title: Influence of pH on the antioxidant phenols solubilised from hydrothermally treated olive oil by-product (alperujo).
abstract: The application of a novel industrial process based on the hydrothermal treatment of olive oil waste (alperujo) led to a final liquid phase that contained a high concentration of simple phenolic compounds. In this study the effect of pH on phenol extraction with ethyl acetate from the aqueous phase of hydrothermally treated alperujo at 160°C/60min (without modification, pH 4.5, and adjusted to pH 2.5) was evaluated, beside the increase of hydroxytyrosol during the storage. The variation of the concentration of phenolic compounds in each extract was analyzed by HPLC. The phenolic extract obtained at pH 4.5 presented a higher proportion of total and individual phenols and better antioxidant capacity in vitro than the extract obtained at pH 2.5. The use of lower pH values enhances the concentration of hydroxytyrosol in the liquid diminishing the storage times.
authors.affiliation: Food Phytochemistry Department, Instituto de la Grasa, Spanish National Research Council (CSIC), Campus Universitario Pablo de Olavide - Edificio 46, Ctra. de Utrera, km. 1, 41013 Seville, Spain.
authors.forename: Fátima
authors.initials: F
authors.lastname: Rubio-Senent
authors.affiliation: Food Phytochemistry Department, Instituto de la Grasa, Spanish National Research Council (CSIC), Campus Universitario Pablo de Olavide - Edificio 46, Ctra. de Utrera, km. 1, 41013 Seville, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Fernández-Bolaños
authors.affiliation: Food Phytochemistry Department, Instituto de la Grasa, Spanish National Research Council (CSIC), Campus Universitario Pablo de Olavide - Edificio 46, Ctra. de Utrera, km. 1, 41013 Seville, Spain.
authors.forename: Aránzazu
authors.initials: A
authors.lastname: García-Borrego
authors.affiliation: Food Phytochemistry Department, Instituto de la Grasa, Spanish National Research Council (CSIC), Campus Universitario Pablo de Olavide - Edificio 46, Ctra. de Utrera, km. 1, 41013 Seville, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lama-Muñoz
authors.affiliation: Food Phytochemistry Department, Instituto de la Grasa, Spanish National Research Council (CSIC), Campus Universitario Pablo de Olavide - Edificio 46, Ctra. de Utrera, km. 1, 41013 Seville, Spain. Electronic address: guirogu@cica.es.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Rodríguez-Gutiérrez
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D000069463:Olive Oil / Q000737:chemistry*; D010636:Phenols / Q000032:analysis*; D010626:Phenylethyl Alcohol / Q000031:analogs & derivatives / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D000069463:Olive Oil; D010636:Phenols; D010936:Plant Extracts; C005975:3,4-dihydroxyphenylethanol; D010626:Phenylethyl Alcohol
keywords: Alperujo; Antioxidant; Ethyl acetate extract; Hydroxytyrosol; Olive oil wastes; Phenols