title: Extraction of Antioxidants from Borage (Borago officinalis L.) Leaves-Optimization by Response Surface Method and Application in Oil-in-Water Emulsions.
abstract: Borage (Borago officinalis L.) is a typical Spanish plant. During processing, 60% are leaves. The aim of this work is to model and optimize the extraction of polyphenol from borage leaves using the response surface method (RSM) and to use this extract for application in emulsions. The responses were: total polyphenol content (TPC), antioxidant capacity by ORAC, and rosmarinic acid by HPLC. The ranges of the variables temperature, ethanol content and time were 50-90 °C, 0%-30%-60% ethanol (v/v), and 10-15 min. For ethanolic extraction, optimal conditions were at 75.9 °C, 52% ethanol and 14.8 min, yielding activity of 27.05 mg GAE/g DW TPC; 115.96 mg TE/g DW in ORAC and 11.02 mg/L rosmarinic acid. For water extraction, optimal activity was achieved with extraction at 98.3 °C and 22 min, with responses of 22.3 mg GAE/g DW TPC; 81.6 mg TE/g DW in ORAC and 3.9 mg/L rosmarinic acid. The significant variables were ethanol concentration and temperature. For emulsions, the peroxide value was inhibited by 60% for 3% extract concentration; and 80% with 3% extract concentration and 0.2% of BSA. The p-anisidine value between the control and the emulsion with 3% extract was reduced to 73.6% and with BSA 86.3%, and others concentrations had similar behavior.
authors.affiliation: Department of Chemical Engineering, Technical University of Catalonia, Avda. Diagonal 647, Barcelona 08028, Spain. segoviafj@gmail.com.|Department of Chemical Engineering, Antonio José de Sucre National Experimental Polytechnic University, Avenida Corpahuaico, Barquisimeto 3001, Venezuela. segoviafj@gmail.com.
authors.forename: Francisco
authors.initials: F
authors.lastname: Segovia
authors.affiliation: Department of Agro-industrial Engineering, Lisandro Alvarado Central Western University, Avenida Florencio Jiménez, Km 1, Barquisimeto 3001, Venezuela. bryshilalupo@ucla.edu.ve.
authors.forename: Bryshila
authors.initials: B
authors.lastname: Lupo
authors.affiliation: Department of Chemical Engineering, Technical University of Catalonia, Avda. Diagonal 647, Barcelona 08028, Spain. sapeisa@yahoo.es.
authors.forename: Sara
authors.initials: S
authors.lastname: Peiró
authors.affiliation: Department of Food and Nutritional Sciences, University of Reading, Whiteknights P.O. Box 226, Reading RG6 6AP, UK. m.h.gordon@reading.ac.uk.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Gordon
authors.affiliation: Department of Chemical Engineering, Technical University of Catalonia, Avda. Diagonal 647, Barcelona 08028, Spain. m.pilar.almajano@upc.edu.
authors.forename: María Pilar
authors.initials: MP
authors.lastname: Almajano
keywords: ORAC; RSM; borage leaves; emulsion; extraction; oxidation; rosmarinic acid