The object of this study is to elusidate the relation between fat stability and the type of fat deterioration occured during deep fat frying. Soybean oil was deteriorated in the continuous water-spraying and heating system' by controlling the supply of air and water, and deteriorated oils of four types were prepared. Type-1 was obtained by heating without air and water (Experiment-1), Type-2 was with air but without water (Experiment -2), Type-3 was with water but without air (Experiment-3), and Type-4 was with air and water (Experiment-4). Experimental condition and properties of deteriorated oils were shown in Table-15. The fat stability of four types of deteriorated oils above mentioned were compared by the length of induction period, and the effect of antioxidants or synergists to these oils were evaluated (Fig.-12). Induction period and effectiveness of antioxidants were measured by weighing method mentioned by Dr. H.S. Olcott et al. It was observed that, in Type-1, no any deterioration occured, therefore, good stability was maintained, and the addition of antioxidants or synergist was very effective. In Type-2 and 4, thermal oxidation occured, and the fat stability lowered very rapidly and its stability could not be recovered almostly by the addition of synergist, and also, the addition of antioxidants was, no longer, uneffective for the oil when the oil went over a certain deterioration limit. In Type-3, thermal oxidation did not occur, but the hydrolysis occured and the fat stability also lowered, but its stability could be effectively recovered by the addition of antioxidants or synergist. This result shows that the lowering of fat stability in Type-3 was not from the deterioration of oil itsself, but from the loss of antioxidants by steaming and from the increase in iron content came from the fabricating material. The lowering of fat stability of soybean oils thereinto added the antioxidants or synergist before heating, and the influence of fabricating material of testing beaker to the fat stability were also examined.
The side reaction during catalytic hydrogenation of oil was investigated. Soybean oils with peroxide number 5 and 101 were hydrogenated and deoderized. The deoderized oil was fractionated into polar glyceride and non-polar glyceride by column and thin-layer chromatography. The polar glyceride was converted to methylester and again fractionated into polar acid ester and non-polar acid ester. The IR spectra and Rf on TLC of the polar acid ester were identical with those of ω-hydroxy acid ester which was derived from oleyl alcohol. In the non-polar acid, the lower fatty acid which had not been contained in original soybean oil was found by gas chromatography. These lower fatty acid and polar acid were found only in the hydrogenated oil from the oil of peroxide number 101 and not found from the oil of peroxide number 5. The mechanisms of formation of those acids were discussed.
Lauric acid was chlorophosphonated under the following conditions : 0.15 mol of lauric acid was dissolved in 0.3 mol of phosphorus trichloride, followed by introduction of dried oxygen into the solution with the flow rate of 70 ml/min for 3 hr. The product was distilled under vucuum after treating with methanol. The distillation residue was then fractionated by silica gel column chromatography, obtaining phosphorus-containing product. This product was confirmed as monophosphonolauric acid by means of elementary analysis and potentiometric titration. From the result of NMR and IR spectroscopic analysis of the product in comparison with the spectra of the synthesized α-phosphonolauric acid, it was confirmed that the chlorophosphonation occured on carbons other than α- and terminal carbons in the alkyl chain. In the case of the chlorophosphonation of methyl laurate, the yield of phosphonolauric acid was slightly higher than in the case of lauric acid. The properties of the product from methyl laurate were the same with those from lauric acid.
Authors synthesized poly-p-vinyl benzoic acid-ion exchange resin which was converted to the peracid type resin by using hydrogen peroxide and methanesulfonic or p-toluenesulfonic acid. The peracid type resin of oxidation capacity 2.13 m eq / g was obtained and the conversion of COOH to COOOH was 48.4% in the best condition. The conversion of COOH to COOOH increased from 15 to 30% with increase in the cross-linking degree from 1 to 41%. The conversion rate was relatively slow as comparing with that observed in the case of peracid type XE-89, but the loss in the conversion was little. The stability in the air was better than that in the case of peracid type XE-89, but worse at 40°C in benzene, methanol and dioxane. Cyclohexene and methyl oleate were epoxidized by the peracid type resin in the yields of 5060%.
When nonionics, especially polyoxypropylene-polyoxyethylene blockpolyether type of high molecular weight, are used as emulsifiers, the most important factor affecting substantial emulsion stability seems to be mechanical strength (rheological property) of the interfacial film. Hence, authors studied the relation betwen interfacial viscosity and stability of practical emulsion, energy of activation for emulsion coalescence, and coalescent rate of a single oil drop or an aqueous drop to the same phase. It was found in the case of a nonionic PL-104 emulsifier that about 4 hr are necessary to accomplish nearly complete adsorbed film at benzene-water interface. It was also found that there exist good correlation between emulsion stability and activation energy, and between interfacial viscosity and coalescent rate of drops in the case of benzene-water system. However, no correlation existed between activation energy (or emulsion stability) and interfacial viscosity (or coalescent rate of drops). This seems to be due to difference of interfacial conditions between them.