Microbial Conversion of Vegetable Oil to Rare Unsaturated Fatty Acids and Fatty Alcohols by an <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis> Isolate

We isolated two new microorganisms capable of converting vegetable oil to several rare unsaturated fatty acids and rare unsaturated fatty alcohols from a soil sample. The strains were identified as belonging to the same genus and species, Aeromonas hydrophila. The rare unsaturated fatty acids and rare unsaturated fatty alcohols were accumulated as a wax ester form by the strains. Compared to other strains, the A. hydrophila isolates effectively decreased fatty acid chain lengths and converted rapeseed oil, which is rich in 9-C18:1 fatty acid, into rare fatty acids, such as 7-C16:1 fatty acid and 5-C14:1 fatty acid. Furthermore, the A. hydrophila isolates converted the resulting fatty acids to rare unsaturated fatty alcohols, such as 7-C16:1 fatty alcohol and 5-C14:1 fatty alcohol. The isolates also converted safflower oil, which is rich in 9,12-C18:2 fatty acid, to 7,10-C16:2 fatty acid, 5,8-C14:2 fatty acid, 9,12-C18:2 fatty alcohol, 7,10-C16:2 fatty alcohol, and 5,8-C14:2 fatty alcohol. 7,10,13-C16:3 fatty acid, 9,12,15-C18:3 fatty alcohol, and 7,10,13-C16:3 fatty alcohol were also converted from linseed oil, which is rich in 9,12,15-C18:3 fatty acid, by the A. hydrophila isolates. These fatty acids and fatty alcohols are rarely found in natural oils. Since decreasing fatty acid carbon chain lengths from the carboxyl end and reducing unsaturated fatty acids to unsaturated fatty alcohols are both difficult reactions to accomplish by chemical means, we suggest that these A. hydrophila isolates may facilitate introduction of new bioprocess for producing rare unsaturated fatty acids and rare unsaturated fatty alcohols, especially fatty alcohols harboring more than two double bonds.     

Synthesis and Surface Active Properties of Sulfonated Acrylate Esters Based on Al‐Cedre Oil

Sulfonated acrylate esters have been synthesized by using renewable raw materials such as fatty alcohols of Al‐Ceder oil. Mixed fatty acids were isolated from Al‐Ceder oil by hydrolysis; both saturated and unsaturated fatty acids were isolated from the mixed fatty acids. The methyl esters of mixed fatty acid, saturated and unsaturated acids of Al‐Cedre oil were subjected to reduction with (LiAlH4) to give the corresponding fatty alcohols. The products of the reduction process were saponified and the hydroxyl values were estimated to further confirm the reduction occurrence. The acrylate esters were synthesized by esterification of acrylic acid with fatty alcohols of C_16:0, C_18:0, C_18:1, and C_18:2 mixed saturated, mixed unsaturated and mixed fatty acids of Al‐Cedre oil, respectively. This esterification was followed by addition of NaHSO₃ to form bisulfite adducts. The structures of the prepared surfactants were characterized by IR and ¹HNMR spectroscopy. A series of useful surface parameters, stability towards acids and base hydrolysis and calcium stability have been determined.     

Fatty acid profile in baby food products

The fatty acid composition in the lipid phase of 64 commercially available baby food products, of two different batches each, was analyzed. They comprised vegetable products for babies of five, eight, and twelve months and fruit and cereal products of three different brands. The comparison of the composition of the saturated (C18:0, C16:0, C14:0, C12:0, C10:0), the unsaturated monoenoic (C18:1n9 and C16:1n7) and the polyenoic (C18:2n6 and C18:3n3) fatty acids was determined by gas chromatography. All analyzed baby food products provided well‐balanced amounts of saturated fatty acids on the one hand (saturated fatty acids (SFA) 31—37% of total fatty acids) and unsaturated fatty acids on the other hand (monounsaturated fatty acids (MUFA) 23—26% and polyunsaturated fatty acids (PUFA) 38—46% of total fatty acids, respectively). The P/S‐ratio in vegetable products of five months reached a value of 1.5, in all other analyzed products it was around 1. The n‐6:n‐3‐ratio was 10:1 in fruit and cereal products, followed by 11.6:1 in vegetable products of eight and twelve months and 13.5:1 in the group of vegetable products of five months. Since there is a lack of arachidonic acid and docosahexaenoic acid in baby food products, it might be of advantage to consider whether such products should be supplemented by these long‐chain polyunsaturated fatty acids.     

Fatty acid composition of seed oils of some members of the meliaceae and combretaceae families

Seed oils of some members of the Meliceae (six) and Combretaceae (three) were analyzed for their fatty acid composition. In oils of members of both families palmitic acid was the most abundant saturated acid. Trace amounts of short chain (C12–C14) and long chain (C20–C22) saturated acids were detected in some members of the two families. Oleic acid was the most abundant unsaturated acids in the oils of four members of the Meliaceae. However, in the oils ofCedrella odorata andLovoa trichilloides, dienoic acid (C18:2) was the major unsaturated acid. Strikingly high levels of trienoic (C18:3) and monoenoic (C16:1) acids were detected in the seed oils ofC. odorata andEnthandrophragma angolense, respectively. Oleic acid also was the most abundant unsaturated acid in the Combretaceae. The nutritional value and industrial potentials of these oils are given.     

Antioxidant Effect of Nanoemulsions Based on Citrus Peel Essential Oils: Prevention of Lipid Oxidation in Trout

The antioxidant effects of oil‐in‐water nanoemulsion based on edible citrus peel essential oils on the fatty acid composition of rainbow trout fillets stored at 4 ± 2 °C are investigated. Fish fillets are treated with nanoemulsion and stored for 16 days. Lipid samples are converted into fatty acid methyl esters which are then detected by gas chromatagrophy (GC). The results show that palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), vaccenic acid (C18:1?‐7), oleic acid (C18:1?9), eicosenoic acid (C20:1?9), linoleic acid (C18:2?6), linolenic acid (C18:3?3), eicosapentaenoic acid (EPA) (C20:5?3), and docosahexaenoic acid (DHA) (C22:6?3) are the most important fatty acids in fish meat. While polyene index and hypocholesterolemic:hypercholesterolaemic fatty acid ratios decrease in trout fillets during cold storage, thrombogenicity index and atherogenicity index generally increase (especially in control and Tween 80 groups). The concentrations of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) are higher in the treatment groups and the saturated fatty acids (SFAs) are lower in all groups compared to those of the control group. Application of nanoemulsion based on citrus essential oils prevents oxidation of PUFA especially EPA and DHA, thus has potential as a preservative for fish oil. Practical Applications: In recent years, nanotechnological applications have been increasingly applied to the protection of food. Similarly, natural essential oils are used to increase the shelf life of foods. This study demonstrates the combined effect of a new method of nanoemulsions and essential oils on the safety of foods.     

Synthetic Base Stock Based on Guerbet Alcohols

Guerbet (β branched) alcohols of varying chain length of even carbon numbers were synthesized by using single linear fatty alcohols ranging from 1-octanol to 1-dodecanol. All Guerbet alcohols having fewer than 28 carbon atoms and are liquid at 0 °C due to β branching. Synthetic base oils were prepared by reacting commonly available unsaturated fatty acids and dicarboxylic acids with Guerbet alcohols using p-toluenesulfonic acid as a catalyst. These base oils were characterized by physical and tribological properties like viscosity, viscosity index, pour point, flash point, wear scar, weld load, coefficient of friction etc. and compared with commercially available 150 and 500 N base oils.     

Conversion of palmitate to unsaturated fatty acids differs in a Neurospora crassa mutant with impaired fatty acid synthase activity

The Neurospora crassa cel (fatty acid chain elongation) mutant has impaired fatty acid synthase activity. The cel mutant requires exogenous 16:0 for growth and converts 16:0 to other fatty acids. In contrast to wild-type N. crassa, which converted only 42% of the exogenous [7,7,8,8-²H₄]16:0 that was incorporated into cell lipids to unsaturated fatty acids, cel converted 72%. In addition, cel contains higher levels of 18:3^δ9,12,15 than wild-type, and synthesizes two fatty acids, 20:2^δ11,14 and 20:3^δ11,14,17, found at only trace levels in wild-type. Thus, the Δ15-desaturase activity and elongation activity on 18-carbon polyunsaturated fatty acids are higher for cel than wild-type. This altered metabolism of exogenous 16:0 may be directly due to impaired flux through the endogenous fatty acid biosynthetic pathway, or may result from altered regulation of the synthesis of unsaturated fatty acids in the mutant.     

Elongation and desaturation of dietary fatty acids in turbotScophthalmus maximus L., and rainbow trout,Salmo gairdnerii rich

Turbot and rainbow trout, which had previously recieved diets free of fat, were fed [1-14C] fatty acids. The distribution of radioactivity in the tissue fatty acids was examined 6 days later. In rainbow trout fed [1-14C] 18:3omega3, 70% of the radioactivity was present in 22:6omega3 fatty acid. In contrast, turbot fed [1-14C] 18:1omega9, 18:2omega6, or 18:3omega3 converted only small amounts of labeled fatty acids (3-15%) into fatty acids of longer chain length. The major product of the limited modification found in turbot was the dietary acid elongated by 2 carbon atoms.     

Comprehensive Two‐Dimensional Gas Chromatography–Mass Spectrometry Analysis of Different Types of Vegetable Oils

Comprehensive two‐dimensional gas chromatography coupled with time‐of‐flight mass spectrometry (GC×GC‐TOFMS) was applied for detailed characterization of fatty acid profile of 8 vegetable oils. Due to enhanced selectivity and sensitivity characteristics, the GC×GC method yielded more reliable quantification results compared to one dimensional gas chromatography, especially for medium‐chain fatty acids and odd‐carbon number fatty acids, which are present only at trace level. All problematic positional counterparts of unsaturated fatty acids (e.g. C21:0–C20:3 ω6, C20:3ω3–C20:4 ω6 and C20:5 ω3–C22:0), which commonly coeluted in the case of 1D gas chromatography, were baseline resolved. The specific compounds were found for particular vegetable oils, such as γ‐linolenic acid for hempseed oil, heneicosylic acid and tricosylic acid for olive pomace oil, and nervonic acid for mustard oil.     

Some minor fatty acids of rapeseed oils

A number of minor unsaturated fatty acids of rapeseed oil (fromBrassica napus orcampestris) have been isolated by combinations of distillation preparatve gas liquid chromatography and silver nitrate thin layer chromatography, and were further identified by oxidative fission in BF₃-MeOH. Among the shorter chain, all-cis polyunsaturated fatty acids described are 16:3ω3, 16:2ω6 and 14:2ω6. A ubiquitous minor component inunproceessed oils was found to becis-9, cis-12, trans-15-octadecatrienoic acid, with lesser proportions of thetrans-9, cis-12, cis-15 isomer. Among others identified werecis-14:1ω9 and 15:1ω10, the latter accompanied by half as muchtrans-15:1ω10. Particular attention was paid to the proportions of the minor monoethylenic fatty acids of the ω7 series relative to the longer chain major ω9 monoethylenic fatty acids which have been reduced by plant breeding.     

Carduus nigrescens seed oil—A rich source of pentacyclic triterpenoids

Pentacyclic triterpene alcohols (3%), their acetates (18%), and their long chain fatty acid esters (11%), together with triterpene acids (18%), represent ca. 50% of the oil from the seed and pericarp of the thistleCarduus nigrescens Vill. (Compositae). Along with the usual fatty acids, alkaline hydrolysis of this oil gave triterpene alcohols, some of which were identified by gas chromatography-mass spectrometry. Composition of the triterpenoid fraction, as indicated by gas chromatography of the corresponding acetates, was: α-amyrin (6%), β-amyrin (15%), lupeol plus ϕ-taraxasterol (3%), erythrodiol (6%), and oleanolic acid (3%). Several components, representing 16% of the oil, were not identified. The content of pentacyclic triterpenoids is the largest found in plant seed oils.     

Synthesis of fatty acid esters from acid oils using lipase B from Candida antarctica

Esterification of corn and sunflower acid oils with straight‐ and branched‐chain alcohols were conducted using lipase B from Candida antarctica (Novozym 435) in n‐hexane. Sunflower acid oil consisted of 55.6% free fatty acids and 24.7% triacylglycerols, while the free fatty acids and triacylglycerols contents of corn acid oil were 75.3% and 8.6%, respectively. After 1.5 h of methanolysis of sunflower acid oil, the highest fatty acid methyl ester content (63.6%) was obtained at 40 °C and the total fatty acid/methanol molar ratio was 1/1, using 15% enzyme based on acid oil weight. The conversion of both acid oils with straight‐ and branched‐chain alcohols was not significantly affected by the chain length of the alcohols. However, the lowest fatty acid methyl ester content (50%) was obtained in the reaction of corn acid oil with methanol. Sunflower acid oil was converted to fatty acid esters using primer alcohols such as n‐propanol, i‐ and n‐butanol, n‐amylalcohols, n‐octanol, and a mixture of amylalcohol isomers, resulting in a fatty acid ester content of about 70% at 40 °C.     

The Composition of the Cuticular and Internal Free Fatty Acids and Alcohols from <Emphasis Type="Italic">Lucilia sericata</Emphasis> Males and Females

GC, GC-MS, and HPLC-LLSD analyses were used to identify and quantify cuticular and internal lipids in males and females of the blow-fly (Lucilia sericata). Sixteen free fatty acids, seven alcohols and cholesterol were identified and quantitatively determined in the cuticular lipids of L. sericata. Cuticular fatty acids ranged from C(6) to C(20) and included unsaturated entities such as 16:1n-9, 18:1n-9, 20:4n-3 and 20:5n-3. Cuticular alcohols (only saturated and even-numbered) ranged from C(12) to C(20) in males and C(10) to C(22) in females. Only one sterol was found in the cuticular lipids of both males and females. 23 free fatty acids, five alcohols and cholesterol were identified in the internal lipids. Internal fatty acids were present in large amounts-7.4 mg/g (female) and 10.1 mg/g (male). Only traces of internal alcohols (from C(14) to C(26) in males, from C(14) to C(22) in females) were found in L. sericata. Large amounts of internal cholesterol were identified in L. sericata males and females (0.49 and 0.97 mg/g of the insect body, respectively).     

Neutral lipids of chickpea flour and protein isolates

The neutral lipids composition of defatted chickpea flour and two types of protein isolates has been studied. The main compounds in neutral lipids are triacylglycerols, free fatty acids, and diacylglycerols. Other compounds present are wax esters, free fatty alcohols, and free sterols. The main fatty acids in neutral lipids are C_18:2 and C_18:1 among the unsaturated, and C_16:0 and C_18:0 among the saturated acids. Free and esterified alcohols range from C_16:0 to C_28:0, the majority being those with an even number of carbon atoms. Sterols observed are β-sito-sterol, campesterol, stigmasterol, and δ-5-avenasterol. Triacyl-glycerols are partially hydrolyzed, and the amounts of unsaturated sterols and unsaturated fatty acids are reduced as a result of the chemical treatment during production of the protein isolates.     

Stearidonic acid: A plant produced omega‐3 PUFA and a potential alternative for marine oil fatty acids

Omega‐3 (n‐3) fatty acids are widely recognized as being important in regulating many inflammatory disorders in man. However, metabolism of the parent n‐3 fatty acid α‐linolenic acid (ALA, 18:3n‐3) to the highly unsaturated bioactive fatty acids; eicosapentaenoic acid (EPA, 20:5n‐3) and docosahexaenoic acid (DHA, 22:6n‐3), in the body is limited. The first product in the pathway leading to EPA/DHA is the post‐Δ6 desaturase metabolite stearidonic acid (SDA, 18:4n‐3). The activity of the Δ6‐desaturase enzyme is low in man and can be adversely influenced by several environmental factors including dietary fat. SDA has been shown, in several studies, to be rapidly and efficiently converted to EPA which is a probable factor in its bio‐activity. The main source of EPA and DHA in diet is fish oil which, owing to over‐fishing and its extensive use in aquaculture feed, is becoming a scarce resource. There clearly exists a need for a renewable source of a lipid containing the highly unsaturated n‐3 fatty acids EPA, DHA or SDA. Although the highly unsaturated fatty acids (HUFA) have been commercially produced in micro‐organisms neither EPA nor DHA has been shown to exist in any quantity in land‐based plants. SDA is however found in several fungal and algal species and also in a small number of plant seed oils. Plants from the Boraginaceae family notably Echium species are particularly rich in SDA and Echium plantagineum has been grown commercially. Other plants from the Boraginaceae are being investigated and several have been identified that may offer benefits over Echium spp. Transgenic plants containing high levels of SDA have also been reported but engineering EPA or DHA into genetically modified higher plants is proving elusive. SDA‐containing lipids are of great interest in a number of areas such as fortified foods, dietary supplements, medicinal foods, pharmaceuticals and personal‐care products.     

The monoene and other Wax alcohols of human skin surface lipid and their relation to the fatty acids of this lipid

1) Wax alcohols (as acetates) were isolated from human skin surface lipid and separated into a saturated and a monoene fraction. 2) Four main chain types were found for both saturated and monoene alcohols: normal even, normal odd, iso and anteiso. ("Even" and "odd" refer to the number of C-atoms in the straight chain.) 3) The monoene alcohol acetates were separated into homologues of each chain type by preparative gas-liquid chromatography (GLC) and the positions of the double bonds for each homologue were determined by analytical GLC of the original fraction, its hydrogenated derivative, and the products it formed by reductive ozonolysis. 4) The fragments formed by reductive ozonolysis of the monoene alcohol acetates were compared to those formed from the total monoenoic fatty acids (as methyl esters), both obtained from the same sample of surface lipid. (Comparisons were best made by ozonolysis of a portion of the entire sample of each ester group. a) The terminal ends of both groups of monoene fatty chains yielded a very similar pattern of aldehydes in terms of types and amounts. This could be explained by the hypothesis that both fatty acid and fatty alcohol chains of lengths ranging mainly from C(14) to C(18) were first biosynthesized, then desaturated at Delta6. b) The functional group ends gave a distinct pattern of aldehyde esters for the acids and another for the alcohols. Both patterns consisted nearly entirely of members having aneven number of C-atoms from the double bond to the functional group. This suggested that the members of each pattern were formed by chain extensions of an integral number of C(2) units beyond the lengths arrived at in 4a). Thus 71% of the fatty acid monoenes were not extended, 25% were extended by 1 C(2) unit and the remainder extended from 2 to 5 C(2) units, whereas nearly all the fatty alcohols were extended mainly by 2, 3 or 4 C(2) units, with decreasing amounts up to 8 C(2) units. 5) A small amount ( approximately 5%) of odd chain aldehyde esters for both fatty acids and fatty alcohols were found and some unidentified alcohols were detected.     

Fatty Acids Profile of <Emphasis Type="Italic">Alphitonia neocaledonica</Emphasis> and <Emphasis Type="Italic">Grevillea exul</Emphasis> var. <Emphasis Type="Italic">rubiginosa</Emphasis> Seed Oils,Occurrence of an ω5 Series

This is the first report of the chemical composition of Alphitonia neocaledonica (AN) and Grevillea exul var. rubiginosa (GER) seed oils. Using retention indices and gas chromatography–mass spectrometry, an unusual family of unsaturated ω5-fatty acids has been identified. These include 14:1, 16:1, 18:1 and 20:1. Identification of the unsaturated fatty acids was confirmed by formation of DMOX derivatives which gave characteristic and easily interpreted mass spectra. DMDS adducts were used to identify the positions of double bonds in the monounsaturated fatty acids. The major fatty acids were 16:1ω5 (45.6%) and 18:1ω9 (20.9%) for GER and 18:2 (23.6%) and 18:3 (20.4%) for AN. The total ω5-monoenes were 63.4 and 21.5% for GER and AN, respectively. The seed oils of AN and GER can be considered as a good source of ω5-monoenes, especially for GER. The occurrence of the ω5-monoenes in Alphitonia neocaledonica can at present be considered as an exception within the Rhamnaceae family. Except for Ziziphus jujuba var. inermis, no species of this family has been described with a broad profile of ω5-monoene fatty acids.     

Lipid Adaptation of Shrimp Rimicaris exoculata in Hydrothermal Vent

The shrimp Rimicaris exoculata is the most abundant species in hydrothermal vents. Lipids, the component of membranes, play an important role in maintaining their function normally in such extreme environments. In order to understand the lipid adaptation of R. exoculata (HV shrimp) to hydrothermal vents, we compared its lipid profile with the coastal shrimp Litopenaeus vannamei (EZ shrimp) which lives in the euphotic zone, using ultra performance liquid chromatography electrospray ionization‐quadrupole time‐of‐flight mass spectrometry. As a result, the following lipid adaptation can be observed. (1) The proportion of 16:1 and 18:1, and non‐methylene interrupted fatty acid (48.9 and 6.2 %) in HV shrimp was higher than that in EZ shrimp (12.7 and 0 %). While highly‐unsaturated fatty acids were only present in the EZ shrimp. (2) Ceramide and sphingomyelin in the HV shrimp were enriched in d14:1 long chain base (96.5 and 100 %) and unsaturated fatty acids (67.1 and 57.7 %). While in the EZ shrimp, ceramide and sphingomyelin had the tendency to contain d16:1 long chain base (68.7 and 75 %) and saturated fatty acids (100 and 100 %). (3) Triacylglycerol content (1.998 ± 0.005 nmol/mg) in the HV shrimp was higher than that in the EZ shrimp (0.092 ± 0.005 nmol/mg). (4) Phosphatidylinositol and diacylglycerol containing highly‐unsaturated fatty acids were absent from the HV shrimp. (5) Lysophosphatidylcholine and lysophosphatidylethanolamine were rarely detected in the HV shrimp. A possible reason for such differences was the result of food resources and inhabiting environments. Therefore, these lipid classes mentioned above may be the biomarkers to compare the organisms from different environments, which will be benefit for the further exploitation of the hydrothermal environment.     

Studies on characterization and variation in triglyceride fatty acids from punt/us sarana body lipids

Body lipids of P. sarana of four different sizes were fractionated into phospholipids, neutral lipids, nonsaponifiables, total fatty acids, polyunsaturated, monounsaturated and saturated fatty acid fractions. Percentage composition of each fraction was determined. The triglyceride fatty acids were identified by thin layer and gas liquid chromatography. C₈ to C₂₃ fatty acids including both odd numbered and branched chain acids were detected. The major constituents were C₁₄, C₁₅, C₁₆, C_16:1, C₁₈ C_18:1, C_18:2, C_18:3; forty-three other acids were detected in lower proportions. Composition of each fatty acids and their variation with size have been discussed.tP. sarana body lipids in general showed a behavior typical of fresh water fish by having a higher percentage of saturated C₁₆ and unsaturated C₁₈ acids and a lower percentage of unsaturated C₂₀ acid.     

Peanut oil: Compositional data

The major fatty acids of peanut oil acylglycerols are palmitic (C16:0), oleic (C18:1), and linoleic (C18:2) acids, and only a trace amount of linolenic fatty acid (C18:3) is present. Thus they have a very convenient oxidative stability and have been considered premium cooking and frying oils. This paper provides information about compositional data of peanut oil taking into account major (triacylglycerols and their fatty acids) and minor (free fatty acids, diacylglycerols, phospholipids, sterols, tocopherols, tocotrienols, triterpenic and aliphatic alcohols, waxes, pigments, phenolic compounds, volatiles, and metals) compounds. Moreover, the influence of genotype, seed maturity, climatic conditions, and growth location on peanut oil chemical composition is considered in the present report. In addition, peanut oils from wild species found in South America as well as from peanut lines developed through conventional breeding are also compared.