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Regioselective C-H-Functionalization of Fatty Acids and their Methyl Esters Fatty acids and thier methyl esters can be chlorinated preferentially at the terminal methylene groups with N-alkylchloroamines in sulfuric acid. With capric acid and its methyl ester the optimal reaction conditions for the selective chlorination were elaborated and then transferred to longer fatty acids up to stearic acid. The influence of the solvent, the temperature and the nature of different chlorinating reagents on the selectivity was studies. The capillary GC/MS-analysis of the isomeric chlorinated fatty acids is described.  相似文献   

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New Fatty-Derivatives from the Ester Condensation of Methyl Esters of Fatty Acids The preparation of products of ester condensation from methyl esters of fatty acids is discussed and the chemistry of the derivatives as well as the possibilities of their application is reported.  相似文献   

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Fatty Acid Pattern and Tocopherol Contents of Oils from Different Varieties of Sunflower in the Worldwide Cultivation The material available for investigation comprised 9 varieties from two harvests from 6 locations having greatly differing climate. Furthermore, the material from freely flowering plants and that from isolated plants, which were pollinated within the varieties, were investigated. The fatty acid composition is distinctly dependent on the location; linoleic acid content is negatively correlated with oleic acid content, being high in cold regions and low in warm regions. The tocopherol content of the oil varies both with location and variety in isolated plants, whereas in freely flowering plants the differences in tocopherol content between the varieties disappear. Correlations are found between tocopherol content of the oil and oil content of the seed, yet differentiation should be made whether the variations in oil content are due to genetic differences or due to regional factors. Varietal differences in oil content are positively correlated in both years and regional differences are negatively correlated with the tocopherol content of the oil.  相似文献   

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Post Deodorization Condensates from Soya and Rape Oils as a Source of Tocopherols For refining of different kinds of plant oils the same industrial installations are used. The qualitative and quantitative composition of tocochromanols obtained from post deodorization condensates depends on the refined oil. The influence of the quantity of refined oils in the process on quantitative changes of tocopherols in the condensates was investigated. We found, that for the eventual obtaining of tocopherol concentrates from them, it is better to use soya post deodorization condensate. The maximum concentration of tocopherols in soya condensate was found after deodorization of approximately 26 tons of the oils at an installation yield of about 3.5 tons per hour.  相似文献   

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The Employment of rapeseed Oil in Compounded Rations for Fattening Pigs in Comparison with Soya Bean Oil, and the Influence of these Feeding Oils on the Fatty Acid Pattern of Pig Fat Feeding oils improve the energy content of rations for fattening pigs in consequence of their high concentration of energy, and they prevent the formation of milling diet. Their part of the ration is de- limited by the content of polyen acid, above all the content of linoleic acid. In soya bean oil it amounts about 2.0–2.5 per cent. According the Swiss results the polyen acid content must not be higher than 12 per cent of all fatty acids; sometimes there are recommended 15 per cent. Rapeseed oil of 00–seed contents only 50 per cent of polyen acid and only 40 per cent of linoleic acid of their part in soya bean oil. The present tests confirm anew the close relation between the polyen acid content of the ration and that of the fatty tissue of pigs. Female slaughter pigs tend to higher contents of linoleic acid as castrated males. By mean of an addition of 4 per cent rapeseed oil there were caused content of linoleic acid in the tested fatty tissues, which may acceptable in processed products.  相似文献   

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Influence of light and contents of tocopherols on the oxidative stability of fatty acid methyl esters The oxidative stability of different plant oil based fatty acid methyl esters can be estimated by determining the induction period with the active oxygen method. Measuring the volatile and oil soluble acids for a long period preceding the induction period shows that the values are approaching a certain limit. Even if the esters do not differ dramatically in the composition of fatty acids it is a fact that the different production processes influence the amount of tocopherols significantly. The exclusion of light is more crucial than the exclusion of air when storing plant oil based fatty acid esters.  相似文献   

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Preparation, Analysis and TLC Separation of Partial Esters of Fatty Acids with Erythritol Direct esterification of 99% capric acid, lauric acid, myristic acid, palmitic acid and stearic acid with meso-erythritol (1,2,3,4-butanetetraol) in mole ratio of 1 : 1.25 yielded partial esters of erythritol which were analyzed by chemical values and TLC separation. Using boric acid impregnated silica gel 60 precoated plates all the theoretically possible positional isomers of mono-, di-, tri- and tetraesters of erythritol (9 fractions) and further four 3,4-hydroxy-tetrahydrofuran-mono- and diesters (both cis- and trans compounds), that were formed as side products by dehydration and 1,4 ring closure from 1,2,3,4-butanetetraol, could be detected. Similarly, the unknown TLC fraction of 1,2,4-butanetriol partial ester, as reported earlier, could be identified as 3-hydroxy-tetrahydrofuran fatty ester by chemical values, elementary analysis, molecular weight determination and synthesis. Moreover, erythritol, 1,2,4-butanetriol, 3,4-hydroxy-tetrahydrofuran and 3-hydroxy-tetrahydrofuran were separated by TLC.  相似文献   

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Isolation and Structure Determination of the Polybranched Fatty Acids from Fish Oil From a sample of sea fish oil, three saturated polymethyl branched fatty acids could be separated in pure state as methyl esters by using urea adduct, column chromatography and distillation methods. These could be identified as 4,8,12-trimethyl-tridecanoic acid, 2,6,10,14-tetramethyl-pentadecanoic acid and 3,7,11,15-tetramethyl-hexadecanoic acid, with the help of molecular weight determination, ultimate analysis, IR-, NMR- and mass-spectroscopy. The structures could be proved by synthesis. Many other branched chain fatty acids were synthesised for comparison. The synthesis and the infrared spectrums of these compounds are given in details.  相似文献   

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Changes of rapeseed and linseed oil during processing During processing of crude oil in a large oil mill, three samples each of rapeseed and linseed were investigated at each processing stage, i.e. press oil, solvent-extracted oil, mixed oil, and degummed/caustic refined oil. In the case of rapeseed also bleached and desodorized oils (230°C; 3.0 mbar for 2 h) were investigated. Rapeseed and linseed oil showing the typical major fatty acids contained less than 1% trans-isomeric fatty acids (trans fatty acids = TFA). Linseed oil had a similar TFA-concentration as rapeseed oil, and the concentrations did not change during the processing stages up to degummed/caustic refined oil, and were also unchanged in the bleached rapeseed oil. Desodorization of rapeseed oil, however, trebled the TFA concentration to 0.58%. The detected tocopherol patterns were typical of rapeseed and linseed oils. There was no difference between mixed oil and degummed/caustic refined oil in the total concentration of tocopherols. Neither had bleaching any effect. Rapeseed oil desodorization diminished total tocopherol concentration by 12% from 740 mg/kg to 650 mg/kg. Due to degumming/caustic refining the phosphorus concentration of both oils decreased to less than a tenth compared to mixed oil. Other elements determined in degummed/caustic refined rapeseed oil were not detectable (manganese < 0.02 mg/kg, iron < 0.4 mg/kg, copper < 0.02 mg/kg, lead < 10 μg/kg) or only as traces zink 0.1 mg/kg, cadmium 2 μg/kg). In linseed oil, which initially showed a higher trace compounds concentration, a significant decrease was found by degumming/caustic refining. Iron could not be detected. There were traces of zinc, manganese, copper, lead, and cadmium. There was no difference between the acid values of rapeseed and linseed crude oil. Acid value decreased drastically already during the degumming/caustic refining stage. The crude linseed oils had a higher peroxide value, anisidine value and diene value than the corresponding crude rapeseed oils. With peroxide values of ≤ 0.1 mEq O2/kg found in almost all investigated rapeseed oils, no effect of refining could be detected. The anisidine value showed an increase after bleaching. Desodorization trebled the diene value.  相似文献   

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The Fatty Acid Composition of Almond Oil - A Critical Discussion The range of fatty acid compositions found in various almond oils traded internationally sometimes does not correspond to the published permissible range in pharmacopeias (e.g., DAB 9). In the literature, there have been various reports of adulteration, but also of greater variability of almond fatty acid composition depending on strain and geographical provenience. The problem is discussed and a series of recent analytical data is presented.  相似文献   

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Preparation, Analysis and TLC-Separation of Partial Esters of Fatty Acids with Polybasic Alcohols Direct esterification of 99% capric acid, lauric acid, myristic acid, palmitic acid and stearic acid with ethyleneglycol, diethyleneglycol, thiodiethyleneglycol, triethyleneglycol, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2,5-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,2,4-butanetriol, glycerol, 1,2,6-hexanetriol, trimethylolpropane and pentaerythritol in a molar ratio of 1 :1.25 yields 100 different partial esters of fatty acids. These partial esters are extensively freed from the polyhydric alcohols by washing with sodium sulfate solution and recrystallization in ethanol. Chemical constants and TLC-separation into classes and into polyhydric alcohols permit the evaluation of these compounds as emulsifiers, stabilizers and solubilization acids. All the partial esters of the fatty acids are mixtures, which can be separated by TLC according to the polyhydric alcohol moiety into monoester, diester, triester and tetraester; furthermore, the separation of positional isomers of monoesters and diesters is possible. Several observations made during the synthesis and analysis of partial esters of fatty acids are reported.  相似文献   

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Enzymatic Preparation of Solid Fatty Acid Monoglycerides Lipases can be used to synthesize monoglycerides from solid fatty acids and glycerol. We have examined the conditions of such reaction systems with a view to developing a simple technical process. The selectivity of the Penicillium cyclopium and Rhizopus sp. lipases were studied at high rates of fatty acid turnover. By the correct choice of lipase, temperature and water content, the reaction may be steered in the direction of either monoglycerides of diglycerides. Using the Penicillium lipase under narrowly defined reaction conditions a highly selective monoglyceride synthesis is possible. Di glycerides are almost the sole products when using the Rhizopus lipase at 40°C. At 20°C, but under otherwise identical conditions, the main products are monoglycerides. The Penicillium lipase catalyzes the synthesis of monoglycerides at both 20°C and 40°C, provided that the water content of the glycerine is less than 10%. At a glycerol concentration of 80% the selectivity changes such that more diglycerides are formed. The enzymatic synthesis of glycerides can be so regulated that more than 95% of the available fatty acid is incorporated into monoglyceride. After melting the reaction mixture and allowing it to stand for less than an hour, the phases separate and excess glycerol can be separated very simply. A product conforming to industry specifications can then be produced by distilling off the trace amounts of remaining glycerol from the lipid phase.  相似文献   

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Influence of Variety, Location and Individually Defined Climatic Factors on the Tocopherol Content of Rapeseed Oil The total tocopherol content was determined in the material from different breeding lines, from field experiments (7 varieties from 3 German and 3 foreign locations) as well as from a phytotrone experiment in which the climatic conditions, such as temperature and day length, were varied. Genetic variations were detected predominantly in the breeding material which showed distinct differences between the breeding lines “low-erucic”, “low-glucosinolate” and “high-linoleic”. In the material obtained from field experiments, distinct differences were observed due to location, however, very little difference between the varieties was detected. Studies on the effect of climatic factors, such as temperature and day length, carried out in phytotrone experiments revealed that both of these factors affect the tocopherol content; higher temperatures and shorter periods of light (short day) increase the tocopherol content.  相似文献   

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Fatty Acid Composition of Rapeseed, Soybean, Sunflower and Peanut Oils Alterations in the mode of cultivation of oilseeds have brought forth considerable fluctuations in the composition of vegetable oils in the past decade. It is therefore desirable to report occasionally the new analytical figures on vegetable oils, whose source and past history are exactly known.  相似文献   

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