Authers investigated the quantitative determination of stigmasterol in the sterol mixture separated from the rice bran oil by the means of infrared spectrophotometer and gaschromatography. The determination of stigmasterol by infrared absorption agreed nearly with results of gaschromatography in lower values. From the merit in relatively simple operation of the infrared absorption allowing another merit in the identification of substance, the authors believe that the best mean is to compare the result of infrared absorption with that of gaschromatography for a sterol mixture separated from the rice bran oil.
Allyl α-sulfopalmitate can be polymerized in the aqueous medium in the presence of potassium persulfate. The polymerized allyl ester is polyelectrolyte and the aqueous solution of this substance shows structural viscosity. This can be well shown by a rheometer with two concentric cylinders. Since this polymerization reaction was sensitive to oxygen, several factors affecting polymerization, i.e., concentration of initiator and monomer, dissolved oxygen, and polymerization temperature, were investigated. A relation between the rate of polymerization and that of decomposition of initiator, dM/dC (M : monomer, C : initiator), was also estimated and compared with those of the other allyl compounds. The rate of polymerization was measured by sampling the reaction mixture at a definite time interval followed by determination of the iodine number of each sample with modified Wijs method. The rate of decomposition of initiator was measured by ferrous sulfate-ceric sulfate method. The conclusions obtained were as follows : 1. Iodine numbers with modified Wijs mothod, which were measured in the aqueous solution, were approxi-mately in accordance with the results obtained by ordinary Wijs method. 2. The polymerization was largely affected by temperature, for instance, at 70°C it reached to about 90%, whereas at 40°C it was no more than 5%. 3. This polymerization reaction was assumed to be of the second order, and the rate constant was proportional to the concentration of the initiator. 4. The apparent rate constant decreased with the increase of the concentration of the monomer, but the initial rate of polymerization was nearly constant independently from the monomer concentration. The activation energy of the reaction was assumed to be about 36kcal/mol. 5. dM/dC was not constant and increased with the increase of the concentration of initiator, being different from the cases of other allyl compounds. Thus a linear relation between (dM/dC)2C/M2 and dM/dC was no more substantiated, and the former increased rapidly with the increase of the latter.
Authors investigated the determination of cyclopropenoid fatty acid contained in kapok seed oil and could obtain satisfactory result with the following procedure. The sample oil dissolved in benzene-acetic acid was reacted with a 0.1 N solution of hydrogen bromide in acetic acid and the excess of hydrogen bromide was back titrated with 0.1 N solution of sodium carbonate in acetic acid. The content of cyclopropenoid fatty acid in crude kapok seed oils was found usually at 1214%. Both bleaching and deodorization processes tended to decrease the amount of cyclopropenoid fatty acid with increase of conjugated diene. Lager amount of earth used in the bleaching process resulted in the more extensive opening of cyclopropenoid ring. The decrease of cyclopropenoid fatty acid was also followed by infrared spectrophotometry.
Authors investigated the hydrocarbons which were generated in the process of catalytic reduction of fatty ester to obtain higher alcohol under high pressure H2. Methyl palmitate, cetyl alcohol and cetyl acetate were treated under high pressure H2 (initial pressure 100200atm.) in the existence of various kinds of catalysts, such as Cu-Cr-O, Zn-Al-O, Zn-Cr-O, Fe-Al-O, Fe-Cu-Al-O, Fe2O3, reduced Fe, ZnO, Al2O3, CuO, Cr2O3 and Raney Ni (W-7). The amount and the constituent of generated hydrocarbon depended on catalyst used and reaction temperature. In the case of reduced Fe and metal oxides, the generation of hydrocarbon having 16 carbons, considered to be produced by dehydration of the alcohol, was preferential to the generation of hydrocarbon having 15 carbons, considered to be produced by elimination of methylol group from alcohol. The order of its priority was as follows, Fe-Cu-Al-O>ZnO, CuO, reduced Fe, Al2O3>Zn-Cr-O, Fe-Al-O>Cr2O3, Fe2O3>Cu-Cr-O. In the case of Cu-Cr-O catalyst, there was no appreciable difference in the amount of both hydrocarbons generated. On the other hand, in the case of Raney Ni the generation of C15 hydrocarbon was predominant, and the generation of C16 hydrocarbon was almost the same as those of C14 and less carbon number hydrocarbons. In spite of the presence of high pressure H2, the content of olefin in hydrocarbon formed increased in such order as Fe-Al-O<Zn-Al-O<Zn-Cr-O<Cr2O3<ZnO<Al2O3<Fe2O3. At the same reaction temperature, about 300°C, the ease of generation of hydrocarbon was as follows, Raney Ni>Cu-Cr-O>Fe-Cu-Al-O>reduced Fe>Fe-Al-O>Zn-Al-O, ZnO>Cr2O3>CuO>Fe2O3, Zn-Cr-O, Al2O3. The optimum reaction temperature to produce higher alcohol was different by each of the catalyst and the amount of hydrocarbon formed increased in such order as Fe-Al-O>Zn-Al-O>Zn-Cr-O>Cu-Cr-O.
By means of X-ray powder method, the crystals of long-chain n-alkylphosphonic acids, having carbon atoms of 1118, and their monosodium salts were studied. The crystals of the acids were classified into three groups, one of which consisted of odd numbers of carbon and the other two were of even numbers, although the alternation of the melting point with the carbon number was not found. When the acids were treated with the solution of neutral alkali metal salts, such as sodium chloride, the salts were formed which were insoluble in water or in organic solvent. The salts were confirmed as the monosodium salts of the acids by X-ray analysis.
Authors investigated nutritive value of the distillable products which are formed when oils are heated at 300°C. Acidic fraction is as well nutritive as soybean oil while neutral fraction is toxic. As the neutral fraction mainly consists of hydrocarbons, nutritive value of hydrocarbons were investigated. Hydrocarbons having below nine carbons have no nutritive value but not toxic, while those having above ten carbons are toxic to the weanling rats. The limits of toxicity of hydrocarbon was also studied. 1ml of decene to 5g of basal diet caused death of all rats, while addition of 0.25ml of decene could keep life.
The changes of phosphatide components and emulsifying properties in heated soybean phosphatide suspensions are described in this paper. 10 percent soybean phosphatide suspensions were heated at 95°C for 0, 15, 30, 60 and 120 minutes and then freeze-dried. Chemical properties of these samples such as the acetone soluble lipid component and phosphorus of water soluble compounds containing glycerylphosphoryl lipids and glycerophosphoric acid were determined. The contents of individual phosphatides were determined by silicic acid column chromatography as described by Hanahan. The phase inversion curves and emulsion stability were determined as described in the earlier paper. The contents of water soluble compounds and lysophosphatide increased in the heated samples and these phosphatide suspension could easily make O/W type emulsion in system of soybean oil with water and they are more stable than non-heated sample. Emulsifying properties of lysolecithin and glycerylphosphorylcholine prepared from lecithin were determined. Both of lysolecithin and glycerylphosphorylcholine could make O/W type emulsion easily but the former gave a stable emulsion while the emulsion in the latter is unstable.