Heating differential thermal analyses were carried out, as previously reported, on four kinds of coconut oil and four kinds of palm kernel oil of different degree of hardening, comparing variation in the curve by the degree of hardening with the open capillary melting point and polymorphism measurment. 1) Coconut oil stored at 0°C only showed a large and sharp endothermic peak at 24°C, irrespective of the degree of hardening and duration of standing. When coconut oil was left at 20°C for 1 hour, a small endothermic peak appeared at 19°C besides the peak at 24°C, and the smaller peak became sharp with lapse of time of standing. 2) Coconut oil stored at 20°C for 1, 440 hours (two months) showed further changes in the curve, the peaks becoming more complex as the degree of hardening advanced, unhardened coconut oil #8 (I.V. 8.0) and #5 (I.V. 4.9) showing three peaks, #2 (I.V. 2.2) four peaks, and #0 (I.V. 0.7) five peaks. Polymorphism was a β′ type, which did not change greatly with difference in the degree of hardening, period or temperature of standing, but was different in the open capillary melting point. These facts agree with the result of DTA. 3) The DTA curve of palm kernel oil showed greater variation than that of coconut oil, and the curves of #5 (I.V. 5.0) and #0 (I.V. 0.6) showed considerable change after ;standing at 0°C. When stored at 20°C for 1 hour, the curve was the same as that of coconut oil. The variation was greater, the longer the period of standing and higher the degree of hardening. Polymorphism of palm kernel oil was also similar to that of coconut oil, the transition being late, and there was no difference according to the temperature of standing, but showed considerable difference in the open capillary melting point, which was contrasted with the result of a marked difference in DTA curves.
The ferulates from rice bran oil consist of esters of a few kind of alcohols and ferulic acid and these ferulates were saponified in alkali solution, but there recognized a relation between saponification rates and the structures of the alcohols. The saponification rates increase in the following serial order : campesteryl ferulate > β-sitosteryl ferulate > cycloaltenyl ferulate > 24-methylenecycloartanyl ferulate>cyclobranyl f erulate. Furthermore, it was confirmed that digitonides of cycloartenol, 24-methylenecycloartanol and cyclobranol were formed. The formation rates of digitonides of these triterpenoides were lower than those of sterols.
The samples used for this experiment were liquid soybean oil (I. V. 136.2) mixed with fully hardened soybean oil (I.V. 0.4) or fully hardened beef tallow (I.V. 0.3) by 10, 20, 40, 60 or 80%, The open capillary melting point was measured, as in the previous work, after standing at 0°, 10°, 20°, 40° or 50°C for 1, 5, 24, 120 and 1, 440 hr (2 months). At the same time, its correlation to polymorphism was examined, and the softening point (ring-ball type), Wiley melting point and slipping point were also investigated. 1) The open capillary melting point showed a great difference according to the temperature of standing when mixed with 10 or 20% of fully hardened oil, but the difference became smaller withincrease in the amount of hardened oil present. 2) The sample mixed with hardened soybean oil showed rapid transition, all becoming β-type after lhr, and there was no difference by the time and temperature of standing. Samples mixed with 1040% of hardened beef tallow became β-type in 1 hr, and were β′-3 type with 6080% mixture, : showing far more rapid transition than the solitary hardened beef tallow. 3) In all the samples, presence of a large amount of liquid oil resulted in indistinct pattern in X-ray diffraction because of the segregation. Since there was a difference in the melting point by the temperature of standing in spite of the absence of difference in polymorphism it was considered that in such a mixture of oppositely different substances progress of crystallization resulted in segregation, with separation of the solid and liquid parts, and the difference of crystal growth in the solid portion created a difference in the melting point. 4) Both the Wiley melting point and slipping point were higher than the open capillary melting point, and the difference was greater with increase in the amount of liquid oil present. In contrast, the softening point became lower with increase in the amount of liquid oil, but became higher than the open capillary melting point with increase in the amount of hardened oil and there was no definite correlation between them. 5) In general, the lower the temperature of standing and the greater the amount of liquid oil present the measured values became scattered. The scattering of the measured values became greater in the order of the Wiley melting point, softening point and open capillary melting point.
Several works have been reported of the concentration of oleyl oleate from sperm oil. But the oleate oleyl concentrated from sperm oil is so unstable due to the presence of highly unsaturated components that the application of oleyl oleate is limited. It is therefore, necessary to reduce these highly unsaturated components in the oleyl oleate concentrate. The authors attempted to decrease the amounts of polyunsaturated components in sperm body oil by two procedures. The one was to thermally polymerize sperm oil in the presence of active earth, and the other was to hydrogenate the oil selectively with Cu-Cr catalyst under atmospheric pressure. The oleyl oleate was concentrated from thus treated sperm body oils and untreated oil through molecular distillation and fractional crystallization. A.O.M. stabilities of these oleyl oleate concentrates were determined according to the A.O.C.S. analytical method. The oleyl oleate concentrate obtained from thermally polymerized sperm body oil was most stable, while the oleyl oleate from untreated sperm oil was unstable most.
The structure of commercial transparent and translucent soaps have been investigated by means of X-ray diffraction, with the following results. 1) The structure of commercial transparent soap is not completely amorphous, but is believed to consist essentially of rather finer crystalline structure than ordinary opaque soaps.
The influence of metallic ions (Fe (II), Fe (TII), Cu (II)) and the effect of antioxidants and chelating agents on the dissolved oxygen in O/W type emulsion was in vestigated by employing Beckman Oxygen Analyzer Model 777. Vegetable oils with different P.O.V. and water were emulsified into O/W type emulsion using Tween-40, and the absorption of dissolved oxygen was investigated under the presence of Fe (II), Fe (III), and Cu (II) ions. Then citric and tartaric acids as chelating agents, and PG and BHA as antioxidants were added and their influence were investigated. The result showed that the oxygen absorption increases in the order of Fe (II) >> Fe (III) > Cu (II) and this effect was suppressed by the addition of PG and BHA. Chelating agents also showed their effects for low P.O.V. samples, but the effect was not observed for Fe (II) ion for high P.O.V. samples.
In the alcoholysis reaction of fatty oils with pentaerythritol, the effects of reaction conditions on the reaction rate and the composition of reaction products were investigated and the reaction mechanism was discussed. Reaction products consist of glycerol, pentaerythritol, and their esters as shown Fig.-1 These compounds were clearly separated by means of the thin layer chromatography, using silica gel as absorbent and diethylether as solvent. The composition of reaction products was determined by the measurement of the concentration of spots using densitometer. The effects of reaction conditions on the reaction rate were investigated and the following results were obtained. 1) In the system of soybean oil-pentaerythritol, the apparent activation energy of this reaction was about 27 kcal/mole. 2) Reaction rate constants in various fatty oils were in the order of linseed oil > olive oil _??_ coconut oil _??_ dehydrated castor oil > soybean oil, and the apparent activation energies were opposite to this order. 3) Lead oleate was most active among the various catalysts tested and litharge (PbO) was the second. The order of catalytic activity in metal oleates was as follows. Pb >> Ca > Zn _??_ Mn > Li _??_ K > Fe Reaction was obviously the second-order reaction and it was supposed that alkoxy anion which was formed by the reaction of pentaerythritol with catalyst attacked carbonyl group of fatty oils. Furthermore, it was found that the composition of reaction products was almost independent of various reaction conditions and was consistent with the calculated values assuming the random distribution of fatty acid groups.
Choice of storage temperature, at room or low temperatures, for once heated oils and for fatcontaining processed foods at home has not drawn so much attention. Therefore, the conventional methods employed for fat analyses have been investigated if they can be used for detection of deterioration of heated soybean oil stored at low temperatures. Soybean oil heated for 30 min, 2 and 5 hr at 185°C was stored at 25, -5 and -25°C up to 150 days and each sample was analyzed for oxygen absorption (at 50°C), acid value, carbonyl value and fatty acid composion by gas liquid chromatography. The acid and carbonyl values of the samples stored in all the temperatures under consideration increased up to 3060 days, followed by decrease, indicating decomposition of acids and carbonyl compounds during the course of storage. Similarly, peroxide value of the samples stored at low temperatures increased up to 15 days, followed by decrease, whereas that of the samples stored at 25°C increased steadily. No significant differences in the proportions of fatty acids were observed between the samples before and after the storage when examined by gas liquid chromatography. However, the oxygen absorption curves obtained showed an absorption maxima or one or more plateaus when examined at a bath temperature of 50°C for 56 hr, and this may be attributed to the effects of some volatile compounds formed by heating and or autoxidation during storage. A white precipitate formed in the samples stored at -5°C was confirmed as triglycerides comprising relatively larger amounts of saturated fatty acids than those of soybeanoil. The decomposition of the oxygenated compounds as reflected by changes in acid, peroxide and carbonyl values in the samples stored at low temperatures suggests that these methods of analyses are not necessarily appropriate for detection of deterioration of oils stored at low temperatures, and therefore, further studies are necessary.