The relationship between the decomposition of peroxide on oxidized oils by heating in an atomosphere of carbon dioxide and carbonyl value (conventional method by 2, 4-dinitrophenylhydrazine) were investigated. 1) Soy bean oil were aerated at 150°, 160° and 170°C for 180 minutes and required samples were heated in an atomosphere of carbon dioxide at respective temperature for equal time as in the case of previous aeration. Their peroxide values were then measured at regular intervals for 30 minutes. The result suggested that, in the thermal oxidation, the quantitative proportion of formation and decomposition of peroxide value existed in a very constant level throughout for 180 minutes at each temperature; i.e., about 45m eq/kg at 150°C, 35m eq/kg at 160°C and 28m eq/kg at 170°C. 2) Oxidized soy been oil (P.O.V. 364), rape seed oil (P.O.V. 262) and lard (P.O.V. 172) were prepared by aeration at 98°C, then they were heated at 60, 98, 150 and 200°C in the atomosphere of carbon dioxide. Almost amounts of peroxide were decomposed fastly (about 20min) at 200°C, but did not decomposed when heated at 60°C for 8 hours. However, when peroxide were concentrated more higher (P.O.V. 600700), decomposition occured but very slowly even at 60°C. During the early stage of peroxide decomposition in each case at 98°C and 150°C, a considerable rates of decomposition were observed, but in the later stage, the rates were slow and usually decreased. Each decomposition at 98°C and 150°C showed closely parallel curve and showed just opposite to the curve of typical induction period in autoxidation. 3) The results of this investigation showed several aspects. a) Although the decomposition of peroxide may occure from such causes as temperature, time and catalysts, the accumulation of peroxide itself is a cause of accelerated decomposition. b) Peroxide formed in the autoxidation interferes to the determination of carbonyl value, but which formed as the result of frying dose not. c) Estimation of carbonyl value may serve as a reliable index of frying deterioration of oils.
Bomer numbers were measured by acetone method with 16 samples of lards obtained from abdomen, rib, back and bone; in these samples, No.1No.12 were obtained from Middle Yorkshire and No.13No.16 from Berkshire breed. 1) Bomer numbers of the abdominal fats were comparatively high and the mean value is 76.41, and were followed by the values of fats from rib, back and bone being 75.83, 74.91 and 74.96 in their mean values respectively. The fats of higher Bomer numbers seemed to afford the larger yield of precipitated glyceride. 2) There were almost no differences between the hog breeds, but Bomer numbers of Middle Yorkshire breeds showed a little higher values. Slight differences in Bomer numbers were recognized between the places of breeding, and the lards obtained from Gumma and Saitama Prefectures showed a little higher values than those from Ibaragi and Kagoshima Prefectures. 3) Six samples showed high Bomer numbers above 77, and the highest value in them is 78.8 which was obtained from No.11 sample of abdominal fat. The glyceride precipitated from this sample contained about 15% of mono-unsaturated glyceride and about 24% of stearodipalmitin which was calculated from the content of palmitic acid. Accordingly, it is considered that the difference between the melting point of the precipitated glyceride and that of the mixed fatty acids had increased.
Analyses of α-sulfofatty acids may generally be performed by sulfur-determination, S-benzylthi-uronium salt method, chelatometric method, pH titration, semi-micro methylene blue backtitration method (M.B. method) and photometry. Particularly, α-sulfofatty acid in a reaction mixture, which is contaminated with unreacted sulfur trioxide, fatty acid and carbon tetrachloride can be determined by only two methods, the M.B. method and photometry. In this paper, the results of the pH titration applied to the analysis of α-sulfofatty acid were described, and newly developed photometric method was compared with the M.B. method. α-Sulfopalmitic acid was precipitated as copper salt in the aqueous medium, and the copper ion remaining in the solution was determined photometrically. Then the α-sulfopalmitic acid in the sample was calculated. The results of the proposed and the M.B. methods showed good agreement. It has been found that the proposed method was applicable to the determination of the other surface active agents.α-Sulfofatty acid reacted with copper sulfate in the mole ratio of 2 : 1.
Soybean oil was oxidized at 110°C until strong rancid flavor developed, and was distilled at 80°C under 0.050.1mmHg. The volatile flavor components were condensed in a trap cooled with liquid nitrogen and were extracted from trap contents with a few drops of ethyl ether. The flavor concentrate was separated with 10% Na2CO3, Girard's T reagent into three fractions, namely, acid, carbonyl and other compounds (named non-carbonyl), respectively. Each fraction was fractionated by gas chromatography. Isolated compounds were classified by quality test using mercuric acetate, silver oxide and 3-nitro-phthalic anhydride, using at least two stationary phases. Several of them were further verified by infrared spectroscopy. In carbonyl and acid fraction the following compounds were characterized; C2, C5C9n-alkanal, C4C9 2-alkenal, C7, C10 2, 4-dienal, C2C6n-saturated fatty acid, and C3C5 unsaturated fatty acid. The noncarbonyl fraction was mainly composed of saturated and unsaturated alcohols, and pent-1-en-3-ol, n-amyl alcohol and oct-1-en-3-ol were identified.
Polypropyleneglycols of the lower molecular weights are easily soluble in water, but they become progressively less soluble with increase in the propyleneoxide units. The molecular weights of the polypropyleneglycols showing any remarkable solubility in water are limited up to about 2000 and the polypropyleneglycols of these molecular weight ranges show very high surface activities. They were tested by measurement of surface tension, wetting, and dye-dispersing power, etc., and it was shown that polypropyleneglycols of molecular weight of about 2000 have the most high surface activity and strong dye-dispersing effect. It is noted that polypropyleneglycols entirely consisting of the repeated propyleneoxide structural units show the surface activity, while molecules of most typical surface active agents generally known have the typical hydrophobic and hydrophilic parts.
Four ethylene glycol di-fatty acid esters (A) and four ethylene glycol mono-fatty acid esters (B), prepared from ethylene glycol and butyric, caprylic, lauric and palmitic acid, were pyrolyzed at 200750°C in nitrogen atmosphere. The products of pyrolysis of the former (A) were fatty acids and fatty acid vinyl esters and a small amount of lower fatty acids and ketones, and those of the latter (B) were fatty acids and acetaldehyde and a small amount of fatty acid vinyl esters, lower fatty acids and ketones.
In addition to the products previously reported, o- and p-lauroylphenol and laurone were isolated from the reaction product of phenol with lauric acid in the presence of the Japanese acid clay. The experimental conditions were as follows; the mole ratio of phenol to lauric acid=4/1, the amount of the clay added=10% by weight to the total organic reagent, the reaction temperature 190°C, the reaction time 2 hours. Laurone was obtained in 40% yield (theo.), when the clay preheated at 110115°C for 1.5 hour was used.
Quantities of dissolution residue of cupric oxide powder in dilute sulfuric acid after definite minutes at the presence of specified surfactants were measured. As the surfactants used, several anionic, cationic and nonionic surface active agents as well as sodium hexametaphosphate and tripolyphosphate were used. The results were as follows : When surfactants were used individually, sodium hexametaphosphate, tripolyphosphate, dialkyl-dithiophosphate, Ca-lignosulfonate and Ca-creosote-tamol were excellent as inhibitors of acid corrosion, while lignosulfonate or di-naphthylmethanedisulfonate homologue with hexametaphosphate was most excellent among combinations of surfactants mentioned above.