Enrichment of two isoflavone aglycones in black soymilk by Rhizopus oligosporus NTU 5 in a plastic composite support bioreactor

Chi Te Liu, Mei Hui Erh, Shin Pin Lin, Kai Yin Lo, Kuan I. Chen, Kuan Chen Cheng

Research output: Contribution to journalArticle

5 Citations (Scopus)

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%).

CONCLUSION: A repeated-batch PCS fermentation system was established to accelerate the deglycosylation rate of isoflavone in black soymilk.

Original languageEnglish
Pages (from-to)3779-3786
Number of pages8
JournalJournal of the Science of Food and Agriculture
Volume96
Issue number11
DOIs
Publication statusPublished - Aug 1 2016
Externally publishedYes

Keywords

  • black soymilk
  • isoflavone
  • plastic composite support bioreactor
  • Rhizopus oligosporus
  • β-glucosidase

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Agronomy and Crop Science
  • Nutrition and Dietetics

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