title: Optimization of ultrasound-assisted extraction of antioxidant compounds from Tunisian Zizyphus lotus fruits using response surface methodology.
abstract: The optimization of antioxidant extraction conditions from a ripe edible fruits of Zizyphus lotus (L.) with an ultrasound-assisted system was achieved by response surface methodology. The central composite rotatable design was employed for optimization of extraction parameters in terms of total phenolic content and antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and phosphomolybdenum assay. The optimum operating conditions for extraction were as follows: ethanol concentration, 50%; extraction time, 25 min; extraction temperature, 63°C and ratio of solvent to solid, 67 mL/g. Under these conditions, the obtained extract exhibited a high content of phenolic compounds (40.782 mg gallic acid equivalents/g dry matter) with significant antioxidant properties (the total antioxidant activity was 75.981 mg gallic acid equivalents/g dry matter and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity was 0.289 mg/mL).
authors: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj- Cédria, BP 901, 2050 Hammam-lif, Tunisia. Electronic address: Khaoulafayrouzahammi@gmail.com.
authors: Khaoula Mkadmini
authors: KM
authors: Hammi
authors: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj- Cédria, BP 901, 2050 Hammam-lif, Tunisia.
authors: Ahmed
authors: A
authors: Jdey
authors: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj- Cédria, BP 901, 2050 Hammam-lif, Tunisia.
authors: Chedly
authors: C
authors: Abdelly
authors: Laboratoire des Interfaces et des Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Université de Monastir, Bd. de l'environnement, 5019 Monastir, Tunisia.
authors: Hatem
authors: H
authors: Majdoub
authors: Laboratoire des Plantes Extrêmophiles, Centre de Biotechnologie de Borj- Cédria, BP 901, 2050 Hammam-lif, Tunisia.
authors: Riadh
authors: R
authors: Ksouri
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification*; D001713:Biphenyl Compounds / Q000737:chemistry; D016166:Free Radical Scavengers / Q000302:isolation & purification; D005638:Fruit / Q000737:chemistry; D005707:Gallic Acid / Q000032:analysis; D010636:Phenols / Q000032:analysis; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000032:analysis; D014465:Ultrasonics / Q000379:methods; D031957:Ziziphus / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D005707:Gallic Acid; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity; Central composite rotatable design; Optimization; Phosphomolybdenum assay; Response surface methodology; Total phenolic content; Ultrasound-assisted system