Antimicrobial effect of rosemary extracts.
A rosemary extract commercially exploited (Oxy'less) as an antioxidant of lipids in foods was dissolved in ethanol (100 mg/ml), and the solution was tested against foodborne microorganisms. For gram-positive bacteria, the MIC of the ethanolic solution was 1% for Leuconostoc mesenteroides, 0.5% for Listeria monocytogenes, 0.5% for Staphylococcus aureus, 0.13% for Streptococcus mutans, and 0.06% for Bacillus cereus. It slowed the growth of Penicillium roquefortii and Botrytis cinerea. Up to 1% of the ethanolic solution had no activity on the gram-negative bacteria Escherichia coli, Salmonella Enteritidis, and Erwinia carotovora and on the yeasts Rhodotorula glutinis and Cryptococcus laurentii. Antibacterial activity of the rosemary extract was strongly influenced by the composition of the media. The MIC was reduced by low pH, high NaCl contents, and low temperatures. Low pH and high NaCl concentration had a synergistic effect on the MIC of the rosemary extract for S. aureus. Lipids, surface-active agents, and some proteins decreased its antibacterial activity, whereas pectin had no effect. The inhibitory effect was little modified by heat treatment (100 degrees C). The natural microflora of pasteurized zucchini broth was inhibited by 0.5% of the rosemary extract. The antibacterial activity was linked to the compounds extracted with hexane, which are presumably phenolic diterpenoids.
Del Campo
J
J
Institut National de la Recherche Agronomique, Station de Technologie des Produits Végétaux, Domaine Saint-Paul, Avignon, France.
Amiot
M J
MJ
Nguyen-The
C
C
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D015169:Colony Count, Microbial; D004357:Drug Synergism; D005506:Food Contamination; D005516:Food Microbiology; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000187:drug effects* / Q000254:growth & development; D006863:Hydrogen-Ion Concentration; D019686:Lamiaceae; D008826:Microbial Sensitivity Tests; D010936:Plant Extracts / Q000037:antagonists & inhibitors / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors; D014867:Water; D015003:Yeasts / Q000187:drug effects* / Q000254:growth & development
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D010936:Plant Extracts; D014867:Water; D012965:Sodium Chloride