Abstract:

MRS medium fortified with soybean isoflavones was fermented by Lactobacillus delbrueckii subsp. Bulgaricus at 37 ℃. As a result, soybean isoflavones were degraded, producing equol. Polyamide resin was used for purifying the crude equol extract from the harvested fermentation broth after 48 h fermentation. The optimal adsorption/desorption conditions were determined by single factor and orthogonal array design methods to be: sample concentration 2.40 μg/mL at pH 5, adsorption duration 6 h and amount of 80% ethanol used for equol desorption at a flow rate of 0.5 mL/min 45 mL. Under such conditions, the adsorption ratio of equol was 45.36%, and the desorption raio 60.00%.

Key words: equol, polyamide, purification