Abstract:

【Objective】 The new treatment method —heat decomposed technology has been put forward to improve the situation of diosgenin from Dioscorea zingiberensis C.H. Wright. The wastewater of traditional hydrolysis process is called as the king which is great acidity, thick colour, high organic matter concentration. There isn’t an appropriate process to treat the wastewater successfully in practical engineering. 【Method】 The tubers were crushed at higher temperature and pressure in saturation steam medium. The diosgenin peeled from starch and cellulose, and can be extracted directly. 【Result】 The process optimization and the mathematic mold by response method are gotten. The effect of heat decomposed is better with higher pressure, longer holding time, and moderate material amount. The best conditions as follows: the steam pressure 1.4 MPa, holding 30 min, the material 3.5 kg and the product rate 1.745%. The treated material was better with weak color when CO2 added, but the acidity was increased slightly, and the holding time needed longer. 【Conclusion】 There is no acid, alkali reagent in the whole process. What’s the most important is no washing and no wastewater. So it is the real pollution-free technology.

Key words: heat-decomposed, Dioscorea zingiberensis C.H. Wright, diosgenin, response method