Changes in antioxidant capacity, isoflavone profile, phenolic and vitamin contents in soymilk during extended fermentation

Danyue Zhao, Nagendra P. Shah

Research output: Journal article publicationJournal articleAcademic researchpeer-review

48 Citations (Scopus)

Abstract

In this study, the influence of lactic acid bacteria fermentation on the antioxidant capacity, phenolic compounds and vitamins profile of soymilk with different final fermentation pH values (pH 4.55, 4.15 and 3.85) was examined. Fermented soymilk (FSM) with a final pH of 3.85 exhibited relatively higher antioxidant capacity than samples terminated at pH 4.55 or 4.15, as shown from results of Folin-Ciocalteu assay (57.3-63.8 mg GAE/100 mL FSM), DPPH-radical scavenging efficiency (30.0-36.5%) and ferricyanide reducing power (1.13-1.58 mg AAE/100 mL FSM). Among all products, Lactobacillus rhamnosus WQ2-fermented soymilk showed the highest antioxidant level among the four Lactobacillus species, while Lactobacillus acidophilus CSCC 2400 possessed the best ability to deglycosylate isoflavone glucoside (IG), reducing IG concentration by 60.8%. Four vitamins, three phenolic acids, one flavanol, and six isoflavones were detected in fermented and non-fermented soymilk by HPLC-DAD. The contents of antioxidant compounds in FSM were closely related to reducing power and anti-radical ability. In addition, antioxidant capacity was highly correlated with proteolytic activity. This study also demonstrated the potential of extended fermentation to enhance the overall health-promoting property of the products.

Original languageEnglish
Pages (from-to)454-462
Number of pages9
JournalLWT - Food Science and Technology
Volume58
Issue number2
DOIs
Publication statusPublished - Oct 2014
Externally publishedYes

Keywords

  • Hong Kong
  • Isoflavones
  • Phenolic compounds
  • Soymilk fermentation
  • Vitamins

ASJC Scopus subject areas

  • Food Science

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