Acidic degradation and enhanced antioxidant activities of exopolysaccharides from Cordyceps sinensis mycelial culture

Jing Kun Yan, Lin Li, Zhao Mei Wang, Po Hong Leung, Wen Qiang Wang, Jianyong Wu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

58 Citations (Scopus)

Abstract

An exopolysaccharide (EPS) fraction isolated from mycelial culture of a Cordyceps sinensis fungus, designated EPS-1 with an average molecular weight (MW) of 38 kDa, was hydrolysed in dilute sulphuric acid solution at pH 1 and 90 °C, yielding two major MW fractions, 3.0 kDa and 30 kDa, respectively. While the proportion of lower MW fraction increased with the hydrolysis period (18% in 0.5 h and 92% in 10 h), the polydispersity (Mw/Mn) of EPS decreased steadily (from 1.47 initially to 1.10 in 10 h). The IR spectra of hydrolysed EPS fractions showed changes only in the C-O-C and C-O-H band peaks from that of EPS-1. These results suggest that the hydrolysis of EPS in the acidic solution caused the EPS degradation mainly by cleaving the glycosidic linkage but no change in the primary molecular structure. The hydrolysed EPS fractions had much higher (30-80%) antioxidant and radical-scavenging activities.
Original languageEnglish
Pages (from-to)641-646
Number of pages6
JournalFood Chemistry
Volume117
Issue number4
DOIs
Publication statusPublished - 15 Dec 2009

Keywords

  • Antioxidant activity
  • Hydrolysis
  • Medicinal fungus
  • Molecular weight
  • Polysaccharides
  • Radical scavenging

ASJC Scopus subject areas

  • Analytical Chemistry
  • Food Science
  • Medicine(all)

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