Abstract: Objective To extract and purify pomegranate peel polyphenols, and to study its effect on streptococcus mutans. Methods Resin adsorption method was used to purify ethanolic extract to polyphenols. The purity of pomegranate peel polyphenols was tested by Foline-phenol method. Broth dilution test was used to study the antibacterial effort of polyphenols and its effect on bacterial acidogenicity. Results The purity of pomegranate peel polyphenols was 82.03%. The minimal inhibitory concentration (MIC) was 0.5 μg/L and the minimal bactericidal concentration (MBC) was 1.0 g/L. With the increasing concentrations of polyphenols, the acidogenicity capacity of bacteria was decreasing. Conclusion Pomegranate peel polyphenols has a potential effect on antibacteria.

Key words: Pomegranate peel, Polyphenol, Streptococcus mutans, Gallic acid, Antibacteria