Freie und gebundene Sterine in rohen und raffinierten Palmölen,Teil II: Sterinhaltige Lipoproteine

Free and Bound Sterols in Raw and Refined Palm Oils, Part II: Sterol Containing Lipoproteins Twelve lipid fractions were isolated from raw palm oil which contain beside sterols, fatty acids and pigments also low amounts of phospholipids and proteins. The very stable complexes can only be decomposed by acid hydrolysis. The composition of sterols and fatty acids in the hydrolysate and the phosphor and nitrogen content in the purified lipid fractions were determined. According to composition and chemical behaviour of these lipid complexes they are sterol containing lipoproteins with strong lipophilic character. In some of these fractions the extremely high cholesterol content is striking which is partly more than 50% of the total sterols. The release of sterols from these complexes during refining might be the reason for the high cholesterol content in some refined palm oils.     

Freie und gebundene Sterine in rohen und raffinierten Palmölen,Teil I: Gehalt und Zusammensetzung der freien Sterine,Sterinester, freien und acylierten Steringlucoside

Free and Bound Sterols in Raw and Refined Palm Oil, Part I: Content and Composition of Sterols, Sterol Esters, Free and Acylated Sterol Glucosides A method for separation and quantitative determination of free sterols, sterol esters, free and acylated sterol glucosides in fats was developed and applied to the investigation of raw and refined palm oil. During refining the content and the composition of all 4 sterol fractions are varying characteristically. Some samples showed an evident increase of the cholesterol level during certain refining steps. Since none of the 4 investigated sterol fractions has such a high cholesterol level, sterols must be present in bound form, which can be liberated during refining and can be determined afterwards by conventional test methods.     

Freie und gebundene Sterine in rohen und raffinierten Palmölen,Teil III: Verhalten der sterinhaltigen Lipoproteine bei der Raffination

Free and Bound Sterols in Raw and Refined Palm Oils, Part III: Behaviour of Sterol Containing Lipoproteins during Refining Studies have been carried out about the behaviour of sterol containing lipoproteins during refining. By neutralization and bleaching they are partly separated together with the free fatty acids. One part, however, is splitted mainly during deodorization. Thus content and composition of lipoproteins are changed during refining. The sterols released from lipoproteins are determined together with free sterols. Because of their high cholesterol content increased cholesterol values can be found in sterol determination of refined palm oils.     

Hauptkomponenten der 4-Methylsterin- und Triterpenfraktion von 12 Pflanzenfetten und ihr Einfluß auf die Sterinanalyse

Main Components of 4-Methyl-Sterol and Triterpene-Fraction of Twelve Vegetable Fats and their Influence on the Sterol Analysis 4-methylsterols and triterpenes are accompanying substances of the sterols in the unsaponifiable with partly very similar chromatographic properties. In 12 different vegetable fats both content and composition of the main components of these three substance groups were investigated and their influence on the sterol analysis was found out. For most fats a thin-layer chromatographic separation of the 4-methyl-sterols and triterpenes from the sterols is necessary to make possible an exact determination of the sterol content and the sterol composition by gas chromatography.     

Schnellmethode zur Isolierung der Sterine aus Fetten und Ölen

Rapid Method for Isolation of Sterols from Fats and Oils Isolation of sterols from fats and oils mostly takes place by the very time-consuming solvent extraction of the unsaponifiable from the soap solution. The time required can be reduced to about 1 hour by a new developed procedure which makes possible to separate soaps and polar components of the fats from the saponified sample by aluminium oxide columns. The use of 250 mg of fat is sufficient for a following sterol examination by gas chromatography.     

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.     

Neuere Untersuchungen der nicht-glyceridischen Bestandteile von Pflanzenfetten

Recent Studies on the Non-Glyceridic Constituents of Vegetable Fats The authors give a comprehensive review on the non-glyceridic constituents of numerous vegetable fats with special reference to the research work in “Stazione Sperimentale per le Industrie degli Oli e dei Grassi” since about 15 years. Initially, the research was concentrated on olive oil, owing to its great economic significance for Italy and other mediterranean countries; later on, the studies were extended to other vegetable oils. A large number of substance classes were found and identified, which include aliphatic and aromatic hydrocarbons, aliphatic alcohols, terpenic alcohols and their esters, sterols and their esters as well as methyl sterols. Exact identification of these minor constituents required development of special techniques for separation, detection and identification, which are discussed individually. Furthermore, substances occurring in the olive are reported, which attract or repel the olive fly (dacus olivae). Some of these substances have odour and taste, such as aldehydes, aliphatic esters, hydrocarbons and furans, whose structures were elucidated by mass spectrometry. This work might be of interest with respect to measures for pest control.     

Identifizierung der Sterine in verschiedenen Lipidgemischen von Schweinen

Identification of Sterols in Various Mixtures of Lipids of Swines The sterol composition of lipid mixtures of blood serum, adrenals, intestinal fat, and back fat of swines was studied. The main sterol is cholesterol, which constitutes 97-99% of the mixture. The remaining sterols, which occur in amounts less than 0.1%, were identified by thin-layer chromatography and gas chromatography on 4 different columns of varying polarity. These are mainly intermediates in the biosynthesis of cholesterol, namely, Δ7-cholestenol, desmosterol, 4-methylchole-sterol, 4-methyl-Δ8(9)-cholestenol, 4,4-dimethylcholesterol, 4,4-dimethyl-Δ8(9)-cholestenol, lanosterol, and dihydrolanosterol. A further sterol with a Δ5,7 double bond, presumably Δ5,7-cholestadien-3β-ol, was recognized from its characteristic UV-absorption. Cholestanol was also present in all samples. Plant sterols could not be detected in the sterol mixtures. Oxidation products of cholesterol, such as Δ4-cholesten-3-on, 7-hydroxy-cholesterol, 7-ketocholesterol, and Δ3,5-cholestadien-7-on were identified. Δ4-Cholesten-3-on is probably formed in vivo, while the others are formed by oxidation of cholesterol during isolation of the sterols.     

Über die Veränderung der Sterine in Fetten und Ölen bei der industriellen Bearbeitung derselben I

Changes in Sterols During the Industrial Processing of Fats and Oils I The investigations of the authors have shown that 7-hydroxy sterols are formed when soybean oil containing sterols is heated in the presence of oxygen. Hydrocarbons and disteryl ethers are formed by bleaching earth treatment of cholesterol, β-sitosterol, stigmasterol and brassicasterol. Treatment of 7-hydroxy sterol with bleaching earth leads to the formation of hydrocarbons and keto-steroids. The sterols are partly oxidized during deodorization under inadequate vacuum. Freshly extracted rapeseed oil does not contain any disteryl ether. However, these substances could be detected in commercial fat samples. In experiments on rats, no carcinogenic properties of dicholesteryl ether could be found.     

Über die Veränderung der Sterine in Fetten und Ölen bei der industriellen Bearbeitung derselben II

Alteration of Sterols in Fats and Oils During the Industrial Processing Nonpolar steroids are formed by the action of bleaching earth on cholesterol, β-sitosterol, stigmasterol and brassicasterol in the presence of hexane. The hydrocarbons formed were isolated and investigated by column chromatography and preparative thin-layer chromatography. The hydrocarbons formed by the action of activated bleaching earth on cholesterol were repeatedly crystallized from ethyl alcohol and identified as Δ^3,5-cholestadiene.     

Über das Vorkommen von 3,4-Benzpyren neben anderen polycyclischen aromatischen Kohlenwasserstoffen in Pflanzenfetten

Occurrence of 3,4-Benzpyrine Amongst other Polycyclic Aromatic Hydrocarbons in Vegetable Fats Besides 3,4-benzpyrine a few other polycyclic aromatic hydrocarbons have been detected and quantitatively determined in raw vegetable oils. These polyaromatic compounds are partly removed during refining of oils.     

Veränderung der Sterine durch industrielle Verarbeitungsprozesse von Fetten und Ölen I: Einfluß der Raffinationsbedingungen auf den Steringehalt und die Sterinzusammensetzung

Alteration of Sterols by Industrial Processing of Fats and Oils I: Influence of Refining Conditions on the Sterol Content and Sterol Composition Action of bleaching earths on cholesterol was studied, both as solution in a neutral synthetic triglyceride and in hexan. The influence of reaction conditions on the amount and qualitative composition of the derivatives formed was investigated. The acidity of both the bleaching earth and the substrate are significant for the reaction. Furthermore, the type and amount of steryl esters as well as the concentration of bleaching earth and sterol in the fat play a role. By gas chromatography and thin-layer chromatography of the sterol derivatives formed it was found that the artefacts formed are qualitatively always the same although their proportions vary.     

Die Untersuchung von Steringemischen III: Quantitative Bestimmung dünnschicht-chromatographisch getrennter Sterine

Investigation of Sterol Mixtures III: Quantitative Determination of Sterols Separated by Thin-Layer Chromatography A new method has been developed for the quantitative determination of sterols. This method is based on thin-layer chromatographic separation of the mixtures after their esterification with 3,5-dinitrobenzoic acid. Subsequently, the individual components are eluted and determined colorimetrically at 525 nm after their conversion to Meisenheimer-adducts using 1,3-diaminopropane in the presence of dimethyl form-amide. The method has been tested with pure sterols and their model mixtures, and has been applied to the quantitative analysis of natural mixtures of sterols from vegetable oils.     

Die Sterine im Aufgußöl von Fischkonserven

Sterols in the Oil Employed in Canned Fish Sterols contained in spices of the sauce get dissolved in the oil used in canned fish upto a point where equilibrium is reached. Concentration of sterols originating from spices was found to be maximum in the sauce of herring filet that had been canned without the addition of any oil. The relative proportion of sterols from spices in the total sterols, that includes sterols which are already present in the oil, decreases with increasing amount of oil used for canning.     

Untersuchung von Steringemischen IV: Das Retentionsverhalten freier Sterine bei der Gas-Chromatographie

Studies on Sterol Mixtures IV: Retention Behaviour of Free Sterols in Gas Chromatography Retention behaviour of a number of free sterols was studied by gas chromatography using SE-30, UCCW-982, OV-17 and OV-25 as stationary phases. In a similar manner as tested for steryl acetates, the separation factors were determined for sterol pairs which differ by one constitutional characteristic. The efficiency of separation of the stationary phases OV-17 and OV-25 were found to be distinctly superior to those of less polar phases. Sterols having Δ²⁴(²⁵)-double bonds are especially well separated from their saturated counterparts. Steryl acetates exhibit on all four stationary phases longer retention times compared to free sterols whereas the trimethylsilyl ether derivatives show on SE-30 and UCCW-982 columns longer and in OV-17 and OV-25 columns greatly reduced retention times.     

Veränderung der Sterine durch industrielle Verarbeitungsprozesse von Fetten und Ölen II: Veränderungsprodukte bei der Behandlung von Cholesterin mit Bleicherden

Alteration of Sterols by Industrial Processing of Fats and Oils II: Alteration Products Formed by Treatment of Cholesterol with Bleaching Earths A part of the derivatives formed by the action of Tonsil on cholesterol could be isolated by preparative thin-layer chromatography and identified using synthetic standards. Depending upon experimental conditions, various amounts of dicholesteryl ether, Δ3,5-cholestadiene, isomeric cholestenes (mainly Δ2-cholestene) and Δ2,4,6-cholestatriene were formed. Disteroids were formed under extreme experimental conditions. Small amounts of oxidized sterols are formed from non-polar sterol derivatives by a subsequent reaction. Chromatographic properties of these substances were studied, in order to find their eventual interference in the analysis of sterols.