| Summary: | 碩士 === 國立中興大學 === 化學工程學系 === 91 === This study preliminarily inspected the batch hot pressurized water extractions of five isoflavones and saponins from defatted soybean flakes (DSF) using the simulation optimization approach known as “steepest ascent”. A suitable condition of batch hot pressurized water extraction was applied to carry out the semi-continuous process testing. Then, the effects of process pressure (60~735 psig), process temperature (60~120 C), flow rate (10~25 ml/min) of solvent, and the solid to solvent ratio were investigated in terms of solubility, total yield, and the recovery of five isoflavones. Finally, Taguchi experimental design was used to examine the influence of each independent variable on the recovery of total isoflavones (TIF) and total soyasaponins (TSP) extracted using semi-continuous process. The steepest ascent design of batch hot pressurized water process revealed that extraction at 110 C, 641 psig and 2.3 hours did recovery 99.72 % TIF from 180g DSF. Furthermore, the temperature effect is predominant for batch as well as semi-continuous hot pressurized fluid extractions, and no pressure effect between 100 and 640 psig. It also revealed increasing the flow rate of fluids or decreasing the loading of DSF, and high content of ethanol should enhance the recovery. Taguchi method definitely disclosed that the content of ethanol (95 % EtOH) and flow rate (25 ml/min) of solvent are two major operating parameters affecting the recovery of TIF and TSP for the semi-continuous process. Purifying the extracts from batch hot pressurized water obtained a solid with 9.40 % yield, 36.98 % purity, 48.95 % TIF recovery and a solid with 9.37 % yield, 38.40 % purity, 66.16 % TIF recovery, by individually using Amberlite XAD16-HP and DIAION HP21 resins. Finally, Amberlite XAD16-HP resin purified the extract from hot pressurized ethanol could obtain a solid with 7.34 % yield, 58.00 % purity, and TIF 40.90 % recovery. The overall recoveries of TIF from all purifications are closed to 99 %.
|
|---|
