African Journal of
Agricultural Research

  • Abbreviation: Afr. J. Agric. Res.
  • Language: English
  • ISSN: 1991-637X
  • DOI: 10.5897/AJAR
  • Start Year: 2006
  • Published Articles: 6863

Full Length Research Paper

8-Hydroxygenistein formation of soybean fermented with Aspergillus oryzae BCC 3088

Chirtchai Punjaisee1, Chaiyavat Chaiyasut1*, Sunee Chansakaow1, Somsak Tharata2, Wonnop Visessanguan3 and Suchart Punjaisee4
  1Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand. 2Central Laboratory (Thailand) Co. Ltd., Thailand. 3National Center for Genetic Engineering and Biotechnology (BIOTEC), Thailand Science Park, Pathumthani, Thailand. 4Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.
Email: [email protected]

  •  Accepted: 18 January 2011
  •  Published: 18 February 2011



The isoflavone content of soybean was studied by incubated Thai native soybean (Glycine max (L) Merr, SJ.2) with Aspergillus oryzae BCC 3088.   The changes of the isoflavone analogue content were analysed by HPLC. Mass spectrometry was used to confirm the presence of substances in fermented soybean with the authentic standards. After fermentation, total glycosides content of soybean fermented with A. oryzae BCC 3088 decreased but the proportion of aglycone markedly increased. As for the increases of isoflavone aglycone during the fermentation, the proportion of aglycones in total isoflavones was markedly higher in soybeans fermented with A. oryzae BCC 3088 than was those from uninoculated soybean. Furthermore, 8-hydroxygenistein (8-OHG) was found at the fourth day of fermentation. Therefore, fermentation of soybean with A. oryzae BCC 3088 results in higher levels of isoflavone aglycones and their corresponding, 8-OHG, which may enhance more health benefits than unprocessed soybean.


Key words: Aspergillus oryzae, fermented soybean, isoflavone, 8-hydroxygenistein.