| Popis: |
The effect of dehydrating the rice bran before solvent extraction and its importance have been previously reported. In this paper this was reconfirmed by comparing the rice bran with corn germ which is a proper raw material for comparison. The maximum point of extraction velocity curve, remaining miscella in the extracted marc and drying and hygroscopic properties were discussed. In the case of corn germ : a) Area in the constant drying velocity curve and hygroscopic velocity are smaller than that of rice bran. b) Curve of solvent extraction velocity has a maximum at 3 percent moisture, and increase in the rate of extraction to raw material was small. It showed a large deviation in the figures obtained at the maximum drying and nearby conditions. c) Quantity of miscella remained in the extracted marc was less than one third of that of rice bran. Decrease in weight by drying was also less than the rice bran. From the above result, it was made clear that the rice bran has a characteristic difference from other materials, shown in the above (b) and (c) which come from the particle-size and the composition of rice bran in the solvent extraction process. Hot solvent extraction has more effect than the material-stirring extraction for rice bran. The differences in properties of extracted oil by different solvents were outstanding in color and color intensity, and other difference was little. The ratios of color intensity for trichlorethylene extracted oil : benzene ext. oil : pet. benzene ext. oil were 4 : 2 : 1. Freezing of pure benzene could be prevented by mixing 30 percent of pet. benzine, whereby the freezing point descend to -8°C, and this is confirmed by measuring specific gravity. |
