title: Antimicrobial activity of hydroxytyrosol: a current controversy.
abstract: This study focus on the main factors that affect the antimicrobial capacity of hydroxytyrosol, including the concentration (200, 400, and 1000 μg/mL), target strains, and the culture media (nutrient-rich and less-rich culture media). The potential HT degradation was also evaluated by HPLC-PAD. Kinetic parameters from growth curves showed that HT concentrations produced a doses-dependent shift when compared to the untreated control. In most of the cases, the highest tested dose (1000 μg/mL) was needed to inhibit growth of the selected strains. However, all the strains were able to grow even at the highest HT dose when cultivated in nutrient-rich culture media. It was observed that HT concentrations were reduced by about 15%, except for Escherichia coli 533 and 679 in Muller Hinton broth, where HT was reduced up to 35%. The results showed a limited antimicrobial activity, contrary to information previously published in some research papers.
authors.affiliation: a Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology , CEBAS-CSIC , Murcia , Spain.
authors.forename: María S
authors.initials: MS
authors.lastname: Medina-Martínez
authors.affiliation: a Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology , CEBAS-CSIC , Murcia , Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Truchado
authors.affiliation: a Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology , CEBAS-CSIC , Murcia , Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Castro-Ibáñez
authors.affiliation: a Research Group on Quality, Safety and Bioactivity of Plant Foods, Department of Food Science and Technology , CEBAS-CSIC , Murcia , Spain.
authors.forename: Ana
authors.initials: A
authors.lastname: Allende
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D003470:Culture Media; C005975:3,4-dihydroxyphenylethanol; D010626:Phenylethyl Alcohol
keywords: Escherichia coli; antimicrobial; growth inhibition; kinetic parameters; olive