Studies on the constituents of sterols, 4α-methylsterols, and triterpene alcohols in a number of vegetable oils have led to the identification and characterization of one twenty-eight compounds in all (fifty-six of sterols, thirty-one of 4α-methylsterols, and forty-one of triterpene alcohols) which included a number of compounds detected for the first time in higher plants, in addition to twenty-eight new or newly found natural products. The occurrence and distribution of these compounds in vegetable oils were extensively investigated. In addition to these, the characterization of sterols and triterpene alcohols has been studied with the aid of gas chromatography, especially on glass capillary columns, and nuclear magnetic resonance (NMR) spectroscopy. The determination of the stereochemistry at C-24 of a large number of 24-alkylated sterols, 4α-methylsterols, and tetracyclic triterpene alcohols was performed with high-resolution 1H-NMR and 13C-NMR spectroscopy.
In previous papers, the authors, members of the Fat Stability Committee of Japan Oil Chemists' Society, reported the results of fat stability tests on autoxidation. The present paper presents the results of collavorative tests on fat thermal oxidative stability. Oils were heated at 180°C or 200°C in an AOM Test Tube. Carbonyl, anisidine and acid values and viscosity of the heated oils were measured. The carbonyl value (fresh soybean oil, about 2) increased linearly to about 15 after 10h heating at 200°C. That of anisidine value (fresh corn oil, about 5) increased to about 180 after 20h of heating at 200°C. The acid value and viscosity of the heated oils (10 or 20h heating at 180 or 200°C) increased only slightly.
The quantitative estimation of isomeric monoacylglycerol (MG) content in edible fatty oils was carried out by boric acid-impregnated rod TLC-FID using MG concentrates as samples. The MG concentrates were prepared by extraction with CH3CN from an edible oil-hexane solution. The procedure for CH3CN evaporation to recover the MG concentrates below 30°C hardly brought about any change in the content of 2-MG in the total 1-MG. Five species of refined vegetable oils showed 0.0050.01% for MG content, 9097% for 1-MG/total MG. GC analyses of methyl esters obtained from 1- and 2-MG fractions gave the acyl group composition in each fraction.
A series of linear all-ortho alkylphenol-formaldehyde novolak resins were prepared by reaction of bromomagnesium alkylphenoxide with paraformaldehyde in benzene. The alkylphenols were p-nonylphenol, p-amylphenol, p-tert-octylphenol, p-tert-butylphenol, m-tert-butylphenol, p-sec-butylphenol, p-ethylphenol, m-ethylphenol, 3, 4-xylenol, 3, 5-xylenol, p-cresol, m-cresol, p-methoxyphenol, m-methoxyphenol, and phenol. The antioxidant effects of these oligomers on the autoxidation of lard were examined by oven tests at 60°C. The oligomers of phenols linked with all ortho methylene-bridges showed good antioxidant effects comparable to those of BHT. Both the substituents on the aromatic rings and molecular weights of the oligomers determined the strength of these effects. Phenolic oligomers having methoxyl groups at the para positions showed excellent antioxidant effects. The most effective molecular weights for these oligomers ranged from about 6001, 000. The antioxidant effects of oligomeric phenolic compounds appeared to arise from cooperative intra-molecular OH-OH hydrogen bonding from adjacent aromatic hydroxyl groups along the chain.
Lauric, myristic, palmitic, and stearic acids were oxidized with an ozone-oxygen mixture (fatty acid : ozone, 1 : 3 mol) at 90°C in acetic acid-water (9 : 1 vol/vol). Fatty acid conversion ranged from 80 to 95%, increasing in the order of stearic, palmitic, myristic and lauric acid. Most of the products consisted of dicarboxylic acid, as a major product but mono- and oxocarboxylic acids were also formed. Dicarboxylic acid (CnH2n-2O4) produced from lauric acid was n=310 and from myristic, palmitic, and stearic acid, n=312. The mono- and dicarboxylic acids formed in large amounts were mainly those having the half numbers of carbon atoms of starting fatty acids. In the reactions, oxocarboxylic acid was initially formed in large quantities but decreased with time, while the amount of dicarboxylic acid increased. The following processes were noted to occur during the course of the reactions : 1) Oxidation of a carbon atom located about center of hydrocarbon chain of the fatty acid to form oxocarboxylic acid. 2) The oxidative cleavage of this acid to form mono- and dicaboxylic acid.
The adsorption behavior of 5 Azo oil dyes and sodium dodecyl sulfate (SDS) at n-dodecane/water interface were studied. In the case of surfactant free systems, interfacial tension decreased with increasing hydrophilicity of the dye. By applying the Gibbs adsorption equation to the interfacial tension data, the interfacial excesses of Azo oil dyes and SDS were evaluated. The interfacial densities and orientation angles of the dyes at the interface were dependent on the type and replacement positions of the hydrophilic groups. In the presence of a surfactant, both the dye and a strongly hydrophilic group interacted with SDS to a considerable extent. The distribution coefficients of the dyes in n-dodecane and sodium dodecyl sulfate micelle solutions were larger for dyes containing strongly hydrophilic groups than those with weakly hydrophilic groups.
The seeds of five varieties of Japanese grape, Koshu, Semillon, Cabernet Sauvignon, Muscat Bailey A, Delaware, were investigated for oil content and characteristics. The crude oil content were 13.2, 14.4, 15.3, 12.7 and 15.1% for these five varieties, respectively. The predominant fatty acid component was linoleic acid in all varieties. Linoleic acid content ranged from 51.671.9%. The total unsaturated fatty acid levels were from 82.2 to 89.4%. The major component of 4-desmethylsterol was sitosterol. The fatty acid compositions and physical and chemical characteristics of the seed oils in these grapes were simillar to those found in safflower and sunflower seed oils.