Abstract: To study the inhibitory ability of acid-hydrolysate of isoflavones in Fermented Soybean.The ability of acetylcholinesterase inhibitory was determined with Ellman colorimetry method.An UPLC method was established for the simultaneous determination of daidzin,glycitin,genistin,daidzein,glycitein and genistein in fermented soybean.The optimal conditions for the hydrolysis of isoflavones were found to be at 70 ℃ with 3 mol/L HCl methanol for 5 h,and the acetyl cholinesterase inhibition rate reached 82.37%.The acetyl cholinesterase inhibition rate had significant positive correlation with isoflavone aglycone (P<0.01).

Key words: fermented soybean, isoflavones, acetyl cholinesterase, inhibition rate