Antiradical and tea polyphenol-stabilizing ability of functional fermented soymilk-tea beverage

Danyue Zhao, Nagendra P. Shah

Research output: Journal article publicationJournal articleAcademic researchpeer-review

36 Citations (Scopus)

Abstract

This study examined the potential of two-step fermentation to preserve TPs in functional soy-tea beverage. Fermented soymilk-tea (FST) was produced by culturing Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus and Bifidobacterium longum in soymilk supplemented with tea extract (TE). Total phenolic content (TPC) and anti-radical activities were determined for FSTs and fermented soymilk (FS). A HPLC method was employed to quantify nine major tea phenolics in FST products. TPC was significantly higher (p < 0.05) in FST than FS, in the order of green tea > oolong tea > black tea > soymilk. The FSTs were effective at scavenging DPPH-radical rather than hydroxyl radical. Optimal pH to stabilize TPs in SMT was ca. 5.7, which reduced total TP loss by ca. 40% compared with that obtained from products with TE supplemented at the beginning of fermentation. A gradual decrease in TPs was observed during storage (4 C), with more than half of total TPs remained in FST after 8 weeks.

Original languageEnglish
Pages (from-to)262-269
Number of pages8
JournalFood Chemistry
Volume158
DOIs
Publication statusPublished - 1 Sep 2014
Externally publishedYes

Keywords

  • Antioxidant capacity
  • HPLC
  • pH stability
  • Soymilk fermentation
  • Tea polyphenol

ASJC Scopus subject areas

  • Analytical Chemistry
  • Food Science

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