PROBLEM TO BE SOLVED: To provide a production method capable of easily producing a soybean fermented product which contains γ-amino acid and aglycon-type isoflavone at high contents and which has less bitter taste and is easy to eat.SOLUTION: A method for producing a soybean fermented product by aerobic solid culture using at least two of Rhizopus microsporus, R.oryzae and R.stolonifer, wherein the soybean fermented product cultured at a culture temperature of 20 to 30°C is further cultured at a culture temperature of 32 to 40°C, and the soybean fermented product contains γ-amino acid and aglycon-type isoflavone at high contents and has less bitter taste. The soybean fermented product contains at least 300 mg of γ-amino acid, at least 35 mg in total of daidzein and genistein, and total 500 mg at most of valine, isoleucine and leucine each based on 100 g of the soybean fermented product.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2019,JPO&INPIT【課題】γ-アミノ酪酸及びアグリコン型イソフラボンを高含有し、かつ苦味が少なく食べ易い大豆発酵物を、簡便に製造できる製造方法の提供。【解決手段】Rhizopus microsporus、R.oryzae及びR.stoloniferの内、少なくとも2種を用いた好気的固体培養による大豆発酵物の製造方法であって、20~30℃の培養温度で培養した大豆発酵物を、32~40℃の培養温度で更に培養する、γ-アミノ酪酸及びアグリコン型イソフラボンを高含有し、かつ苦味が少ない大豆発酵物の製造方法。大豆発酵物乾燥品100gあたり、γ-アミノ酪酸を少なくとも300mg、ダイゼイン及びゲニステインを合計で少なくとも35mg含み、かつバリン、イソロイシン及びロイシンの合計が多くとも500mgである、大豆発酵物の製造方法。【選択図】図1
