Acetone method was compared with ether method in measuring Bömer numbers of pure lard and lard mixtures with beef tallow or horse fat, and was also discussed about its after treatment. In case of ether method, the direct washing of precipitated glyceride by ether was tried as a simlpe and convenient method. In this modified method, 50g of sample fat in a cylinder was agitated with 200ml of ether at 15°C for 1hr, and its precipitate separated was shaken with 50ml of ether at 15°C and was filtered. After that, the precipitate was washed 3 times with each 50ml of ether at 15°C. 1) Both melting points of glyceride (Sg) and fatty acid (Sf) showed higher in the ether method. Consequently, the mean values of Bomer numbers were also higher by 0.25 with abdominal fat and by 0.56 with back fat in the ether method. Precence of another animal fat gave larger difference in the Bomer number than that of pure lard, and the difference of lard mixture containing 20% of beef fat was very remarkable, being 1.12 of its difference. When the content of another animal fat was 40%, the difference came to be smaller, and the same tendency was observed in lard mixtures containing 20% or 40% of horse fat. 2) The crystals of glyceride precipitated from acetone consist of coarse granules while those from ether is extremely fine. In the latter case, the iodine value come to be low since the crystals are washed thoroughly, and the standard deviations (σ) of the measured values are very smaller. 3) Time required for the measurement is far more faster in the ether method, but when a larger amount of glyceride is precipitated, its washing came to be difficult. 4) When recrystallization is repeated in the acetone method, unsaturated glycerides are removed, and the values of (Sg) and (Sf) become higher but the difference of melting point (Sg-Sf) becomes smaller, and the Bomer number come to be low. If recrystallization is repeated twice, the Bomer number becomes slightly higher, but the value is lower than that from ether method. The standard deviations of the measured values come to be very samll by recrystallization.
Several methods for the quantitative analysis of phospholipids in commercial soybean lecithin ware compared. Analytical methods examined were as follows; Hanahan method based on silicic acid column chromatography, Hübscher-method which involves mild alkaline hydrolysis of total phospholipids and extraction of the resulting water-soluble esters and separation of the latter on ionexchange resins using sodium tetraborate-ammonium formate system for the elution, and Dawson-method based on the examination of phospholipid fractions by paper chromatography after mild alkaline hydrolysis. Among them, Hübschers-method was found, best in the determination of main phosphatide components. Quantitative determination of individual phospholipids by Hübscher-method in several lots of commercial soybean lecithin showed that there was little difference except the lot stoked over summer season in which the components of phosphatidylcholine and phosphatidylserine were less than others. In the lots of summer season stock, the package condition (can or paper bag) of soybean affected their phosphatide components. Can stock sample was less changed in the phosphatides and aceton insoluble lipids in the can stock soybean were more extracted than in the paper bag.
α-Sulfonated fatty acids are easily prepared by dropping liquid sulfur trioxide into the solution of fatty acids in carbon tetrachloride. In this process, however, the color of the reaction mixture becomes gradually dark brown and finally black. Thus, repeated washing by a solvent (e.g. petroleum benzine) and recrystallization from it are necessary to obtain white powder, and consequently the yield considerably reduces. The authors tried to use an adduct of dioxane and sulfur trioxide as sulfonating agent to prevent the coloring of the reaction mixture. In this work, α-sulfonation of palmitic acid dissolved in carbon tetrachloride was carried out with three alternative methods, direct method, adduct method and mixed solvent method, and these results were compared and discussed. In each method, 1.2, 1.4 and 1.6 moles of sulfur trioxide were used per mole of palmitic acid, respectively. The samples were taken from the reaction mixture at a definite time interval, followed by measuring the color of each sample by photoelectric colorimeter and the yield of α-sulfopalmitic acid was determined by semimicro methylene blue backtitration method. The conclusions obtained were as follows : 1. Adduct method gave extraordinary low coloring and the conversion of palmitic acid to its sulfoacid was almost 95% or more. Direct method gave markedly high coloring, and the coloring increased considerably after the conversion reached 80%. Mixed solvent method gave moderate coloring. 2. When the mole ratio of sulfur trioxide vs. palmitic acid increased in the order of 1.2, 1.4 and 1.6, the conversion increased in the same order at any time, but the difference of the conversion almost disappeared after about 2 hours from the beginning of the reaction. 3. This sulfonation reaction was assumed to be of the first order from the data of direct method performed at constant temperature, 30°C, 40°C, 50°C and 60°C.
The reaction of dioctanoyl peroxide with carbontetrabromide in the presence of nitrogen gas was studied. Dioctanoyl peroxide was synthesized from octanoylchloride and hydrogen peroxide in ether at low temperature. Carbontetrabromide was prepared from sodium hydroxide, bromine and acetone. The yield of 1-heptyl bromide was 83.4% at optimum condition (carbontetrabromide-dioctanoyl peroxide mole ratio 2, concentration of dioctanoyl peroxide in benzene 1mol%, reaction temperature 70°C, reaction time 24hr). By-products of the reaction were tetradecane, caprylic acid and heptyl caprylate.
The developments of a red colour in frying oils during high temperature are practically important having close relations with the foarming tendencies. In this report, soybean oils were used as the representative of frying oils, and their chromaticy changes when heated were measured by the three methods; Lovibond method, RGB chromaticy method and XYZ chromaticy method. Among them, XYZ chromaticy method was the best to analyse the chromaticy changes indicating the highest sensibility. Then the highly coloured soybean oils were reduced with sodium borohydride, lithium alminium hydride and hydrazine hydrate, and by determining the characteristics and infrared spectra, carbonyl groups and epoxy groups were found to partake the developments of a red colour.Then the reduced material by the use of sodium borohydride was treated with marcuric acetate for addition and the infrared spectroscopic analysis of this material showed that the carbonyl groups having close relations with the red colour development seemed to be α, β- and α, α'-unsaturated carbonyls.
It is known that surface active agents (surfactants) react with protein to liberate thiol group. In this paper, the thiol-group of egg albumin liberated by various sodium soaps were estimated by the thiochrome method. It was found that C12-C14 soaps indicated the most eminent activities for the liberation of thiol group in protein. These findings were quite similar to description of other publications. The data suggest that the liberated thiol groups may be comparable to the irritating action. Furthermore, the pH dependence of thiol-group liberation and the effects of other anionic surfactants were described.
In order to determine Na2CO3 and NaHCO3 in the detergent powder, hydrochloric acid was added to the two detergent samples, one of which was previously heated at 160°C, and the others was not heated. CO2 liberated was absorbed in the N/10-KOH solution, and K2CO3 formed was determined by titration with N/2-HCl solution. The contents of Na2CO3 and NaHCO3 in the detergent sample were calculated from the difference of titration values and almost satisfactory results were obtained.