Antimicrobial action of purified raspberry flavonoid

Abstract

In this paper, the bacteriostatic action of purified raspberry flavonoid was explored. A study was conducted on the effect of raspberry flavonoid on Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Saccharomyces cerevisiae, Rhizopus, Mucor and Penicillium. Raspberry flavonoid had the best inhibition effect on S. aureus, followed by B. subtilis, E. coli and Penicillium. However, it cannot inhibit the growth of S. cerevisiae, Rhizopus and Mucor. The minimal inhibitory concentration was 0.16 mg/ml for E. coli, 0.08 mg/ml for B. subtilis, 0.04 mg/ml for S. aureus and 0.64 mg/ml for Penicillium. At 100°C, temperature does not have an obvious effect on the bacteriostatic action of raspberry flavonoid. The rate of inhibition increases with time and the increase of concentration of raspberry flavonoid. Raspberry flavonoid has a stable bacteriostatic action pH from 4 to 8.

Key words: Raspberry, flavonoid, bacteriostasis, Escherichia coli, Staphylococcus aureus.