Detection and determination of Dowtherm A in fatty oils by means of gas chromatography and spectrophotometry have been studied. Gas chromatography of the unsaponifiable materials extracted can be used for determination of Dowtherm A down to the 5 ppm level in 10 g refined soybean oil. Separation of hydrocarbon fraction from the unsaponifiable materials with thin-layer chromatography followed by gas chromatography is useful for the determination of Dowtherm A in fatty oils in concentrations as low as 0.2 ppm. When SE-30 column is used, Dowtherm A indicates two peaks for diphenyl and diphenylether at column temperature 130°C, and a single peak at column temperature above 190°C. Dowtherm A is detected by the retention times and area ratios of diphenyl and diphenylether in the gas chromatography.
In the previous paper, sphingosine-containing lipid was found in acetone-insoluble lipids of Japanese Littleneck, Tapes japonica Deshayes. This sphingolipid was identified as ceramide 2-aminoethylphosphonate.
Fatty acids and fatty alcohols which constitute human skin lipids were investigated by combined GLC-Mass spectrometer using fatty acids (mono basic acids) and fatty alcohols (primary alcohols) occuring in wool fat as standard materials. Free fatty acids and combined fatty acids derived from try-, di-, mono-glycerides, waxes, and sterolesters consist of straight and branched chain fatty acids, of which constituents are n-C12n-C18 fatty acids, C12, C14, C16, C18 iso fatty acids, C12, C15, C17 anteiso fatty acids and highly branched chain fatty acids. Free fatty alcohols and combined fatty alcohols derived from waxes consist of straight and branched chain fatty alcohols, which are n-C14n-C25 fatty alcohols, C16, C18, C20, C22, C24 iso fatty alcohols and C15, C17, C19, C21, C23, C25 anteiso fatty alcohols.
By means of gas chromatography using 0.75% Silicone SE-30 Gas Chrom P, 80100 mesh, glass column and Apiezon L capillary column, hydrocarbons were separated into straight and branched chain hydrocarbons, of which carbonnumber are from C14 to C41 and are mainly C22C31. Waxes were separated into straight and branched chain waxes, of which carbon number are from C24 to C42 and are mainly C36 by 1.5 % Silicone OV-17 Chromosorb W, 6080 mesh, glass column gas chromatography.
It is a well known fact that edible oils are changed in their taste after deep fat frying. However, little research has been made on the taste of frying oil. In order to determine the change of taste of oils by heating, the authors have been carrying out the fractionation of components in heated oil and tried the organoleptic test of each fraction, which was added into original oil. In this investigation, the authors examined the effect of unsaponifiable matter (USM) on the taste of heated oil. Commercial soybean oil was blown with air at 180±3 °C for 48 hours and USM separated from this oil was added to original soybean oil. As the result of the organoleptic judgement of oils added USM from original and heated oils, it was observed that USM separated from heated oily had an effect to the taste of heated oil, and an impression of “blooming” or oxidized odour was detected in the added oil. But any four primary taste could not be recognized. Moreover, the authors found that the most active substance in USM was hydrocarbon. As shown in Table-5, the component of hydrocarbons in heated oil was quite changed as compared with that of original, oil.
The isolation and structural elucidation are reported of a new triterpenoid alcohol from ferulates in rice bran oil. The new alcohol, mp 156.5157.5°C, [α] D+38.4° was assigned the molecular formula C31H52O on the basis of the elementary analysis, molecular weight and mass spectrum, and was named cyclobranol by us. The structure of cyclobranol was deduced 24-methyl-cycloartenol byr the spectral evidence and the retention time of gas chromatography.
The properties of the oils of Polyporus and Auricularia and their compositions of fatty acid and unsaponifiable matter were studied. Those mashrooms were dried and extracted with ether. The oil-contents of the dried bodies were 0.84% (Polyporus) and 1.83% (Auricularia). The properties of the ether-extract were as follows; n20D 1.4667, I.V. 53.9 and unsaponifiable matter 25.6% (Polyporus), n20D 1.4773, I.V. 117.8 and unsaponifiable matter 22.4% (Auricularia). The mixed fatty acids were esterified to methyl esters with methanol and p-toluensulf onic acid. The esters were treated with mercuric acetate, then separated to saturated parts and unsaturated parts through silica gel column developing with benzene. The fatty acid compositions in each part were analyzed by gas chromatography. Acetone insoluble matters were obtained with the yields of 1.83% (Polyporus) and 1.62% (Auricularia). Those compositions coincided with lecithin, lysolecithin (Polyporus) and lecithin, cephalin, and sphingomyelin (Auricularia) on TLC. The unsaponifiable matters both were brown soft-solid. The sterol-percentage in unsaponifiable matters were 27.8% (Polyporus) and 49.3% (Auricularia), and Δ5, 7 sterol-percentage 11.0% and 31.7% respectively. The main sterols of Polyporus and that of Auricularia were considered as ergosterol and 22, 23-dihydroergosterol respectively from similarities of themselves and their acetate regarding to the melting point, UV and IR absorption spectra.