title: Obtaining sugars and natural antioxidants from olive leaves by steam-explosion.
abstract: In this work, steam-explosion treatment was evaluated as a procedure to recover sugars and natural antioxidants from olive tree leaves. The treatment was carried out following a Box-Behnken experimental design, with three factors, temperature (180-220°C), process time (2-10min) and milling time (0-15s). Response surface methodology showed that temperature was the most influential factor, followed by process time, while the best results were achieved with whole leaves. The operational conditions for simultaneously maximizing the sugars and natural antioxidants recoveries resulted to be 180°C, 8.3min and whole leaf; under these conditions 18.39g and 1950mg were obtained from 100g dry olive leaves, respectively. This is equivalent to 70% recovery of the initial sugars present in olive leaves, with a very low formation of inhibitory compounds and an important amount of natural products with antioxidant capacity such as oleuropein, hydroxytyrosol and flavonoids.
authors.affiliation: Department of Chemical, Environmental and Materials Engineering, Agrifood Campus of International Excellence (ceiA3), Universidad deJaén, 23071 Jaén, Spain.
authors.forename: Juan Miguel
authors.initials: JM
authors.lastname: Romero-García
authors.affiliation: Department of Food Phytochemistry, Instituto de la Grasa, CSIC, Ctra. de Utrera, km.1, Pablo de Olavide University Campus, Building 46, 41013 Seville, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lama-Muñoz
authors.affiliation: Department of Food Phytochemistry, Instituto de la Grasa, CSIC, Ctra. de Utrera, km.1, Pablo de Olavide University Campus, Building 46, 41013 Seville, Spain.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Rodríguez-Gutiérrez
authors.affiliation: Department of Chemical, Environmental and Materials Engineering, Agrifood Campus of International Excellence (ceiA3), Universidad deJaén, 23071 Jaén, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Moya
authors.affiliation: Department of Chemical, Environmental and Materials Engineering, Agrifood Campus of International Excellence (ceiA3), Universidad deJaén, 23071 Jaén, Spain.
authors.forename: Encarnación
authors.initials: E
authors.lastname: Ruiz
authors.affiliation: Department of Food Phytochemistry, Instituto de la Grasa, CSIC, Ctra. de Utrera, km.1, Pablo de Olavide University Campus, Building 46, 41013 Seville, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Fernández-Bolaños
authors.affiliation: Department of Chemical, Environmental and Materials Engineering, Agrifood Campus of International Excellence (ceiA3), Universidad deJaén, 23071 Jaén, Spain. Electronic address: ecastro@ujaen.es.
authors.forename: Eulogio
authors.initials: E
authors.lastname: Castro
mesh_terms: D000606:Amino Sugars / Q000737:chemistry*; D000975:Antioxidants / Q000032:analysis / Q000737:chemistry*; D031658:Olea / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D013227:Steam / Q000032:analysis*
chemical_list: D000606:Amino Sugars; D000975:Antioxidants; D013227:Steam
keywords: Biorefinery; Natural antioxidants; Oligomers; Olive leaves; Steam-explosion; Sugars