Influence of variety and extraction solvent on antibacterial activity of roselle (Hibiscus sabdariffa L.) calyxes.

An analysis was done on the antimicrobial activity of calyx extracts from five Hibiscus sabdariffa varieties against Salmonella Typhimurium and Salmonella Choleraesuis. Calyx extracts produced with water, ethanol and methanol were applied to Salmonella cultures. All extracts exhibited antimicrobial activity against both Salmonella serotypes. The antimicrobial effect was highest in the variety named as ?Alma blanca? (in which anthocyanin production has been almost completely suppressed). Extract pH had a significant (p<0.05) impact on extract antimicrobial effect.