Korrelation der subjektiven und objektiven Bewertung der Farbe von pflanzlichen Ölen

Correlation of the Subjective and Objective Evaluation of the Colour of Vegetable Oils The Process of bleaching of rapeseed oil was investigated in the present work with continuously increasing and decreasing concentration of adsorption substances. The colour index of the oil was described in the coordinate system of the trichromatic method and by means of a colour chart. The correlation between the objective and subjective evaluation of the colour was mathematically formulated.     

Polarographische Bestimmung von Hydroperoxiden in Ölen

Polarographic Determination of Hydroperoxides in Oils The application of direct current polarography for the determination of hydroperoxides in oils has the following advantages over other methods: 1) specific for the hydroperoxides, 2) independent of the structure of hydroperoxides, 3) even very small amounts (upto 10^?6 mol/1) are detectable and 4) relatively short time is required. In comparison to chemical determination the accuracy of the polarographic determination is ± 3% and in case of very small hydroperoxide content (<10^?5 mol/1), it is ± 10%.     

Die kontinuierliche Hydrierung von Ölen und Fetten

Continuous Hydrogenation of Oils and Fats The processes described till now for the continuous hydrogenation of glycerides are reviewed. The various systems are classified from the viewpoint of the reactor involved and their advantages and disadvantages are discussed. As an example of a modern plant for continuous hydrogenation, the reactor of BUSS AG, Basel, is described in details and its operational characteristics in the selective hydrogenation of fish oil are reported. The effect of pressure, temperature and catalyst concentration on the dilatation properties of the products at various temperatures and iodine values is given. Pressure was found to be the most important factor governing the selectivity. Finally, the consumption figures of a 150 to and a 250 to per day plant are presented.     

Dekontamination von Ölen, Ölsaaten und -früchten von Cäsium-137

Decontamination of Oils, Oilseeds and Oil-Bearing Fruits from Caesium-137 It was shown by model experiments that caesium-137 is removed partly from raw oils and fats during deacidification and to a considerable extent during bleaching. Totally contaminated oilseeds and oil-bearing fruits can be freed from caesium-137 by diffusion, for which 10% sodium chloride or potassium chloride solutions were used. Recirculation and continuous removal of caesium ions which have already entered in the solution intensify and accelerate the decontamination. The attainable degree of decontamination is dependent on the plant material to be treated.     

Bestimmung von Schwermetallen in Ölen,Fetten und Futtermitteln

Determination of Heavy Metal Traces in Oils, Fats and Feeding-Stuffs Atomic absorption spectroscopy has proved to be the best method for the determination of lead, cadmium and mercury in fats, oils and feeding-stuffs, whereas colorimetry is best for the determination of arsenic. For each substrate the most suitable digestion method is described. Recoveries and detection limits of the determination methods are shown.     

Schnelle atomabsorptionsspektrometrische Bestimmungen von Spurenelementen in Ölen und Fetten

Fast Atomic Absorption Measurements of Trace Elements in Oils and Fats by Reduced Sample Preparation Atomic absorption measurements of trace elements in oils and fats can be performed either in aqueous solutions after wet digestion or directly inorganic solutions of the samples. But wet digestions are time-consuming and may cause contamination. Direct measurements are fast but are influenced in uncontrolled manner by the matrix or the state of the trace elements in the sample. Such possible errors can be widely reduced if the samples are treated with concentrated formic acid before being measured directly in an organic solution. With formic acid the organic standards can also be prepared from aqueous solutions.     

Separation von Feststoffen aus Fetten und Ölen durch Elektrophorese

Separation of Solids from Fats and Oils by Electrophoresis The development of PETRECOR ELECTROFILTER^TM SEPARATOR provides the food industry with plants that enable the separation of solid particles, including those in the submicron region (< 0.5 μm), from fats and oils with the aid of high-voltage electrical field. The most important commercial application is the removal of bleaching earth and nickel catalyst; a final polishing filtration becomes unnecessary. Results of pilot plant operation show, for example in the removal of nickel catalyst from hydrogenated soybean oil, a continuous reduction of nickel from 500 ppm to < 0.15 ppm. These plants are completely closed systems under slight pressure with a definite precalculated capacity for solids; the latter can be removed by a simple regeneration process involving rinsing with the product to be treated. This regenerating liquid is a pumpable suspension containing ca. 5% solids; it is subjected to further treatment. Plants of various sizes with respect to maximum flow rate and capacity are available. The layout is always done for the specific application.     

Eine Schnellmethode zur Bestimmung von Lösungsmittelresten in extrahierten Ölen

A Rapid Method for the Determination of Residual Solvents in Extracted Oils The content of petroleum solvents and trichloroethylene can be determined in extracted vegetable oils within 15 minutes, upto a limit of 0.01%, at an accuracy which is adequate for the practice. Air is blown through the sample of oil at room temperature and the escaping air current containing the solvent is passed through Dräger indicator tubes, such as hydrocarbon tube KW 2, or trichloroethylene tube 10/a. Length of the discoloured zone is directly proportional to solvent content of the oil.     

Chlorophyll-Abbauprodukte in pflanzlichen Ölen

Chlorophyll Degradation Products in Vegetable Oils The colour of crude vegetable oils depends, apart from carotenoids and other substances, on the presence of chlorophylls or their degradation and isomerisation products. These coloured products can be more or less effectively removed during subsequent steps of refining. These substances exhibit natural fluorescence, and the presence of different structural elements or functional groups permits their separation in reversed-phase chromatography. Using HPLC with fluorescence detection, a more detailed investigation of such products in vegetable oils is possible.     

Bestimmung von Pentan als Indikator für die oxidative Ranzigkeit von Ölen

Determination of Pentane as an Indicator of Oil Rancidity Pentane, determined by a headspace gas chromatographic method, is an excellent indicator of oil rancidity. The methodology applied is very simple and could be performed in an oil laboratory without purchasing additional equipment. The amount of pentane correlated well with the iodometrically determined peroxide value (R²-value of 0.976). Heating the oil sample in air followed by an estimation of pentane is an alternative means to assess oil stability against oxidative deterioration.     

Säulen-chromatographische Bewertung der Oxydationsstufe von Fetten und Ölen

Column Chromatographic Estimation of the Extent of Oxidation of Fats and Oils Oxidized fats and oils can be separated into oxidized and unoxidized fractions by column chromatography with aluminium oxide as adsorbent and benzene and ethanol-diethyl ether mixture as eluting solvents. The method is suitable for the evaluation of advanced oxidation where chemical methods can lead to false results.     

Quantitative Bestimmung von polycyclischen aromatischen Kohlenwasserstoffen in Fetten und Ölen

Quantitative Determination of Polycyclic Aromatic Hydrocarbons in Fats and Oils A method, based on liquid-liquid partition and column as well as thin-layer chromatography, for the qualitative and quantitative UV-spectrophotometric determination of 13 polycyclic aromatic hydrocarbons present in fats and oils, is reported. The limit of detection lies between 0.1 to 0.5 μg/kg, the recovery between 55 and 60% and the relative standard deviation between 5 and 20%. A determination in duplicate requires about 3 days. Another procedure, requiring a few hours for the determination of groups of the polycyclic aromatic hydrocarbons in 20 g fat or oil, which provides only semi-quantitative results, is reported as well.     

Kolonnenauslegung zur physikalischen Raffination von Ölen - Theorie und Praxis

Column Layout for Physical Refining of Oils - Theory and Practice Because of missing data of phase equilibrium simplifications are often used for the thermodynamic layout of distillative neutralisation of fats and oils. These simplifications do not correctly describe the real behaviour of such systems during distillation. For more than three years trials have been carried out in our pilot plant of physical refining and deodorization. In parallel to these trials computer simulations, using different arrangements for the activity coefficients, have been carried out. The results of the theoretical calculations are compared with the measured data on the basis of some examples.     

Der Futterwert von Fetten und Ölen aus Verarbeitungsprozessen bei Geflügel

Feeding Value of Fats and Oils from Finishing Processes for Poultry Altogether two trials with 22 different fats/oils have been carried out. In the first trial the interesterification and the digestibility of the fatty acids of seven fats and oils from the finishing processes with different contents of polymeres have been determined with broilers, aged 2–3 and 5–6 weeks as well as adult cocks. The age of the animals and the shares of the fatty acids were of high influence on the feeding value. In the second trial the fattening performance of broilers that had got ratios of 13 different frying oils, bleaching earth oils or distillation residues, was determined. The results with frying oils were successful, those with bleaching earth oils were moderate and with distillation residues extremely bad. A dependence between the content of polymeres and the feeding value of fat and oils could not be found out.     

Die polarographische Bestimmung von Tocopherolen und Tocopherylchinonen in Ölen und Fetten

Polarographic Determination of Tocopherols and Tocopherylquinones in Oils and Fats A method for the polarographic determination of α-, γ-, and δ-tocopherols and the corresponding tocopherylquinones in oils and fats was worked out. After saponification of the samples and extraction of unsaponifiable matter with ether, the tocopherylquinones originally present in oils and fats are directly determined polarographically. Tocopherols present in the sample are oxidized quantitatively with cerium(IV) sulfate to the corresponding tocopherylquinones and latter are then likewise polarographed. The presence of substances accompanying tocopherols in the unsaponifiable matter does not interfere with the determination of tocopherols or tocopherylquinones. The tocopherol contents of different oils and fats are given.     

Über die destillative Entsäuerung von Fetten und Ölen

Distillative Deacidification of Fats and Oils Based on the general principles of steam distillation, a method and diagrams for calculating the consumption of stripping steam in the distillative deacidification of various types of fats and oils are given. With the example of distillative deacidification of palm oil, it is shown as to how the minimum consumption of stripping steam is obtained in a two-step process. Subsequently, the corresponding determinations for palm kernel, coconut, peanut and rapeseed oils are shown. The operational scheme of a continuous plant for distillative deacidification and deodorization as well as photos of the fittings of the distilling cylinder are also included.     

Untersuchungen zur Autoxidation von Fetten und Ölen mit Hilfe einer Chemilumineszenz-Methode

Investigations about the Autoxidation of Fats and Oils by a Chemiluminescence Method The oxidative stability of different oils was determined by a Rancimat apparatus. Samples of oils obtained at definite time intervals from the Rancimat were measured by a chemiluminescence method. Thereby the hydroperoxides formed during the first step of the autoxidation and radicals react in presence of a catalyst with Luminol. The results are presented in dependence of the storage time and discussed with relation to the results of the Rancimat apparatus. There is a good correlation between both methods (r = 0.9865).     

Vergleich einiger Methoden zur Bestimmung des Oxiran-Sauerstoffgehalts von Ölen und Fetten

Comparison of a Few Methods for the Determination of Oxirane Oxygen Content of Oils and Fats The accuracy and reproducibility of four methods were compared by multiple determinations of oxirane oxygen contents of 9,10-epoxystearic acid, alone or in conjunction with varnish grade linseed oil, of epoxidized oil, as well as of heat treated oxidized oil. Besides the direct method employing HBr/glacial acetic acid three indirect procedures were tested. The differences amongst the above methods lie in titrating agents and end point indication. Especially with regard to attainable accuracy the method employed by the author involving potentiometric end point indication is distinctly advantageous as compared to coloured indicators. None of the methods tested is applicable for the determination of oxirane oxygen content at a level < 0.01%.     

Löslichkeitsverhalten von fetten Ölen in komprimiertem Kohlendioxid im Druckbereich bis 2600 bar

Solubility Behaviour of Fatty Oils in Dense Carbon Dioxide in the Pressure Range up to 2600 bar Different possibilities to determine the phase equilibrium are shown. A dynamic procedure is developed which allows to evaluate solubility data of fatty oils in dense gases. Construction, functioning and handling of the apparatus are described with which the solubility of soybean oil in dense carbon dioxide is examined in the pressure range up to 2600 bar and in a temperature intervall between 25°C and 80°C. The formation of solubility maxima at a interval between 25°C and 80°C. The formation of solubility maxima at a gas density of 1.06 g/cm³ is found out. The facts which influence the solubility behaviour are discussed and the importance of the results for the extraction of oil seeds is given thought.