFA consumption. Strategies to decrease the SFA content in meat and milk include inclusion of forage in the ration of ruminants and supplementation of dietary intake of ruminants and monogastrics with unsaturated fatty acid‐rich oilseeds, fish oil or marine algae. The influences of these manipulations will be illustrated and the likely future trends in the SFA content of meat and milk will be suggested.     

Unbound DHA causes a high blank value in β‐oxidation assay: a concern for in vitro studies

The information on binding capacity of different fatty acids (FAs) to albumin is incomplete, however, in the majority of in vitro experiments, FAs and albumin were simply mixed and their affinity believed to be complete. In this study, seven [1‐¹⁴C] FAs were mixed with albumin and assayed for β‐oxidation in rat liver homogenates. In the process of identifying the radioactive background of control assay by LCMS/MS, the results indicated different binding capacity of FAs to albumin. The percentage of unbound FAs recovered in clarified acidic solution was lower than 2% with 16:0 and 18:1n‐9, nearly 5% with EPA, 7% with 18:2n‐6, 18:3n‐3 and 20:4n‐6, and surprisingly high to 41% with DHA. Various FA/albumin molar ratios as well as different types of albumin only marginally affected these data. Thus, the big mass of unbound free DHA led to a high blank value, which is 60 times higher than the real value in the procedure of β‐oxidation measurement in vitro. In the design of future FA research in vitro, the binding capacity of FA to albumin or other proteins must be considered, especially for DHA research.     

Effect of Feeding a Low Level of Encapsulated Fish Oil to Dairy Goats on Milk Yield,Composition, and Fatty Acid Profile

Contradictory results have been found in the response of dairy goats to the supplementation of fish oil in their diet to improve the n-3 polyunsaturated fatty acids (PUFA) in milk. The responses to the inclusion of fish oil in the diet of ruminants either induced milk fat depression, increased milk fat content, and/or negatively impacted milk yield. The objective of this study was to determine whether including a low dose of encapsulated fish oil in the diet of goats can modify yield, milk composition, and the fatty acid (FA) profile of milk. Ten Alpine goats were divided into two homogeneous subgroups and assigned to either the control or experimental diet. The control animals received the basal diet without supplementation of fish oil, whereas the experimental group was given the same basal diet supplemented with encapsulated fish oil (1.14 g /kg of concentrate) for 56 days. Milk samples were analyzed for chemical composition and FA profile. The inclusion of encapsulated fish oil in the goat diet did not affect the yield and composition of goat milk. The effect of diet was not significant on the FA profile of goat milk, except that 20:0 was lower (P < 0.05) in the milk of goats that received fish oil. The low dose of encapsulated fish oil supplement used in this study did not impact (P > 0.05) the PUFA content of goat milk or milk composition and yield; however, the atherogenicity index (AI), which is beneficial to heart health, was lower (P < 0.05) in the milk of goats that received fish oil as a supplement in their diet compared to the control.     

Effect of fish oil on the fatty acid composition of human milk and maternal and infant erythrocytes

To examine the effect of fish oil supplementation on the fatty acid (FA) composition of human milk and maternal and infant erythrocytes, five lactating women were supplemented with 6 g of fish oil daily for 21d. Usual maternal diets contained 1,147 mg of total n−3 FA, with 120 mg from very long-chain (>C₁₈) n−3 FA. Supplementation increased dietary levels to 3,092 mg of total n−3 FA and 2,006 mg of very long-chain n−3 FA. Milk samples were collected daily, prior to fish oil ingestion, and at 4-h intervals on days 1, 7, 14 and 21. Milk n−3 FA content increased within 8 h and reached steady state levels within one week. The n−6 fatty acid content decreased. Erythrocyte eicosapentaenoic acid content increased from 0.24% to 1.4% (P<0.01) in mothers and from 0.11% to 0.70% (P<0.05) in infants. Docosapentaenoic acid increased from 1.4% to 2.2% (P<0.05) in mothers and from 0.30% to 0.78% (P<0.01) in infants. There was no significant change in docosahexaenoic acid or n−6 fatty acid content. Maternal platelet aggregation responses were variable. No differences in milk or plasma tocopherol levels were noted. Based on a paper presented at the Symposium on Milk Lipids held at the AOCS Annual Meeting, Baltimore, MD, April 1990.     

Milk Phospholipids Enhance Lymphatic Absorption of Dietary Sphingomyelin in Lymph-Cannulated Rats

Supplementation with sphingomyelin has been reported to have beneficial effects on disease prevention and health maintenance. However, compared with glycerolipids, intact sphingomyelin and ceramides are poorly absorbed. Therefore, if the bioavailability of dietary sphingomyelin is increased, then the dose administered can be reduced. This study was designed to identify molecular species of ceramide in rat lymph after the ingestion of milk sphingomyelin, and to compare the effect of purified sphingomyelin with milk phospholipids concentrate (MPL, 185 mg sphingomyelin/g) on lymphatic absorption of milk sphingomyelin. Lymph was collected hourly for 6 h from lymph‐cannulated rats (n = 8/group) after the administration of a control emulsion (triolein, bovine serum albumin, and sodium taurocholate), a sphingomyelin emulsion (control + purified sphingomyelin), or a MPL emulsion (control + MPL). Molecular species of ceramide in lymph were analyzed using high‐performance liquid chromatography‐tandem mass spectrometry (HPLC–MS/MS). Molecular species of ceramide, containing not only d18:1, but also d17:1 and d16:1 sphingosine with 16:0, 22:0, 23:0, and 24:0 fatty acids (specific to milk sphingomyelin), were increased in rat lymph after the administration of milk sphingomyelin. Their molecular species were similar to those of dietary milk sphingomyelin. Recovery of ceramide moieties from dietary sphingomyelin was 1.28‐ to 1.80‐fold significantly higher in the MPL group than in the sphingomyelin group. Our results demonstrated that dietary sphingomyelin from milk was transported to lymph as molecular species of ceramide hydrolyzed from milk sphingomyelin and co‐ingestion of sphingomyelin with glycerophospholipids enhanced the bioavailability of dietary sphingomyelin.     

“Click Chemistry” for the Simple Determination of Fatty‐Acid Uptake and Degradation: Revising the Role of Fatty‐Acid Transporters

Fatty acids (FAs) have numerous functions in all living organisms, ranging from structural roles and energy production to the biosynthesis of secondary metabolites. Because of the high energy content of exogenous FAs, their acquisition is central of metabolism, and several biological systems are known, although their precise roles are not yet entirely clear. We investigated the roles of FadD (CoA ligase) and FadL (FA transporter) in different bacterial strains by using an improved version of click‐chemistry‐assisted labelling of azido‐FAs. The high sensitivity of this method allows a direct and precise assessment of FA metabolism, and is thus far better suited than growth experiments. Our results show that although FA activation is indeed essential for FA degradation, their transport can be independent of transporters like FadL.     

Modifying milk fat composition of dairy cows to enhance fatty acids beneficial to human health

There is increased consumer awareness that foods contain microcomponents that may have beneficial effects on health maintenance and disease prevention. In milk fat these functional food components include EPA, DHA, and CLA. The opportunity to enhance the content of these FA in milk has improved as a result of recent advances that have better defined the interrelationships between rumen fermentation, lipid metabolism, and milk fat synthesis. Dietary lipids undergo extensive hydrolysis and biohydrogenation in the rumen. Milk fat is predominantly TG, and de novo FA synthesis and the uptake of circulating FA contribute nearly equal amounts (molar basis) to the FA in milk fat. Transfer of dietary EPA and DHA to milk fat is very low (<4%); this is, to a large extent, related to their extensive biohydrogenation in the rumen, and also partly due to the fact that they are not transported in the plasma lipid fractions that serve as major mammary sources of FA uptake (TG and nonesterified FA). Milk contains over 20 isomers of CLA but the predominant one is cis-9,trans-11 (75–90% of total CLA). Biomedical studies with animal models have shown that this isomer has anticarcinogenic and anti-atherogenic activities. cis-9,trans-11-CLA is produced as an intermediate in the rumen biohydrogenation of linoleic acid but not of linolenic acid. However, it is only a transient intermediate, and the major source of milk fat CLA is from endogenous synthesis. Vaccenic acid, produced as a rumen biohydrogenation intermediate from both linoleic acid and linolenic acid, is the substrate, and Δ9-desaturase in the mammary gland and other tissues catalyzes the reaction. Diet can markedly affect milk fat CLA content, and there are also substantial differences among individual cows. Thus, strategies to enhance milk fat CLA involve increasing rumen outflow of vaccenic acid and increasing Δ9-desaturase activity, and through these, several-fold increases in the content of CLA in milk fat can be routinely achieved. Overall, concentrations of CLA, and to a lesser extent EPA and DHA, can be significantly enhanced through the use of diet formulation and nutritional management of dairy cows.     

Prediction of the goat milk fatty acids by near infrared reflectance spectroscopy

Near infrared reflectance spectroscopy (NIRS) was used to predict the goat milk fatty acid (FA) profile. The ability of cow milk broad‐based calibration equations to predict the goat milk FA profile was assessed. Three hundred twenty‐eight samples in the calibration set and 108 in the validation set were analyzed. We showed that the bias and unexplained error were significant for most of the FA despite an adequate standardized Mahalanobis distance (index to establish the boundaries of a population of samples) which allowed us to test the ability of bovine models to predict goat milk FA profiles. To better predict the goat milk FA composition, a specific goat model was investigated. The cross‐validation coefficient of determination (R²CV; proportion of variance explained by the model in cross‐validation) and residual predictive deviation (RPD; index which allows to standardize the standard error of prediction (SEP)) were >0.90 and 3, for saturated, monounsaturated, and unsaturated FA, total trans FA, isomer cis9trans11 of CLA, cis9‐, trans10‐, and trans11‐C18:1, respectively. Monitoring of the equation performance of milk FA included the calculation of the bias and unexplained error. Practical applications: In this work, we evaluated the ability of NIRS to predict FA composition of goat milk and tested the ability of using broad‐based cow milk calibration equations to monitor an independent set of goat milk samples. We tested the hypothesis that the calibration equations obtained for FA from cow milk could be applied on goat milk. As the spectra of goat milk are similar to those of cow milk when they are measured by the standardized Mahalanobis distance (index to establish the boundaries of a population of samples), we can accept the hypothesis. It will be possible to use the existing calibration equations for predicting FA profile on spectra of milk of a different specie. However, the rejection of the hypothesis would put in doubt the use of Mahalanobis distance as the unique index for testing the performance of calibration equations on different milk populations for predicting FA.     

Introduction to the symposium on milk lipids

Milk lipids, often referred to as “milk fat,” have been of interest to man for centuries. Milk fat is a major component of bovine milk and most dairy foods and has the highest economic value of any of the milk constituents. In 1970, over 4 billion pounds of milk fat were produced by 12 million cows in the U.S. Practically all this fat was used in food products and provided ca. 16% of the total visible and invisible fat consumed by Americans. Although milk fat has been the subject of many investigations in the past, there is continuing interest in its complex composition and its chemical, physical and nutritional properties. The purpose of this symposium is to review contemporary knowledge of milk lipids and to focus attention on recent developments of interest to individuals associated with the field of edible fats and oils. One of eight papers presented in the symposium “Milk Lipids,” AOCS Meeting, Ottawa, September 1972.     

The influence of dietary rumen‐protected linoleic acid on milk fat composition,spreadability of butter and energy balance in dairy cows

The aim of this study was to determine the effects of a diet supplemented with rumenprotected linoleic acids (C18:2) on the composition of milk fat and the energy balance of dairy cattle during the first 15 wk of lactation. The 32 Holstein‐Friesian cows were allotted in two treatment groups; in the experimental group one‐third of the starch (relative to the control group) was substituted with protected fat on an energy basis. Milk samples from all cows were collected weekly from week 2 to 15 postpartum (p.p.). To analyze the milk fat composition milk samples from 16 cows in each group were collected from week 6 and 7 as well as from week 13 and 14 p.p. and were mixed together, respectively. Triglyceride analysis demonstrated an extensive use of depot fat in both cow groups at the beginning of the lactation period. However, calculated energy balance, triglyceride composition and back fat thickness showed that the usual deficit of energy intake in early lactation was significantly shortened in the experimental group by three weeks. In comparison with the control group the content of the saturated fatty acids (FAs) C12, C14 and C16 in the experimental group decreased by 17.3% at 6 to 7 wk and by 19.2% at 13 to 14 wk. The stearic acid content of milk fat was increased by 25.9% at 6 to 7 wk and by 27.7% at 13 to 14 wk in the experimental group. The content of cis Δ9 oleic acid was increased by 21.6% at 6 to 7 and by 30.3% at 13 to 14 wk, while the C18:2 FA content was doubled as compared with the control group. Thus besides the increase of the trans‐C18:1 FA (TFA) content the nutritional value of fats could be improved using the experimental fat supplement. The TFA content still remained within the range of variation of natural milk fats. Additionally the experimental fat intake led to a number of desired effects; an increase in the content of conjugated linoleic acids (cis Δ9, transΔ11) by 55.9% (6 to 7 wk) and by 97.1% (13 to 14 wk p.p.), respectively, and a decrease in the cholesterol level. Further, the butyric acid content increased relatively by more than 20%. The addition of this fat resulted simultaneously in a changed triglyceride composition with increased C50, C52 and C54 contents. Thus a markedly improved spreadability of the resulting butter might be expected.     

Die Zusammensetzung der Triglyceride von Kuhmilch und Humanmilch

Triglyceride Composition of Bovine and Human Milk The triglyceride composition in the fat portion of bovine milk (winter and summer) and mature human milk was calculated from the HPLC partition number and from the carbon number and fatty acid pattern in the HPLC fractions. The triglycerides identified (122 in bovine milk, 94 in human milk) and their contents in the HPLC fractions are tabulated.     

Synthesis and physical properties of isostearic acids and their esters

Saturated branched‐chain fatty acids (sbc‐FAs) are found as minor constituents in several natural fats and oils. Sbc‐FAs are of interest since they have lower melting points than their linear counterparts and exhibit good oxidative stability; properties that make them ideally suited in a number of applications. We (and others) have previously synthesized sbc‐FAs by clay‐ or zeolite‐catalyzed isomerization of unsaturated linear‐chain fatty acids (ulc‐FAs) to unsaturated branched‐chain fatty acids (ubc‐FAs) that were subsequently hydrogenated to the desired sbc‐FAs. These acid‐catalyzed isomerization reactions, however, proceed in moderate conversion and selectivity. Recently, our group found that H‐Ferrierite zeolite catalyst isomerized ulc‐FAs to their branched‐chain counterparts in high conversion (>95%) and selectivity (85%). This paper reports the use of this type of catalyst for the preparation of a series of sbc‐FAs and their ester derivatives. Selected physical properties of these branched acids and esters such as cloud point (CP) and pour point (PP), cold filter plugging point (CFPP), viscosity index (VI), thermo‐oxidation stability, iodine value, and lubricity are also reported.     

Combining Results of Two GC Separations Partly Achieves Determination of All <Emphasis Type="Italic">cis</Emphasis> and <Emphasis Type="Italic">trans</Emphasis> 16:1, 18:1, 18:2 and 18:3 Except CLA Isomers of Milk Fat as Demonstrated Using Ag-Ion SPE Fractionation

Milk fat is a complex mixture of geometric and positional isomers of monounsaturated and polyunsaturated, including short-, long- and branch-chain fatty acids (FAs). There has been partial success to resolve this mixture of FAs using different GC temperature programs, or a combination of GC isothermal and temperature programs. To overcome the problem associated with overlapping isomers prior silver-ion separation was recommended. However, this procedure is time consuming and not practical for routine analysis. In addition, previous methods focused mainly on the trans and cis isomers of 18:1. The present method takes advantage of differences in the relative elution times between different types of FAs. The method involved analyzing each milk fat using the same highly polar 100-m capillary column and GC instrument, and conducting two separations using temperature programs that plateau at 175 and 150 °C. The relative shift among the geometric and positional isomers at these two temperature settings was enough to permit identification of most of the trans and cis 16:1, 18:1 and 20:1, the c/t-18:2 and the c/c/t-18:3 isomers found in milk fat. The identity of these FAs was confirmed by prior separation of the total fatty acid methyl esters (FAMEs) of milk fat using Ag⁺-SPE columns, and comparing the fractions to the total milk fat. The Ag⁺-SPE technique was modified to obtain pure saturated, trans- and cis-monounsaturated and diunsaturated FAMEs. By combining the results from these two separate GC analyses, knowing the elution order, it was possible to determine most of the geometric and positional isomers of 16:1, 18:1, 20:1, 18:2 and 18:3 without a prior silver-ion separation. Only few minor FAs could not be resolved, notable the conjugated linoleic acid isomers that still required the complimentary Ag⁺-HPLC separation. The two GC temperature programs have been successfully used to routinely analyze most FA isomers in total milk and beef fats in about 200 min without the use of prior silver-ion separations.     

White Bass (<Emphasis Type="Italic">Morone chrysops</Emphasis>) Preferentially Retain n-3 PUFA in Ova When Fed Prepared Diets with Varying FA Content

We evaluated the fatty acid (FA) composition of broodstock white bass ova fed one of six commercial diets with increasing polyunsaturated FA content (n‐6/n‐3 ratio; 0.36, 0.39, 0.46, 0.83, 1.07, 1.12) eight weeks prior to sampling. Fatty acid profiles of ova from brooders fed each of the six diets were significantly altered according to canonical discriminant analysis. Ova FA profiles resulting from the 0.39 diet separated those from the 0.36 diet based on lower 18:2n‐6 (LNA) and higher 20:1n‐9 concentrations from the 0.36 diet. Ova profiles were further separated based on lower concentrations of 22:5n‐3 (DPA) from the 0.46 diet, lower concentrations of 20:5n‐3 (EPA) in the 1.12 and 0.83 diets, and lower concentrations of 22:6n‐3 (DHA) in all other diets relative to the 0.46 diet. Changes in ova FA profile at four and eight weeks were consistent with dietary intake with an approximate 2% increase in any given FA class with increasing time on individual diet. There was no correlation between dietary ARA concentrations (0.7–1.1 mol%), or dietary EPA/ARA ratios (7–15), and the concentrations (1.4–1.7 mol%) or ratios (3.3–4.4) found in the ova by diet. Our results suggest that white bass females have the ability to preferentially incorporate n‐3 PUFA, particularly DHA, suggesting mobilization of this FA from other tissues for ova deposition or preferential dietary incorporation of PUFA into ova. These results will add to the limited FA information available in white bass and enable nutritionists to formulate broodstock diets that maximize reproductive potential in this species.     

A new approach for the classification of coal fly ashes based on their origin,composition, properties,and behaviour

The present work introduces and evaluates a new approach for the classification system of coal fly ashes (FAs) based on their origin, phase-mineral and chemical composition, properties, and behaviour. The detailed data for 41 FAs produced from various feed coals at 37 coal-fired thermo-electric power stations (TPSs) in Spain, Bulgaria, The Netherlands, Italy, Turkey, and Greece were used for that purpose. The chemical FA classification system was organized according to the contents, common geochemical associations, and significant positive or negative correlations of ash-forming elements in FAs using three end members, namely (1) sum of Si, Al, K, Ti and P oxides; (2) sum of Ca, Mg, S, Na and Mn oxides; and (3) Fe oxide. This approach divided four chemical FA types (Sialic, Calsialic, Ferrisialic, and Ferricalsialic) with three dominant tendencies (high acid, medium acid, and low acid). The most important phase-mineral FA classification system was organized according to the contents, associations, correlations, properties, and behaviours of species in FAs using also three end members, namely: (1) glass; (2) quartz + mullite; and (3) other minerals. This approach divided four phase-mineral FA types (Pozzolanic, Inert, Active, and Mixed) with three dominant tendencies (high pozzolanic, medium pozzolanic, and low pozzolanic). The specified chemical and phase-mineral FA types and subtypes were characterized and the relationships and distinctions between them were also described. It was found that characteristics such as (1) feed coal and combustion technology used in TPS; (2) water–soluble, magnetic and heavy fractions, pH, fluid ash-fusion temperature, detrital/authigenic index, and BET specific surface area of FAs; and especially (3) content, modes of occurrence, and distribution of glass, quartz, mullite, lime-portlandite, periclase-brucite, Ca sulphates, Ca and Ca–Mg silicates, magnetite-hematite, and char types in FAs; give the most valuable information for the determination of the potential utilization directions and environmental concerns of FAs.     

Application of Fatty Acids for Chemotaxonomy of Reef-Building Corals

Sixteen scleractinian species of six coral families (Acroporidae, Pocilloporidae, Poritidae, Faviidae, Pectiniidae, and Fungiidae) from Vietnam were analyzed for fatty acid (FA) composition. Except for the Poritidae species, total lipids of the corals had the same set of FAs, about 50% of them being unsaturated acids. Some coral families had high levels of characteristic FAs: 20:3(n-6), 20:4(n-3), and 22:6(n-3) in Pocilloporidae; 18:1(n-9) and 22:6(n-3) in Poritidae; and 18:3(n-6) and 22:5(n-3) in Faviidae. For the first time in hexacorals, unsaturated C₂₄ FAs (24:1(n-9), 24:2(n-6), 24:2(5,9), 24:3(5,9,17), and 24:4(n-3)) were discovered in the Poritidae species. The highest level of 18:1(n-7), odd-chain and branched FAs (7.5% in total) was detected in Sandalolitha robusta. The data obtained on the contents of ten principal C₁₈–C₂₂ polyunsaturated FAs (PUFAs) for the 16 specimens were combined with data on the 19 reef-building coral specimens investigated previously and subjected to multidimensional scale analysis (MSA). The representative coral families (Acroporidae, Pocilloporidae, Poritidae, Faviidae, Dendrophylliidae, and Milleporidae) were separated by MSA according to the composition of their principal PUFAs. Therefore, PUFAs may serve as chemotaxonomic markers for reef-building corals at the family level. Family-specific compositions of coral zooxanthellae characterized by different PUFA profiles, which affect the PUFA content of whole coral colonies, were supposed to be the probable cause of the discovered chemotaxonomic distinctions between reef-building corals.     

Improved synthesis and characterization of saturated branched‐chain fatty acid isomers

The development of viable technologies for producing green products from renewable fats and oils is highly desirable since such materials can serve as replacements for non‐renewable and poorly biodegradable petroleum‐based products. Mixtures of saturated branched‐chain fatty acid isomers (sbc‐FAs), commonly referred to as isostearic acid, are important intermediates for the production of biodegradable lubricants, cosmetics, emollients, and hydraulic fluids. Present methods for producing sbc‐FAs, however, often give low yields of sbc‐FAs or sbc‐FA preparations with a high content of dimer acid fatty acid co‐products. This study reports an improved route to synthesizing sbc‐FAs from monounsaturated fatty acids using a modified H‐Ferrierite zeolite catalyst in conjunction with small amounts of triphenylphosphine additive. The yields of sbc‐FAs (up to 80 wt%) and co‐products (up to15 wt%) were determined using a modification of a previously reported GC method. A more detailed analysis of the distribution of sbc‐FA isomers in the products was made by the combined use of GC × GC‐TOF‐MS. Additionally, it was found that the H‐Ferrierite zeolite catalyst was recyclable and reusable up to 10 times without significant loss of activity and selectivity for sbc‐FAs.     

Fatty Acid Composition of Seeds From Wild and Cultivated Ginseng (Panax ginseng Meyer): Occurrence of a High Level of Petroselinic Acid

The lipid content and fatty acid (FA) composition of seeds from the Asian ginseng Panax ginseng growing naturally in taiga forests of the Russian Far East and seeds from cultivated ginseng were studied in this work. The total lipid content of seeds from both wild and cultivated plants was 9–12 % of fresh weight. FA were analyzed as isopropyl esters on a polar capillary column BD‐225, which allows good separation of petroselinic and oleic acids. The structure of FAs was confirmed using GC–MS of fatty acid methyl ester (FAME) and 4,4‐dimethyloxazoline derivatives. In all the seed samples, the major FA was petroselinic acid 18:1(n‐12) which comprised more than 60 %; the contents of oleic and linoleic acids were lower (15–17 and 15–16 %, respectively). Earlier, a higher level (>80 %) of oleic acid had been reported for ginseng seeds. This discrepancy can be explained by an insufficient separation of these acids on standard columns used for GC of FAME. In general, seeds of wild and cultivated ginseng are very similar in lipid content and FA composition.     

Fatty Acid,Lipid Class,and Phospholipid Molecular Species Composition of the Soft Coral Xenia sp. (Nha Trang Bay,the South China Sea,Vietnam)

The soft corals of the genus Xenia are common for Indo‐Pacific reef ecosystems. Lipid class, fatty acid (FA), phospho‐ and phosphonolipid molecular species compositions were identified for the first time in the soft coral Xenia sp. from Vietnam. Total lipids consisted predominantly of waxes, monoalkyl diacylglycerols, triacylglycerols, sterols, and polar lipids (21.4, 7.7, 14.2, 10.5, and 36.7 %, respectively). Sesquiterpene alcohol, valerenenol, was found. Acids 16:0, 18:3n‐6, 20:4n‐6, and 20:5n‐3 dominated in total FA. The markers of zooxanthellae (18:4n‐3 and 18:5n‐3) and octocorals (24:5n‐6 and 24:6n‐3) were detected. Acids 18:5n‐3, 20:4n‐6, 22:4n‐6, and 24:5n‐6 concentrated in FA of polar lipids, whereas 14:0, 16:0, 16:1n‐7, 18:2n‐6, and 18:3n‐6 were the major FA of neutral lipids. ChoGpl, EtnGpl, SerGpl, CAEP, PtdIns, and lyso ChoGpl constituted 39.5, 20.8, 20.5, 9.7, 4.3, and 5.3 %, respectively, of the sum of phospho‐ and phosphonolipids. Thirty‐two molecular species of phospholipids and ceramide aminoethylphosphonate (CAEP) were determined by high resolution tandem mass spectrometry. Lyso 18:0e PakCho (4.1 %), 18:0e/20:4 PakCho (20.5 %), 18:1e/20:4 PlsEtn (18.0 %), 18:0e/24:5 PakSer (14.0 %), and 16:0 CAEP (9.6 %) were the major molecular species. EtnGpl and PtdIns mainly consisted of alkenyl acyl and diacyl forms, respectively. Alkyl acyl forms predominated in ChoGpl and SerGpl. Acid 24:5n‐6 was a principal FA in SerGpl, whereas 20:4n‐6 was more abundant in ChoGpl and EtnGpl. PtdIns contained various C_20–24 PUFA. In the context of chemotaxonomy of corals, Xenia sp. has the lipid composition typical for soft corals and the FA profile similar to that of alcyonarians with the high level of 18:3n‐6.