Bestimmung des Xanthophyllgehaltes von Pflanzenölen

Determination of Xanthophyll Content of Vegetable Oils The DGF official method F — II 2 enables the separation of carotenoid hydrocarbons from the unsaponifiables using a Al₂O₃ column. This method can be extended by the successive use of polar solvents. Thus, polar carotenoids can also be separated. Spectrum of each fraction from the Al₂O₃ column is obtained and the fractions are further separated in a MgO-celite column. Identification of individual carotenoids is done on the basis of absorption spectra as well as the nature and number of polar groups determined by thin-layer chromatography on silica gel plates. Content and composition of carotenoids in several vegetable oils, such as soybean, sesame, sunflower, corn germ and low-erucic rapeseed oil were determined by this technique. All these oils contain mainly dihydroxy carotenoids.     

Vitamin E und Haltbarkeit von Pflanzenölen

Vitamin E and stability of vegetable oils. The main occurrence of vitamin E basing on its synthesis and its lipophilic character are vegetable oils, seeds, nuts and cereals. The most important task of tocopherols are their antioxidative capacity in food lipids. The antioxidative potential of tocotrienols in comparison to their corresponding tocopherols is lower. According to the chemical structure γ- and δ-tocopherol are more effective than α-tocopherol. An improvement of the antioxidative capacity is possible by controlled adding to tocopherol compounds as well as by the use of synergists like ascorbylpalmitate. For this improvement the composition of fatty acids, the tocopherol content in native oil and the circumstances of the oxidation should always be considered.     

Enzymatische Phosphatidentfernung aus Pflanzenölen

The Enzyme-Catalyzed Degumming Process of Vegetable Oils The new degumming process EnzyMax is the first to use a natural enzyme as a biocatalyst for phosphatide removal from vegetable oils. The enzyme Phospholipase A2 splits off the fatty acid linked in the sn-2 position of the phospholipid molecule thus imparting oil-insolubility to the remaining 1-acyl-lysophospholipid and making it amenable to separation. The EnzyMax degumming process can be used on all kinds of oil seed and varying oil qualities with consistently good performance. Even the addition of small enzyme amounts of abt. 700 lecitase units per kg of oil reduces the residual phosphorus concentration to below 10 ppm. As a result, chemical refining can be replaced by physical refining thus eliminating the need for neutralization, soapstock splitting and waste water treatment.     

Beeinflussung des Bleichprozesses bei Pflanzenölen

Influencing the Bleaching Processes of Vegetable Oils The report describes the influence of the acid-, water- and bleaching earth concentration to the parameters lovibond red, the content of carotene, phosphorus and heavy metals, the peroxid-, the anisidine- and extinction value at 232 nm. As an acid the citric acid has been used in different concentrations. After a bleaching process at 90°C the palm oil was bleached in a heat-bleaching-process at 260°C and a pressure of 1 mbar. The possibility of getting good bleaching with 0.5% bleaching earth by optimizing the bleaching process will be shown.     

Umweltrelevante Kriterien zur Anwendung von Pflanzenölen und deren Derivaten im Schmierstoffbereich

Environmental criteria for the use of vegetable oils and their derivates in lubricants The motive behind the use of harvestable raw materials and their derivates in lubricants is their extraordinary environmental compatibility, and the substitution of mineral oil with biodegradable base oils is a primary objective. In the meantime, environmentally friendly, biodegradable alternatives are available for almost all mineral oil-based lubricants. In 1997, about 40000 tons of rapidly biodegradable lubricants were sold in Germany alone, about 4.5% of total lubricant consumption. An increase in this share is the aim of various measures taken by governments and authorities. In general, it is accepted that potentially more than 90% of all lubricants could be manufactured from harvestable raw materials.     

Isomere Monoensäuren in Pflanzenölen

Isomeric Monoenoic Acids in Vegetable Oils In the scope of systematic studies the fatty acids of oils from seed and fruits of 38 plants are investigated for presence of isomeric monoenoic acids with 16, 18 and 20 C-atoms. All analyzed oils contain between 2 and 4 hexadecenoic, octadecenoic and icosenoic acids with different position of the double bound. Vaccenic acid, the cis-11-octadecenoic acid, is always found in low quantities. Its share depends within certain limits on the content of the oils of cis-9-hexadecenoic acid, the so-called palmitoleic acid. Petroselinic acid, cis-6-octadecenoic acid, is found in apiaceae oils and also in the seed oil of some other plant families. Besides, 14 of the investigated oils contain low quantities of ω5-monoenoic acids.     

Motorenöle auf der Basis von Pflanzenölen – ein neuer Ansatz

Vegetable oil-based engine oils – A promising start These days most engine lubricants contain petrochemical base oils. A research project looked into the possibility of using vegetable oils and their derivatives (ester oils) for lubrication of four-stroke engines. The environmentally friendly, high-performance engine oils successfully tested in the first project were based on saturated esters and contained a zinc- and polymer-free additive package. Also realized was the second objective of a completely new lubrication concept which allows for the first time the use of unmodified rapeseed or sunflower oil for engine lubrication. The procedures mentioned here compensate for the basically poor ageing resistance of vegetable oils by a progressive renewal of the oil. The used oil is mixed with the fuel and burned without any detrimental effects on exhaust composition. Only low-ash and zinc-free additives were added to the vegetable oils. Initial and positive application know-how was gathered from a number of diesel engines using this combination of special oil and the novel lubrication concept. Environmentally friendly oils being constantly renewed in stationary engines are a promising start.     

Die Entsäuerung von Pflanzenölen mit Ammoniak Eine umweltfreundliche Raffinationsmethode

Deacidification of Vegetable Oils with Ammonia – An Environmentally Safe Refining Method Compared to conventional deacidification of vegetable oils using sodium hydroxide, neutralization with aqueous ammonia has the advantage of being safe to environment, because the deacidification agent can be repeatedly reused. Oils, especially soybean oil with low degree of oxidation, can be fully deacidified only with the help of ammonia. A post-refining with 0.5 N sodium hydroxide at 95-100° C reduces the residual phosphorus content to 1-4 ppm. The same effect can be frequently achieved by a preliminary desliming with 5% formic acid or citric acid. Deodorization at 210° C of oils that have been deacidified with ammonia and washed with water yields bland and pale edible oils having good keepability.     

Neue Tocopherol-Bestimmungs-Methoden und deren Anwendung bei Pflanzenölen

New Methods for the Tocopherol Determination and Their Application in Vegetable Oils The author checked the methods for the determination of tocopherols in oils and carried out series of experiments to work out modified or new methods which enable the separation of tocopherols and their rapid determination without decomposition. He used the thin-layer chromatography for the separation and developed with the help of the data available in the literature two modified methods for the determination of total tocopherols and the homologous components side by side. In the course of further experiments he eliminated the saponification step which is characteristic for the usual methods and worked out direct methods of determination.     

Über den oxidativen Verderb bei Pflanzenölen

Oxidative Decay of Vegetable Oil The correlations among the parameters: degustation figure, induction period, oxidation velocity and peroxide value of vegetable oils were investigated. The degustation figure, important for the eating quality, could not be predeterminated by the oxidation velocity or the peroxide value. For most of the examined oils, however, the degustation figure could rather safely be predicted after a certain storage period according to the induction time. Vitamine addition of α-tocopherol acetate does not cause any improvement of the stability.     

Untersuchung von Steringemischen V: Die Sterine in Sonnenblumen- und anderen Pflanzenölen

Studies on Sterol Mixtures V: Sterols in Sunflower Oil and Other Plant Oils Sterol mixtures from 21 different plant oils were studied by gas chromatography. Comparison with sterol fractions from seed oils of pure breeding varieties of Helianthus anuus revealed that the quantitative composition is little affected by variety. Furthermore, the variations in fat content, unsaponifiable lipids and in the content and composition of sterol fractions during ripening of the seed were followed. A sterol, which has so far not been reported in sunflower oils, was found and identified as 24-methylene cholesterol.     

Farbe von Ölen

Colour of Oils For many products, particularly edible oils and fats, color is an essential indicator for quality. Today instruments are used to measure the color in oils, fats, fatty acids or other substances. The Tintometer is a subtractive colorimeter, which used red, blue and yellow glass standards. Almost everywhere in the world, the Lovibond color scale is nowadays considered as an accepted means of assigning precise color values to edible oils and fats. But there are also, of course, alternative ways and techniques of determining or measuring color. In recent years, the development of microprocessor-controlled colorimeters has made it possible to automatically measure and compare Lovibond color scale and correlating international standard values pursuant to the CIE System.     

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.     

Vergleich der Vitamin- und Antioxidans-Wirkung der verschiedenen Tocopherole bei den wichtigsten Pflanzenölen

Comparison of Vitamin Activity and Antioxidant Activity of Various Tocopherols from Important Vegetable Oils Unsaponifiables of most vegetable oils contain tocopherols in varying amounts and ratios. All these tocopherols do not have the same action. It is known that vitamin E activity is in the decreasing order for α-, β-, γ- and δ-tocopherols whereas antioxidant activity increases in the same order. Accordingly, an oil which is rich in vitamin E is not necessarily the most stable one. The tocopherols occuring most commonly are α- and γ-tocopherols. Influence of various refining steps on the tocopherol content is discussed briefly.     

Biotische Abbaubarkeit von Rapsölen

Biotic Degradation of Rapeseed Oils Rapeseed oils are increasingly use din fields of application where they enter the environment immediately after use. In this case an assessment of ecological safety is necessary. An important ecotoxicological criterion is the biotic degradation. For testing of water insoluble products only a few standardized CECD-test-guidelines exist. The determined degradation rate obtained by testing according to these guidelines includes only those parts of the product which are used by the microorganisms as energy source. Using the CEC-test the consumption of a test substance by the microorganisms for the gain of biomass and for energy can be determined as biodegradation. The degradability testing of rapeseed oils from different producers according to the CEC-guideline revealed that the product was nearly completely degraded within a period of 7 days.     

Der Einfluß der Raffination auf die Konzentration von Spurenmetallen in Ölen und Fetten

Effect of Refining on the Concentration of Trace Metals in Oils and Fats The published concentrations of trace metals in edible oils and fats vary considerably. This is probably not only caused by samples being of different origin but also by different methods of analysis. Values determined by us for lead and mercury in crude oils and fats are relatively frequently above the limits featuring in German draft legislation dating from May 1974. Refining, as normally done for oils and fats, reduces the lead contents to or below the draft limit of 0.15 ppm. Even after refining the draft limit of 0.025 ppm mercury is sometimes exceeded. The neutralisation step is primarily responsible for the reduction of the lead content.     

Der Weltmarkt der Pflanzenöle,ihre Produktion,Verwendung und Vermarktung

World Market of Vegetable Oils - Their Production, Application and Marketing Oils and fats are raw materials which can be reproduced in a short time. They are therefore important alternatives for the technic, that means for feed industry and oleo chemistry, to the limited fossil resources of the earth. More than 80% of these raw materials are used in human nutrition, only 20% in technic. A world population of 11 mrd people could be nourished by optimization of the agrarian politics and adoption of new technologies as for example the gene technic. Besides, oil and fat raw materials exist which cannot be used for nutrition and are therefore led to a convenient recycling in technic. These products are put on the market in a similar way as the precious metals, foreign exchanges or shares. This stock character means that this market is not only influenced by fundamental factors, but to a very high extent by speculation, too. Especially this actual situation is characterized in a high degree by speculative influences.     

Möglichkeiten der Verwendung von Pflanzenöl als Kraftstoff für Dieselmotoren

Potential of Vegetable Oil as a Fuel for Diesel Engines Vegetable oils seem, not only under agricultural aspects, to be an alternative fuel because of their properties similar to Diesel fuel. For such renewable resources there exists principally an almost closed and also fast CO₂-cycle. For the time being rape oil methyl ester which will not be competitive from the economical point of view in a medium term range is predominantly used in small scale projects. The less expensive raw rape oil can only be used in special Diesel engines which was the result of special investigations carried out on behalf of the Federal Ministry for Research and Technology. There are only small advantages in the emission of air pollutants of vegetable oil engines at the place of operation. Because of the limited availability of vegetable oils there is only a limited potential for the substitution of Diesel fuel. Under long term aspects such bio fuels can contribute, however, to a substitution of the limited crude oil resources.     

Zur Darstellung und Charakterisierung von Vinylsenfölen

Synthesis and Characterisation of Vinylisothiocyanates The preparation of vinylisothiocyanates by treatment of γ-chloroallylchlorides with KSCN followed by rearrangement of the γ-chloroallylthiocyanates is described. The structure is proved by the reaction of the vinylisothiocyanates with mercaptides and by spectroscopic methods.