Effects of cellulase on extracting isoflavone from soybean residue

Soybean residue from soybean oil manufacturers can be used to extract isoflavone.Soybean residue was pre-hydrolyzed by cellulase from different microbes,then the hydrolyzate was obtained and the solid residue was extracted by using 70% ethanol.When using the cellulase from Bacillus sp ZU-4,the isoflavone yield was 1.4 times as that by normal ethanol extraction and the isoflavone composition was unchanged.When using the cellulase from Aspergillus niger ZU-7,the isoflavone yield was not increased but glucoside isoflavones were transformed to aglycones.By pre-hydrolysis with cellulase from Trichoderma reesei ZU-5,the isoflavone yield was increased by 1.6 times and at the same time the isoflavone composition was transformed to aglycones with higher physiological activity.The optimal dosage of cellulase from Trichoderma reesei ZU-5 was 15 FPIU(Filter Paper International Units)·(g soybean residue)~(-1) and the treating time was 36 h.When selecting macroporous resin for isoflavones absorption and desorption,the macroporous resin with weak polarity was proper for purifying aglycone isoflavones.