醇沉法纯化大豆异黄酮

Purification of soybean isoflavone by ethanol precipitation

大豆粕经70%乙醇提取后,提取液回收乙醇后得到浓缩液。以浓缩液为原料,采用醇沉法纯化大豆异黄酮,通过单因素和正交实验确定最佳工艺参数为:浓缩液质量分数为30%,加5倍量95%乙醇搅拌10 min进行醇沉,上清液回收乙醇后调其质量分数为5%,30℃下静置4 h,再以2 000 r/min离心10 min,对沉淀进行水洗,弃去水洗液,沉淀物于60℃干燥。在此条件下,所得产品大豆异黄酮含量达60%以上,得率为0.072 2%。

The soybean meal was extracted with 70% ethanol, the extract was evaporated to recover the solvent and obtain the concentrated solution. The purification of soybean isoflavone from the concentrated solution by ethanol precipitation was studied. Through single factor and orthogonal experiment, the optimal purification conditions were attained. The mass fraction of the concentrated solution was first adjusted to 30% , and then added 95% ethanol （ ratio of ethanol to material 5：1 ） and agitated for 10 min to obtain the supernant; after the recovery of ethanol, the mass fraction of the supernant was adjusted to 5% and standed for 4 h at 30 ℃ then was treated to obtain the sediment by centrifugating 30 min at 2 000 r/min ; the sediment was washed by water and dried at 60 ℃ to obtain the finished product. The soybean isoflavone content of the finished product was 60%, and the yield was 0.072 2%.