摘要:

AbstractDurch HPLC‐Chromatographie können Dimerfettsäuren in Form ihrer Methylester in drei Fraktionen getrennt werden [W. Link, G. Spiteller, Fat Sci. Technol.92, 135 (1990)]. Die Hauptfraktion der HPLC‐Trennung der Dimerfettsäuredimethylester aus der Dimerisierung von Linolsäure enthält ungesättigte alicyclische Dimerfettsäuredimethylester mit den Molekulargewichten 588 und 590. Ein Einblick in ihre Strukturen war bisher nicht möglich. Nun gelang durch Hydrierung, Epoxidation und Dehydrierungsexperimente, sowohl mit SeO2als auch mit Pd/C, der Nachweis, daß diese Fraktion von Dimerfettsäuredimethylestern sich hauptsächlich aus Dimerfettsäuren, die neben einem 6‐Ring eine Doppelbindung enthalten, sowie aus Dimerfettsäuren, die zwei 6‐Ringe und eine Doppelbindung aufweisen, zusammensetzt. Die Doppelbindung kann in beiden Verbindungstypen sowohl außerhalb als auch im Ringsystem sein. In Dimerfettsäuren, die zwei Ringe besitzen, können diese sowohl aneinander kondensiert als auch durch eine C‐Kette voneinander getrennt sein. Neben Dimerfettsäuren mit zwei 6‐Ringen konnten Dimerfettsäuren mit einem 6‐Ring und einem 5‐Ring nachgewiesen werden. Wesentliche Beiträge zu dieser Erkenntnis kommen durch Studien an Model

ISSN:0931-5985    

DOI:10.1002/lipi.19940961001

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

摘要:

AbstractComparing the phase diagrams of the three binary soap systems KC16/glycerol, KC16/ethylene glycol and KC16/butylene glycol (KC16= K‐palmitate), we found alterations in types of phase diagrams that depend on the chemical structure of the protic solvent. Variation of the polymorphic transitions were observed. In the binary system KC16/ G (G = Glycerol) we observed the polymorphism: C ↔ G ↔ H ↔ L ↔ S (C = crystalline phase, G = gel phase, H = hexagonal phase, L = lamellar phase, S = isotropic solution). In the binary system KC16/E (E = ethylene glycol) we found the polymorphic transitions: C ↔ G ↔ L ↔ S. In the binary system KC16/B (B = butylene glycol) we observed the same phase sequences: C ↔ G ↔ L ↔ S. So we came to the conclusions that the influence, which the solution medium exerts on the formation of structures in binary systems is distinct and pronounced. Differences in number, position, extension, and in the sequence of the occurring mesophases were found as a function of the composition of mix

ISSN:0931-5985    

DOI:10.1002/lipi.19940961002

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

摘要:

AbstractThrough the ages, a major portion of fats and oils produced by man has been used as human food and animal feed. For little more than a century, most of the inedible fats, together with substantial proportions of edible fats and oils, have served as raw material for the production of bulk commodities such as soaps and detergents, paints and varnishes, as well as lubricants and plastics. These products are beneficial on account of their physical and chemical properties. The biological properties of some naturally occurring lipids are being recognized and appreciated since the 1930ies. As a result of intensive research efforts, the structures of these substances, notably of the fat‐soluble vitamins, hormones, essential fatty acids and oxylipids derived therefrom, pheromones, platelet activating factor and other ether lipids, are now known. Both naturally occurring lipids and semisynthetic or synthetic analogues are being applied in agriculture, bio‐medical research and clinical therapy. A ‘fat tree’ devised in 1958 by the lateH. P. Kaufmannillustrates the wide applicability of fats and oils at that time. The present article includes a figure showing further ramifications ofKaufmann's tree. The structures, properties, and uses of the substances added recently are outlined in a series of publications that appeared in a special issue of the journal Fat Science Tec

ISSN:0931-5985    

DOI:10.1002/lipi.19940961003

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

摘要:

AbstractRape seed oil methyl ester (RME), a diesel fuel substitute and a technical product of increasing importance, contains a number of minor components, which may influence its technical properties in various ways, Sterols, the main constituents of the unsaponifiable matter in rape seed oil, represent an important group of such minor components, which are then found in rape seed oil methyl ester. The concentration and composition of the total sterols in the fraction of unsaponifiables were determined in several RME samples of different origin by the usual procedure of saponification and isolation of the sterol fraction, followed by gas chromatographic analysis. The concentration and composition of the free sterols present in RME and the content of sterol esters were also determined by on‐line LC‐GC. The total sterol content in the RME samples varied between 0.70% and 0.81%. The sterol fraction of RME composed as follows: 0.4% cholesterol, 9.0% brassicasterol, 37.7% campesterol, 0.4% stigmasterol, 48.0% β‐sitosterol, 2.8% Δ5‐avenasterol, and 0.5% Δ7‐stigmasterol. By on‐line LC‐GC 0.24‐0.34% free sterols and 0.55‐0.71% sterol esters have been foun

ISSN:0931-5985    

DOI:10.1002/lipi.19940961004

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

摘要:

AbstractPhulwara butter behaved like a plastic fat without showing any supercooling property, which is mainly due t o presence of trisaturated triacylglycerols. The olein obtained after removal of about 10% harder stearin fraction showed considerable improvement in supercooling property. However, the olein had lower solids content at ambient temperatures, which make it unsuitable for use in chocolate and confectionery. On the other hand, the middle stearin fraction obtained by two‐stage fractionation had sufficient solids content at these temperatures. The middle fraction, when mixed with cocoa butter, depressed the overall melting range of the latter by lowering the solids content at 32.5°C, the effect being more pronounced as the level of the fraction in the mixture increased. At 15% concentration with cocoa butter, the fraction had cooling curve similar to that of cocoa butter. The fraction was found t o have slightly better tolerance towards milk fat compared to that of cocoa butter. The results revealed that the fraction when incorporated into chocolate along with cocoa butter, imparted more cooling sensation in the mouth compared to those prepared with cocoa butter alone. The fraction was found to be suitable to replace part of cocoa butter in chocolate and other confectionery products, where cooling sensation is desirable and finds application in cold climates and also in the preparation of ice‐cream coat

ISSN:0931-5985    

DOI:10.1002/lipi.19940961005

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

摘要:

AbstractBloom was isolated from stored chocolate products for the separation of its triglycerides via high performance liquid chromatography and for the estimation of melting curves by means of thermal analysis. Different types of bloom show specific triglyceride distributions. Bloom on plain chocolates consists of cocoa butter fractions with increased concentrations of POP, POS and SOS, while nut products reveal bloom with high triolein contents. With respect to these results the accelerating effect of nut or almond oils as well as the retarding effect of milk fat may be explained.

ISSN:0931-5985    

DOI:10.1002/lipi.19940961006

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

摘要:

AbstractThe mass spectra of the picolinyl derivatives of two natural occurring cyclopropenoid fatty acids (malvalic and sterculic acid) showed, besides the typical peaks for picolinyl derivatives, a characteristic gap of 66 amu between the two allylic positions of the ring system. This phenomenon could be used for the determination of the ring position of this type of fatty acids.

ISSN:0931-5985    

DOI:10.1002/lipi.19940961007

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

摘要:

AbstractSeeds of some oilplants cultivated in Mongolia (rapeseed, sunflower, soya and mustard) were investigated for oil content and fatty acid composition in dependence of their varieties and cultivation regions. Seeds of given oilplant varieties have nearly same fatty acid composition, but they differ in their oil content. The rapeseed oils do not contain erucic acid, but the seed oil of mustard contained 15.5 % eicosenoic acid.

ISSN:0931-5985    

DOI:10.1002/lipi.19940961008

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY

ISSN:0931-5985    

DOI:10.1002/lipi.19940961009

出版商:WILEY‐VCH Verlag    

年代:1994

数据来源: WILEY