title: Enrichment of two isoflavone aglycones in black soymilk by Rhizopus oligosporus NTU 5 in a plastic composite support bioreactor.
abstract: BACKGROUND
  A plastic composite support (PCS) bioreactor was implemented to evaluate the effects on isoflavone deglycosylation in black soymilk fermented by Rhizopus oligosporus NTU 5.
  
  
  RESULTS
  Evaluation for the optimal PCS for mycelia immobilisation was conducted, which led to the significant results that the most mycelium weight (0.237 g per PCS, P < 0.05) is held by an S-type PCS; therefore, it was selected for black soymilk fermentation. It was found that the PCS fermentation system without pH control exhibits better efficiency of isoflavone bioconversion (daidzin to daidzein, and genistin to genistein) than the one with pH control at pH 6.5. As for the long-run fermentation, those without pH control indeed accelerate the isoflavone bioconversion by continuously releasing β-glucosidase into soymilk. Deglycosylation can be completed in 8 to 24 h and sustained for at least 34 days as 26 batches. The non-pH-control fermentation system also exhibits the highest total phenolic content (ranged from 0.147 to 0.340 mg GAE mL(-1) sample) when compared to the pH-controlled and suspended ones. Meanwhile, the black soymilk from the 22nd batch with 8 h fermentation demonstrated the highest DPPH radical scavenging effect (54.7%).
  
  
  CONCLUSIONS
  A repeated-batch PCS fermentation system was established to accelerate the deglycosylation rate of isoflavone in black soymilk. © 2015 Society of Chemical Industry.
authors.affiliation: Institute of Biotechnology, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, Taiwan.
authors.forename: Chi-Te
authors.initials: CT
authors.lastname: Liu
authors.affiliation: Graduate Institute of Food Science & Technology, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, Taiwan.
authors.forename: Mei-Hui
authors.initials: MH
authors.lastname: Erh
authors.affiliation: Institute of Biotechnology, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, Taiwan.
authors.forename: Shin-Pin
authors.initials: SP
authors.lastname: Lin
authors.affiliation: Department of Agricultural Chemistry, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, Taiwan.
authors.forename: Kai-Yin
authors.initials: KY
authors.lastname: Lo
authors.affiliation: Graduate Institute of Food Science & Technology, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, Taiwan.
authors.forename: Kuan-I
authors.initials: KI
authors.lastname: Chen
authors.affiliation: Institute of Biotechnology, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, Taiwan.|Graduate Institute of Food Science & Technology, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, Taiwan.
authors.forename: Kuan-Chen
authors.initials: KC
authors.lastname: Cheng
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000378:metabolism; D005285:Fermentation; D005511:Food Handling / Q000379:methods*; D019833:Genistein / Q000378:metabolism; D006027:Glycosides / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007529:Isoflavones / Q000378:metabolism*; D010851:Picrates / Q000378:metabolism; D012233:Rhizopus / Q000378:metabolism*; D041942:Soy Milk / Q000378:metabolism*; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D006027:Glycosides; D007529:Isoflavones; D010851:Picrates; C040641:genistin; C013908:daidzin; C004742:daidzein; C004931:1,1-diphenyl-2-picrylhydrazyl; D019833:Genistein; D001617:beta-Glucosidase
keywords: Rhizopus oligosporus; black soymilk; isoflavone; plastic composite support bioreactor; β-glucosidase