title: Antibacterial effects of roselle calyx extracts and protocatechuic acid in ground beef and apple juice.
abstract: The antibacterial effects of roselle calyx aqueous and ethanol extracts and protocatechuic acid against food spoilage bacteria Salmonella typhimurium DT104, Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus were examined. Minimal inhibitory concentrations of roselle calyx aqueous and ethanol extracts and protocatechuic acid against these bacteria were in the range of 112-144, 72-96, and 24-44 microg/mL, respectively. Protocatechuic acid content in roselle calyx aqueous and ethanol extracts was 2.8 +/- 0.7 and 11.9 +/- 1.2 mg/g, respectively. Antibacterial activity of roselle calyx ethanol extract and protocatechuic acid was not affected by heat treatments from 25 degrees to 75 degrees C and 25 degrees to 100 degrees C, respectively. After 3 days storage at 25 degrees C, the addition of roselle calyx extracts and protocatechuic acid exhibited dose-dependent inhibitory effects against test bacteria in ground beef and apple juice, in which the roselle calyx ethanol extract showed greater antibacterial effects than the aqueous extract. These data suggest that roselle calyx ethanol extract and protocatechuic acid might be potent agents as food additives to prevent contamination from these bacteria.
authors.affiliation: Department of Health and Nutrition Biotechnology, Asia University, Taichung County, Taiwan.
authors.forename: Che-Yi
authors.initials: CY
authors.lastname: Chao
authors.forename: Mei-Chin
authors.initials: MC
authors.lastname: Yin
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001409:Bacillus cereus / Q000187:drug effects; D001628:Beverages / Q000382:microbiology*; D002417:Cattle; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial; D019453:Escherichia coli O157 / Q000187:drug effects; D005519:Food Preservation / Q000379:methods*; D005520:Food Preservatives / Q000494:pharmacology; D031584:Hibiscus / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D062385:Hydroxybenzoates / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000187:drug effects; D027845:Malus; D008461:Meat Products / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000494:pharmacology; D012486:Salmonella typhimurium / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D005520:Food Preservatives; D062385:Hydroxybenzoates; D010936:Plant Extracts; C009091:protocatechuic acid