The decolourization of the rice bran oil dissolved in organic solvents by mean of the ion exchange resins was investigated. The results were as follows : (1) This method was not effective for the decolourization of the crude rice bran oil, but it was very effective for the rice bran oil which had already been treated with H3PO4 and H2SO4 etc. (2) In decolourization of the rice bran oil after treating with acids, the anion exchange resin (Amberlite IRA-401 OH form) was more effective than the cation exchange resin (Amberlite IR-120 H form). (3) Using both the anion and cation exchange resins at a run was much effective for the decolourization of the rice bran oil, whereby the anion exchange resin is to be used prior to the cation exchange resin.
Authors got the next two results as a part of researches about the refining of rice bran oil having the speciality of high acidic and much content of moisture and impurities. For the separation of moisture and impurities, the centrifuge process was superior than heating and settling process. For optimum conditions of the centrifuge process, temperature was 80 to 90°C, rotation 1, 400 rpm with 71 cm diameter at 1 ton per hour capacity, whereby moisture and impurities were improved to be lowered from 5% to 1%. The darkening of bleached high acidic rice bran oil was found not to be attributable only by the color of metallic soap but by the pigment activated by metallic ions. For the material of storage vessel of the bleached high acidic oil, the tin aluminium or zinc were suitable and tin plated iron can was practically safety for 5 months, while iron drum has darkened the oil by 5 times.
In the high pressure hydrogenation of high acid valued rice bran oil, authors appointed the optimum composition of unreduced Cu-Ni catalyst in industrial use. But the catalyst could not be useful in low pressure hydrogenation unless roasting. When there is 1.0% residue of extracting solvent trichloroethylene in oil, its catalytic poisonous action is less than that of formerly believed, but it has a good influence for bleaching and for the hydrogenating velocity regulation, in the high pressure hydrogenation. In the high pressure hydrogenation, up to 2.0% water content is not bad for results, but it is gradualy influenced from 2.0 to 8.0%, and the hydrolysis of fat is seen according with water content. The soapstock could not be hydrogenated by 1.0% nickel oxide catalyst. While, if recovered and then refined, it can be hydrogenated by unreduced Cu-Ni even 1.0% catalyst.
For the analysis of nonionics in cationics-ampholytics-nonionics ternary mixtures, the quantitative separation of nonionics from the mixtures by ion-exchange technique and the determination of isolated nonionics by Schönfeldt method and UV absorption spectrophotometry have been investigated, and the “Cation Exchange-Schönfeldt” method and “Semimicro Cation Exchange-UV Spectrophotometry” method have been developed. The methods consist of two steps : (1st) ion-exchange separation of nonionics from mixtures by means of a column method and (2nd) determination of isolated nonionics by Schönfeldt method or UV absorption spectrophotometry. The results showed that nonionics was separated quantitatively from the mixtures in 10% isopropanol aqueous solution, by using Amberlite IR 120 (H+) and adjusting to pH 2.02.5, and that the isolated nonionics was determined with satisfactory accuracy by Schönfeldt method and by measuring extinction of the effluent at 277mμ (λmax of nonionics : POE Nonylphenol).
For the rapid and accurate analysis of nonionics in Cationics-ampholytics-nonionics ternary mixture, the direct determination of nonionics in the mixture without separating the component surfactants has been investigated and the “Direct UV Spectrophotometry” method was developed. The cationic and nonionic components exhibited the characteristic absorption bands but the ampholytic (imidazoline type) didn't. The λmax was determined as follows : Lauryl benzyl dimethyl ammonium chloride; 257.5, 263, 269.2 mμ, POE nonyl phenol (n=89); 277, 283.5 mμ. Vierordt' method could not be applied to the analysis of mixture, while our experimental results showed that at 277 mμthe observed extinctions of cationics and ampholytics were 0 at the concentration less than 0.03 and 0.025%, respectively, and that the nonionics in mixture could be determined by measuring the extinction of the sample solution, of which the concentration of each component being nonionics ; 0.0020.036%, cationics;<0.03%, and ampholytics;<0.025%.
In the studies of performance tests of surface active agents, new Semimicro Disc Methods of Wetting Test (Horizontal Method and Vertical Method) have been developed in our laboratory. The data obtained by the new “Horizontal Method” agree thoroughly with those by the original macro-method. The apparatus and operation have been improved and simplified. The new “Vertical Method” is applicable in transparent or opaque solutions. The accuracy of measurement was improved by the “Vertical Method”, although the manipulation of the “Horizontal Method” is a little simpler. The influence of the load and the depth of the disc in the test solution on the sinking time was investigated, and it was concluded that the sinking time is a inversive linear function of load, i.e. the load increases, accordingly the sinking time decreases. The sinking time is not affected by the depth of the disc between 10 and 15 mm. The accuracy of measurement increases in proportion as the load decreases.
In the studies of performance tests of surface active agents, a new semimicro continuous method of wetting test, the “Tensiometer Method” has been developed in our laboratory. The method consists of measuring the change of apparent density of a standard canvas or felt disc, immersed in a test solution, with Du Nouy tensiometer. The change of apparent density is plotted against time on semi-log paper, and the entire progress of wetting is clearly shown by the apparent density-time curves. The method is simple, accurate, needs only very small quantities of test solutions, can be applide to dye-, mercerisation- and other transparent and opaque processing solutions, and also serves as rewetting test.
Preparing 5 (almost 1/2 lb) samples, for each of 8 kinds of bakery margarine from the market, observation was made on appearance, moisture, P.O.V., A.V, and color of the surface and the inside every month for 5 months. Moisture measurement shows what is hard and fragile in structure has a high rate of moisture reduction, and what is soft has a low rate. But inside observation shows any minor change during the whole period, showing a little change with hard one. All the samples show an increase in P.O.V. which is in proportion to linoleic acid content in general, because they contain no milk ingredient. There is a little difference between the surface and the inside, same as well in the first report. Oxidation is found to take place at the inside almost at the same level as is on the surface. Most samples show very small increase in A.V. since they have no hydrolysing element such as mold and coconut oil. And the difference between the surface and the inside is considerably small. All the samples discolor on the surface. The surface color become heavier only in the first month, but then after, sharp discoloration occurres, and the difference in color value between the surface and the inside grows increasingly wider. Compared with household margarine which almost did not discolor, the average value of the difference for bakery margarine is 7.0 against 0.9 for household margarine, when expressed the difference value between the surface and the inside in the 5th month figures.