Abstract:

Polysaccharides in blueberry fruits were extracted by water extraction and ethanol precipitation, and after preliminary purification, the precipitate was assessed for its antioxidant and antimicrobial activities. The results showed that blueberry polysaccharides had a strong ability to scavenge both hydroxyl and DPPH free radicals, with IC50 values of 2 mg/mL and 7 mg/mL. However, almost no scavenging effect against superoxide anion radicals was observed. The polysaccharides could inhibit the growth of all of the following microorganisms: Bacillus subtilis, Escherichia coli, Staphylosocus aureus, and Saccharomyces cerevisiae and the corresponding minimal inhibitory concentrations (MIC) varied from 50 to 75 mg/mL. However, no inhibitory effect on G.tropicalis, Penicillium sp. or Aspergillus niger was observed.

Key words: blueberry polysaccharide, antioxidant activity, antimicrobial activity