The effect of Aspergillus oryzae and Rhizopus aspergillus fermentation on daidzein content in edamame (glycine max)

Abstract

Background: Previous studies show that fermentation using Aspergillus oryzae and Rhizopus oligopsorus increases the aglyconic isoflavone in soybean with the highest content reached on the seventh day. Still, no research has been done on edamame. Objective: This study was conducted to validate the method and determine aglyconic isoflavone, daidzein, content in non-fermented and A. oryzae and R. oligopsorus fermented edamame using TLC densitometry.     Method: TLC densitometry method used was validated, then used to determine daidzein content in non-fermented edamame, and edamame fermented with the combination of A. oryzae and R. oligopsorus for four days (D1 - D4). Results: The TLC method met all the validation method, except for the selectivity. The daidzein content on non-fermented and fermented edamame (D1 - D4) was 0.0354+1.49*10-3, 0.0099+1.19*10-3, 0.0118+0.16*10-3,0.0156+0.65*10-3, and 0.0618+10.67*10-3, respectively. Conclusion: The highest daidzein content was reached at the fourth day of fermentation.