Study Of Isoflavone Production From Soy Molasses

Isoflavones are a flavanoid subgroup found in several plants. In soybeans, they are in12main forms:Daidzein, Genistein, Glycitein, and their respective acetyl, malonyl and aglucon forms. There is an increasing interest in these compounds due to their biological effects, including estrogenic and fungitoxic activities. Isoflavones have been associated with a decreased risk of breast, prostate cancers and are being studied for the prevention of menopausal symptoms, coronary heart disease and osteoporosis. Because of these, soybean isoflavone can be used in fields of functional food and medicine.Soy molasses is a byproduct obtained from processing of soybean protein concentrate, which contains soy isoflavone and is always used as livestock feed. This study was to investigate the extraction of isoflavone from soy molasses and the separation isoflavone using macroporous resin.The optimized condition of extracting isoflavone from soy molasses had been gained. First, soy molasses-water (1:4, v:v) mixtures were adjusted pH to7. Secondly, the system was added3g Ca(OH)2and flocculated for30min. After centrifugation10min at4000rpm, the deposition was washed with water for two times. Finally, the pH value of the solution was changed to7again and the raw material solution was gained after centrifugating for10min at4000rpm. Concentration of the isoflavone was400mg·L-1and yield was higher than70%.Effects of ultrasonic to the yield were also investigated in this work. Soy molasses were diluted with water (1:4, v/v). Results showed that large amounts of isoflavones are extracted at20℃and the recoveries of product are obtained after ultrasonic processing for10min instead of mix-stirring. The isoflavone yield was gained about80%.Then the solution gained from soy molasses was refined using ADS-7resin and the condition of desorption was also investigated. Concentration of isoflaovne was300mg·L-1and4BV of water was used to wash the column to remove sugar, salt and water-solubility coloring matter. Results showed that the highest purity was obtained when the soy isoflavone was eluted by70%(v:v) ethanol. The purity and whole recovery of isoflavone were63.51%and63%, respectively.Finally, the low concentration soy molasses solution was refined using ADS-7resin directly without preparation. The purity of product gained was about40%. When two columns were connected, the recovery of the whole system had been improved and gained about85%. After three times of circulation, the purity and recovery of isoflavone did not change distinctly. After regeneration, the resin was used again to refine isoflavone. Results showed that purity and recovery of isoflavone were about30%and82.56%, respectively. That means the resin used is promising to refine isoflavone for industrialization.