[in Japanese]

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Non volatile by products during deep fat frying of trilaurin and hydrogenated coconut oil were studied. After volatile products were removed from the fat used for frying, the fat was converted into methylester.
From methylester, non-polymerized polar ester and polymerized product were separated by LC and TLC followed by distillation. Then, they were gaschromatographed.
The non-polymerized polar ester was mainly keto-ester. Carbon numbers of keto-ester were distributed as to those of original fats.
The molecular weight of polymerized product from trilaurin was 460 and had two ester groups in a molecule.
The composition of the polymerized product was investigated by depolymerization and MS, though the parent peak was not present.

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Deodorized kapokseed oil foams vigorously when used for deep fat frying around 180°C. This foaming tendency is due to the presence of cyclopropenoid in the oil. It is also known that the concentration of cyclopropenoid in the cottonseed oil is reduced by treatment with carboxylic acid.
In this paper, kapokseed oil was treated with carboxylic acid to improve foaming tendency.
It was found that this foaming tendency could be reduced by treatment with carboxylic acid provided that the cyclopropene ring is not cleaved by bleaching and deodorization prior to treatment with carboxylic acids. Acetic acid and safflower fatty acid were used as carboxylic acids.
Infrared spectra of the acetic acid-treated kapokseed oil showed absorption at 1020 cm^-1 which may be associated with the formation of the cyclopropane ring.

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Protein denaturalization in the aqueous solution of surfactant was discussed by measuring the degree of the inhibition of invertase activity. Evaluation of the human skin-roughness was performed by the dropping method and the immersion method. A strong correlation was observed between the inhibition o invertase activity by surfactants and the skin-roughness.
This screening method is an excellently valuable selecting mild surfactans for skin.

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The influence of metal ions (Cu (II), Fe (III), Fe (III)) and the effect of erythro- and threo-2-methyltartaric, and meso- and threo-2, 3-dimethyltartaric acids as chelating agent on the oxygen absorption in O/W-type emulsion were investigated by employing a polarographic Beckman Oxygen Analyzer, Model 777. Soybean oil with different P.O.V. and water were emulsified into O/W-type emulsions using Tween-40, and the decrease of dissolved oxygen was measured in the presence of Fe (II), Fe (III) and Cu (II) ions. In order to evaluate the effect of these acids, an acid solution (10^-1 mol/l, 1 ml) was added to the emulsion. Then, the metallic solution (0.5 × 10^-1 mol/l, 1 ml) was added to the same emulsion, and the variation in the dissolved oxygen was measured. The results of these measurements revealed that the oxygen absorption increased in the order of Fe (II) >> Fe (III) > Cu (II) and the deteriorating effect of these metal ions was suppressed by the addition of these acids.
When the stabilizing effect of these acids was compared each other, the effect increased in the order of non-substituted > monomethyl-substituted > dimenthyl-substituted, that is, tartaric > 2-methyltartaric > 2, 3-dimethyltartaric acids. Moreover, comparing the effect of the isomers of these acids to each other, erythro-form acids are clearly seen to function as a more effective antioxidant. In the test for antioxidant activity by means of A.O.M. and Shaal Oven Test, the similar results were obtained.
On the basis of these data, it can concluded that ; (1) as for the isomers of these acids, the difference of the stabilizing effect on the oil as chelating agent can be attributed to the equilibrium constants of these acid-metal complexes ; (2) in addition, as for the monomethyl-, dimethyl- and non-substituted acids, it seemed reasonable to assume that these effects as antioxidant may be attributed to the methylene or methin group on the α-position of acids.

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The X-ray diffraction patterns of vegetable fats, such as hydrogenated coconut oil, hydrogenated rape seed oil, palm oil and cacao butter, were determined with a sample cell at various temperatures, which was regulated by thermomodule near a room temperature. (Fig.-1.1)
It has been found that hydrogenated coconut oil, hydrogenated rape seed oil and palm oil exhibit β' form after heat treatment such as in S. F.I. determination.
The authors attempted to determine the solid content from the X-ray diffraction pattern, by dividing it into two parts; the one was scattered by crystal phase (solid phase) and the another by liquid phase. (Fig.-6) Thereafter, it was found that the solid content can be estimated by ratio of two peak intensities, (I_{2θ=23, 1}/I_2θ=18.1). These methods could be used for the measurement of solid content. (Fig.-8·1, 8·2)
Although polymorphism of cacao butter was very complicated, the X-ray diffraction pattern at various stages can be easily obtained by the use of the sample cell. (Fig.-9, 10)

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