The characteristics of extracts and precipitates after extraction at different water temperature (25, 50, 75, 95oC), ethanol ratio (25, 50, 75, 100%), and extraction method (stir, soak, autoclave) of yam powder and raw yam were investigated. The total polyphenol content was the highest in the 50% ethanol extract of yam powder. The DPPH radical scavenging activity was the highest in the 75% ethanol extraction and the crude saponin content was the highest in the 95oC water extraction. Tyrosinase inhibitory activity was the highest in 95oC water extraction, low concentration of ethanol extraction, and autoclave extraction. The peak viscosity, trough, and final viscosity of the precipitates increased after ethanol extraction, whereas decreased after the 95oC water extraction and the autoclave, indicating the destruction of starch granules. This was confirmed by observing the starch granules broken using the SEM. The significance of this study was to investigate the possibility of the use of yam resources as a material, processing product development, skin beauty functional food and cosmetic material.

Recently, the Ranque-Hilsch vortex tube is widely used for the local cooler of industrial equipment for special purpose. Although many studies on energy extraction in the vortex tube using air as the working fluid have been made so far, a few experimental studies treated solid particles extraction for incompressible fluid. So, an experimental study for the solid particles extraction in the vortex tube(Ranque-Hilsch vortex tube) using the water which is essentially an incompressible fluid is presented. The experiments were carried out with various cold end orifice diameter ratios ranging from 0.25 to 0.70, the input pressure ranging from 1 to 3MPa was considered. The emphasis was given to examine the effect of geometry factors of vortex tube at working fluid(water) for solid particles(Al2O3) extraction. The optimum geometry factor and inlet pressure for the maximum solid particles extraction was found that the smaller cold end orifice diameter ratio and the higher inlet pressure in experimental condition increase.