title: Analysis of total contents of hydroxytyrosol and tyrosol in olive oils.
abstract: The most abundant phenolic compounds in olive oils are the phenethyl alcohols hydroxytyrosol and tyrosol. An optimized method to quantify the total concentration of these substances in olive oils has been described. It consists of the acid hydrolysis of the aglycons and the extraction of phenethyl alcohols with a 2 M HCl solution. Recovery of the phenethyl alcohols from oils was very high (<1% remained in the extracted oils), and the limits of quantification (LOQ) were 0.8 and 1.4 mg/kg for hydroxytyrosol and tyrosol, respectively. Precision values, both intraday and interday, remained below 3% for both compounds. The final optimized method allowed for the analysis of several types of commercial olive oils to evaluate their hydroxytyrosol and tyrosol contents. The results show that this method is simple, robust, and reliable for a routine analysis of the total concentration of these substances in olive oils.
authors.affiliation: Food Biotechnology Department, Instituto de la Grasa (IG-CSIC), Avenida Padre García Tejero 4, 41012 Seville, Spain.
authors.forename: Concepción
authors.initials: C
authors.lastname: Romero
authors.forename: Manuel
authors.initials: M
authors.lastname: Brenes
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D059625:Liquid-Liquid Extraction / Q000379:methods; D031658:Olea / Q000737:chemistry*; D000069463:Olive Oil; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives* / Q000032:analysis / Q000302:isolation & purification; D010938:Plant Oils / Q000032:analysis*
chemical_list: D000069463:Olive Oil; D010938:Plant Oils; C005975:3,4-dihydroxyphenylethanol; C011867:4-hydroxyphenylethanol; D010626:Phenylethyl Alcohol