998 resultados para C14:0
Resumo:
The structural features of fatty acids in biodiesel, including degree of unsaturation, percentage of saturated fatty acids and average chain length, influence important fuel properties such as cetane number, iodine value, density, kinematic viscosity, higher heating value and oxidation stability. The composition of fatty acid esters within the fuel should therefore be in the correct ratio to ensure fuel properties are within international biodiesel standards such as ASTM 6751 or EN 14214. This study scrutinises the influence of fatty acid composition and individual fatty acids on fuel properties. Fuel properties were estimated based on published equations, and measured according to standard procedure ASTM D6751 and EN 14214 to confirm the influences of the fatty acid profile. Based on fatty acid profile-derived calculations, the cetane number of the microalgal biodiesel was estimated to be 11.6, but measured 46.5, which emphasises the uncertainty of the method used for cetane number calculation. Multi-criteria decision analysis (MCDA), PROMETHEE-GAIA, was used to determine the influence of individual fatty acids on fuel properties in the GAIA plane. Polyunsaturated fatty acids increased the iodine value and had a negative influence on cetane number. Kinematic viscosity was negatively influenced by some long chain polyunsaturated fatty acids such as C20:5 and C22:6 and some of the more common saturated fatty acids C14:0 and C18:0. The positive impact of average chain length on higher heating value was also confirmed in the GAIA plane
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The fatty acids of 18 strains of Bordetella avium, 3 strains of Alcaligenes faecalis, 5 strains of Bordetella bronchiseptica, and 12 strains of a B. avium-like organism were examined by gas chromatography-mass spectrometry. The presence of a significant amount of the acid 2-OH C14:0 characterized B. avium and the B. avium-like organism. B. avium and the B. avium-like organism differed in their relative concentrations of C16:1 and 3-OH C14:0 acids. B. bronchiseptica and A. faecalis were distinguishable by comparison of the relative concentrations of C18:0 and C18:1 acids.
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The six independent elastic constants of sodium nitrate are determined using 10 MHz ultrasonic pulse echo superposition technique over the temperature interval 77 to 300 K. The values obtained at 300 K are C11 = 5.71, C12 = 2.16, C33 = 3.3, C13 = 1.66, C44 = 1.24, C14 = 0.82, and at 77 K C11 = 6.63, C12 = 2.07, C33 = 3.99, C13 = 1.67, C44 = 1.69, C14 = 1.16 all expressed in units of 1011 dyn/cm2.
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Gas-liquid chromatography has been employed for the qualitative and quantitative analysis of the component fatty acids in lipids of oil sardine (Sardinella longiceps). Phospholipids and triglycerides of the lipids were previously separated by column chromatography before they were converted into the methyl esters of the fatty acids. The predominant acids present in the depot fat of the fish have been found to be C14:0=8.13%, C16:0=27.9%, C18:0=3.8%, C18:1=15.4%., C20:5=10.6% and C22:6=8.8%. Apart from the above acids the distribution of minor acids belonging to Cl8, C20 and C22 groups have also been worked out. The separated phospholipid fraction contained more than 70% polyunsaturated acids of which the important constituents were docosahexaenoic (C22:6=28%) and eicosapentaenoic (C20:5=10.6%). A marked reduction was found in the amounts of polyunsaturated acids in triglycerides, their total amount registering about 20%. This fraction recorded about 48% of C16 acids of which palmitic and palmitoleic acids amounted to 25.8% and 19.1% respectively. Occurrence of odd numbered fatty acids C15 and C17 has also been noted in the phospholipid and composite samples of the fish.
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The purpose of this study, Evaluation the effect of Rosmarinus officinalis and Thymus vulgaris extracts on the stability of poly unsaturated fatty acids in frozen Silver carp minced. Treatments include: Treatment 1 - Control: frozen meat packaged in conventional Treatment 2: Frozen Silver carp minced+Thyme 300 mg/kg in normal packaging Treatment 3: Frozen Silver carp minced+Rosemary 200 mg/kg in normal packaging Treatment 4: Frozen Silver carp minced+Rosemary compound (100 mg/kg) and Thyme (100 mg/kg) in normal packaging After rapid freezing of samples in the spiral freezer by individual quick freezing method, to maintain the cold temperature (-18) °C were transferred. Sampling and measurements to determine the fatty acid profile of the zero phase beginning in the first month and then every ten days, and 15 days in the second month of the third month after the monthly test. Identifying, defining and measuring the fatty acid profile by gas chromatography was performed. In this study, levels of both saturated and unsaturated fatty acids in three experimental and one control were identified as follows: A: saturated fatty acids: Meristic C14: 0/Palmitic C16: 0/Hepta decaenoic C17: 0/Stearic C18: 0/Arashidic C20: 0/B:Mono unsaturated fatty acids: palmitoleic C16: 1-W7/Oleic C18: 1-W9/Gadoleic C20: 1-W9 C:Poly unsaturated fatty acids: Linoleic C18: 2-W6/α-Linolenic C18: 3-W3 D:High unsaturated fatty acids: Arachidonic C20: 4-W6 Eicosapentaenoic acid C20: 5-EPA/W3 Docosahexaenoic C22: 6-DHA/W3 Results of this study was to determine, Thyme and rosemary extracts containing silver carp minced stored in freezing conditions, Stability of different types of fatty acids, monounsaturated fatty acids, poly-unsaturated fatty acids, omega-3 and omega-6 fatty acids are. So that none of the fatty acids measured were not significant 100% increase or decrease, While changes in the fatty acid oxidation during storage time is minimized. The results obtained from the fatty acid profiles and indicators of their and statistical tests show that treatment with rosemary extract More stable during storage (-18) ° C In comparison with the control and other treatments are shown; And at relatively low compared to other treatments and control samples oleic acid and linoleic acid, palmitic more. According to studies,in Silver carp minced that containing rosemary extract, end of the storage period of six months. Were usable, so even rosemary extract the shelf-life examples to increase more than six months.
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通过监测不同培养条件下(灭菌、加选择抑菌剂、未灭菌)土壤中乙草胺残留数量和培养期间微生物标识物磷脂脂肪酸(PLFAs)含量的变化,探讨了以田间推荐量施用乙草胺时,不同微生物群落对乙草胺降解的相对贡献以及乙草胺对黑土微生物群落结构的影响.结果表明:乙草胺易于被微生物降解,其中,细菌对乙草胺的降解作用显著大于真菌,而真菌对乙草胺有更强的耐受能力.施入乙草胺后,各磷脂脂肪酸数量发生了显著变化,C14∶0、C16∶0和C18∶0所指示的土壤微生物量均有所下降;细菌PLFAs数量在培养初期显著降低,而后与对照的差异显著减小,表明细菌活性随着乙草胺的降解有所恢复;在施用乙草胺后的整个培养过程中,土壤真菌PLFAs数量始终低于对照,暗示着乙草胺对真菌的抑制可能是长期而不可逆的.
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Among marine bacteria isolated from the cytotoxic sponge Hymeniacidon perleve, one strain NJ6-3-1 classified as Pseudomonas sp. showed both cytotoxic and antimicrobial activities. Fatty acid analysis indicated that the bacterial strain consists mainly of C16:1, C16:0, C18:1, C18:0, C15:0, C14:0. One unusual 9,10-cyclopropane-C17:0 fatty acid and C26:0 also constitute major components, as well as the existence of squalene, the precursor of triterpenoids. The major metabolites in the culture broth were identified as alkaloids, including diketopiperazines and indole compounds, namely 3,6-diisopropylpiperazine-2,5-dione, 3-benzyl-3-isopropylpiperazine-2,5-dione, 3,6-bis-(2-methylpropyl)-piperazine-2,5-dione, indole-3-carboxaldehyde, indole-3-carboxylic acid methyl ester, indole-3-ethanol, and quinazoline-2,4-dione.
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The most consumed squid species worldwide were characterized regarding their concentrations of minerals, fatty acids, cholesterol and vitamin E. Interspecific comparisons were assessed among species and geographical origin. The health benefits derived from squid consumption were assessed based on daily minerals intake and on nutritional lipid quality indexes. Squids contribute significantly to daily intake of several macro (Na, K, Mg and P) and micronutrients (Cu, Zn and Ni). Despite their low fat concentration, they are rich in long-chain omega-3 fatty acids, particularly docosahexaenoic (DHA) and eicosapentanoic (EPA) acids, with highly favorable ω-3/ω-6 ratios (from 5.7 to 17.7), reducing the significance of their high cholesterol concentration (140–549 mg/100 g ww). Assessment of potential health risks based on minerals intake, non-carcinogenic and carcinogenic risks indicated that Loligo gahi (from Atlantic Ocean), Loligo opalescens (from Pacific Ocean) and Loligo duvaucelii (from Indic Ocean) should be eaten with moderation due to the high concentrations of Cu and/or Cd. Canonical discriminant analysis identified the major fatty acids (C14:0, C18:0, C18:1, C18:3ω-3, C20:4ω-6 and C22:5ω-6), P, K, Cu and vitamin E as chemical discriminators for the selected species. These elements and compounds exhibited the potential to prove authenticity of the commercially relevant squid species.
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In common with many other plasma membrane glycoproteins of eukaryotic origin, the promastigote surface protease (PSP) of the protozoan parasite Leishmania contains a glycosyl-phosphatidylinositol (GPI) membrane anchor. The GPI anchor of Leishmania major PSP was purified following proteolysis of the PSP and analyzed by two-dimensional 1H-1H NMR, compositional and methylation linkage analyses, chemical and enzymatic modifications, and amino acid sequencing. From these results, the structure of the GPI-containing peptide was found to be Asp-Gly-Gly-Asn-ethanolamine-PO4-6Man alpha 1-6Man alpha 1-4GlcN alpha 1-6myo-inositol-1-PO4-(1-alkyl-2-acyl-glycerol). The glycan structure is identical to the conserved glycan core regions of the GPI anchor of Trypanosoma brucei variant surface glycoprotein and rat brain Thy-1 antigen, supporting the notion that this portion of GPIs are highly conserved. The phosphatidylinositol moiety of the PSP anchor is unusual, containing a fully saturated, unbranched 1-O-alkyl chain (mainly C24:0) and a mixture of fully saturated unbranched 2-O-acyl chains (C12:0, C14:0, C16:0, and C18:0). This lipid composition differs significantly from those of the GPIs of T. brucei variant surface glycoprotein and mammalian erythrocyte acetylcholinesterase but is similar to that of a family of glycosylated phosphoinositides found uniquely in Leishmania.
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Various studies have indicated a relationship between enteric methane (CH4) production and milk fatty acid (FA) profiles of dairy cattle. However, the number of studies investigating such a relationship is limited and the direct relationships reported are mainly obtained by variation in CH4 production and milk FA concentration induced by dietary lipid supplements. The aim of this study was to perform a meta-analysis to quantify relationships between CH4 yield (per unit of feed and unit of milk) and milk FA profile in dairy cattle and to develop equations to predict CH4 yield based on milk FA profile of cows fed a wide variety of diets. Data from 8 experiments encompassing 30 different dietary treatments and 146 observations were included. Yield of CH4 measured in these experiments was 21.5 ± 2.46 g/kg of dry matter intake (DMI) and 13.9 ± 2.30 g/ kg of fat- and protein-corrected milk (FPCM). Correlation coefficients were chosen as effect size of the relationship between CH4 yield and individual milk FA concentration (g/100 g of FA). Average true correlation coefficients were estimated by a random-effects model. Milk FA concentrations of C6:0, C8:0, C10:0, C16:0, and C16:0-iso were significantly or tended to be positively related to CH4 yield per unit of feed. Concentrations of trans-6+7+8+9 C18:1, trans-10+11 C18:1, cis- 11 C18:1, cis-12 C18:1, cis-13 C18:1, trans-16+cis-14 C18:1, and cis-9,12 C18:2 in milk fat were significantly or tended to be negatively related to CH4 yield per unit of feed. Milk FA concentrations of C10:0, C12:0, C14:0-iso, C14:0, cis-9 C14:1, C15:0, and C16:0 were significantly or tended to be positively related to CH4 yield per unit of milk. Concentrations of C4:0, C18:0, trans-10+11 C18:1, cis-9 C18:1, cis-11 C18:1, and cis- 9,12 C18:2 in milk fat were significantly or tended to be negatively related to CH4 yield per unit of milk. Mixed model multiple regression and a stepwise selection procedure of milk FA based on the Bayesian information criterion to predict CH4 yield with milk FA as input (g/100 g of FA) resulted in the following prediction equations: CH4 (g/kg of DMI) = 23.39 + 9.74 × C16:0- iso – 1.06 × trans-10+11 C18:1 – 1.75 × cis-9,12 C18:2 (R2 = 0.54), and CH4 (g/kg of FPCM) = 21.13 – 1.38 × C4:0 + 8.53 × C16:0-iso – 0.22 × cis-9 C18:1 – 0.59 × trans-10+11 C18:1 (R2 = 0.47). This indicated that milk FA profile has a moderate potential for predicting CH4 yield per unit of feed and a slightly lower potential for predicting CH4 yield per unit of milk. Key words: methane , milk fatty acid profile , metaanalysis , dairy cattle
Resumo:
This study investigates the quality of retail milk labelled as Jersey & Guernsey (JG) when compared with milk without breed specifications (NS) and repeatability of differences over seasons and years. 16 different brands of milk (4 Jersey & Guernsey, 12 non specified breed) were sampled over 2 years on 4 occasions. JG milk was associated with both favourable traits for human health, such as the higher total protein, total casein, α-casein, β-casein, κ-casein and α-tocopherol contents, and unfavourable traits, such as the higher concentrations of saturated fat, C12:0, C14:0 and lower concentrations of monounsaturated fatty acids. In summer, JG milk had a higher omega-3:omega-6 ratio than had NS milk. Also, the relative increase in omega-3 fatty acids and α-tocopherol, from winter to summer, was greater in JG milk. The latter characteristic could be of use in breeding schemes and farming systems producing niche dairy products. Seasonality had a more marked impact on the fatty acid composition of JG milk than had NS milk, while the opposite was found for protein composition. Potential implication for the findings in human health, producers, industry and consumers are considered.
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This study of UK retail milk identified highly significant variations in fat composition. The survey, conducted over 2 yr replicating summer and winter, sampled 22 brands, 10 of which indicated organic production systems. Results corroborate earlier farm-based findings considering fat composition of milk produced under conventional and organic management. Organic milk had higher concentrations of beneficial fatty acids (FA) than conventional milk, including total polyunsaturated fatty acids (PUFA; 39.4 vs. 31.8 g/kg of total FA), conjugated linoleic acid cis-9,trans-11 (CLA9; 7.4 v 5.6 g/kg of FA), and α-linolenic acid (α-LN; 6.9 vs. 4.4 g/kg of FA). As expected, purchase season had a strong effect on fat composition: compared with milk purchased in winter, summer milk had a lower concentration of saturated fatty acids (682 vs. 725 g/kg of FA) and higher concentrations of PUFA (37.6 vs. 32.8 g/kg of FA), CLA9 (8.1 vs. 4.7 g/kg of FA), and α-LN (6.5 vs. 4.6 g/kg of FA). Differences identified between sampling years were more surprising: compared with that in yr 2, milk purchased in year 1 had higher concentrations of PUFA (37.5 vs. 32.9 g/kg of FA), α-LN (6.0 vs. 5.1 g/kg of FA), and linoleic acid (19.9 vs. 17.5 g/kg of FA) and lower concentrations of C16:0 and C14:0 (332 vs. 357 and 110 vs. 118 g/kg of FA, respectively). Strong interactions were identified between management and season as well as between season and year of the study. As in the earlier farm studies, differences in fat composition between systems were greater for summer compared with winter milk. Large between-year differences may be due to changes in weather influencing milk composition through forage availability, quality, and intake. If climate change predictions materialize, both forage and dairy management may have to adapt to maintain current milk quality. Considerable variation existed in milk fat composition between brands.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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In this work, a CE method for the determination of olive oil acidity was proposed. The method was based on an ethanolic extraction (at 60 degrees C) of the oil long-chain free fatty acids (LC-FFAs) components followed by CE determination in pH 6.86 phosphate buffer at 15 mmol/L concentration containing 4 mmol/L sodium dodecylbenzenesulfonate (SDBS), 10 mmol/L polyoxyethylene 23 lauryl ether (Brij 35((R))), 2% v/v 1-octanol and 45% v/v ACN under indirect UV detection at 224 nm. Although this electrolyte promoted baseline separation of myristic acid (C14:0) (internal standard (IS)) and olive oil major components (palmitic acid (C16:0), oleic acid (C18:1c) and linoleic acid (C18:2cc)) in less than 8 min, after a few injections, the electropherogram profiles were severely altered (peak broadening, migration time shifts, etc.) and the current increased substantially. An adsorption study was conducted revealing that the dissolution of the capillary external polyimide coating during the electrophoretic run caused the detrimental effect. After removal of the capillary tip coating, ten consecutive injections could be performed without any disturbances and this simple procedure was, therefore, implemented during quantitative purposes. The reliability of the proposed method was further investigated by the determination of acidity of an extra virgin olive oil sample in comparison to the established methodology (AOCS method Ca 5a40, alkaline volumetric titration (AVT)). No statistical differences were found within 95% confidence level. A % acidity of 0.39 +/- 0.02 was found for the olive oil sample under consideration.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)