Correlation between crystal habit and the modification of crystals by growth conditions was examined by electron microscope, polarization microscope, and X-ray diffraction, using a single crystal obtained from 1-monostearin by a solution method. 1) The crystal growth from ethyl alcohol solution gave a single crystal of leaf-like pattern, the growth form was not uniform, and the steps on the crystal surface were irregular (Fig.-1). Crystal growth from benzene and carbon tetrachloride solutions gave a lamellar single crystal, forming polyhedral or rhombic crystals by the growth in a definite direction, and the crystal surface showed a two-dimensional growth in the direction of a and b axes and a pattern formed through a screw dislocation (Fig.-2, 3). Consequently, mechanism of the crystal growth of 1-monostearin can be explained by both the theories of growth by the formation of a two-dimensional nucleus and that by screw dislocation. 2) The long spacings of the single crystals grown from ethyl alcohol, benzene, and carbon tetrachloride solutions agree with the β-type long spacing of 1-monostearine. Therefore, the morphology of a single crystal is affected by the kind of solvent used, its concentration, and temperature of crystal growth, but these conditions have no effect on crystal modification.
The simple lipids of five species of Polyporaceae (Phellinus yucatensis, Polystictus polyzonus, Trametes dickinsii, Grifora gigantea and Granoder leucophaeus) were investigated. The fatty acid compositions of the simple lipids were determined by GLC. The main fatty acids common to these species were found to be C16-saturated and C18-unsaturated acids. The sterol fraction was isolated from the unsaponifiable matter by column chromatography and its composition was determined by GLC. The main sterols were proposed to be ergosterol (G. gigantea) and 7, 22-ergostadienol (P. yucatensis, P. polyzonus, T. dickinsii, G. leucophaeus) from their mp, IR, GLC, and MS.
Unsaturated nitriles were synthesized in good yields from 6-methyl-5-hepten-2-one and active methylene compounds containing nitrile group. From methylheptenone and malononitrile, 2-cyano-3, 7-dimethyl-2, 7-octadienenitrile was obtained in 91% yield. The unsaturated nitriles were alkylated at the 3-position by various Grignard reagents. Furthermore, reduction and hydrolysis of these unsaturated nitriles were examined.
Soybean oil was oxidized using 7, 000 lux fluorescent light for different time periods. The volatile compounds were isolated by bubbling purified nitrogen through the oil heated at 150°C and collected on activated charcoal. These compounds were extracted from charcoal with carbon disulfide and then analyzed by temperature programmed gas chromatography. The used oils were evaluated by expert panels. Good correlations were found between total gas chromatographic peak areas and the adjusted grassy flavor scores of the soybean oil. The threshold level of the grassy flavor in the soybean oil corresponds to about 400 expressed as total peak intensity ratio of the volatile compounds. The technique provides good reproducibility and is used for evaluating the commercial soybean oil during storage.