title: Optimization of microwave-assisted extraction of polyphenols from Myrtus communis L. leaves.
abstract: Phytochemicals, such as phenolic compounds, are of great interest due to their health-benefitting antioxidant properties and possible protection against inflammation, cardiovascular diseases and certain types of cancer. Maximum retention of these phytochemicals during extraction requires optimised process parameter conditions. A microwave-assisted extraction (MAE) method was investigated for extraction of total phenolics from Myrtus communis leaves. The total phenolic capacity (TPC) of leaf extracts at optimised MAE conditions was compared with ultrasound-assisted extraction (UAE) and conventional solvent extraction (CSE). The influence of extraction parameters including ethanol concentration, microwave power, irradiation time and solvent-to-solid ratio on the extraction of TPC was modeled by using a second-order regression equation. The optimal MAE conditions were 42% ethanol concentration, 500 W microwave power, 62 s irradiation time and 32 mL/g solvent to material ratio. Ethanol concentration and liquid-to-solid ratio were the significant parameters for the extraction process (p<0.01). Under the MAE optimised conditions, the recovery of TPC was 162.49 ± 16.95 mg gallic acidequivalent/gdry weight(DW), approximating the predicted content (166.13 mg GAE/g DW). When bioactive phytochemicals extracted from Myrtus leaves using MAE compared with UAE and CSE, it was also observed that tannins (32.65 ± 0.01 mg/g), total flavonoids (5.02 ± 0.05 mg QE/g) and antioxidant activities (38.20 ± 1.08 μg GAE/mL) in MAE extracts were higher than the other two extracts. These findings further illustrate that extraction of bioactive phytochemicals from plant materials using MAE method consumes less extraction solvent and saves time.
authors: Laboratory of Biomathematics, Biochemistry, Biophysics and Scientometrics, Abderrahmane Mira University of Bejaia, Bejaia 06000, Algeria.
authors: Farid
authors: F
authors: Dahmoune
authors: Food Science and Human Nutrition, School of Food and Agriculture, University of Maine, Orono, ME 04469, United States. Electronic address: balunkeswar.nayak@maine.edu.
authors: Balunkeswar
authors: B
authors: Nayak
authors: Laboratory of Biomathematics, Biochemistry, Biophysics and Scientometrics, Abderrahmane Mira University of Bejaia, Bejaia 06000, Algeria.
authors: Kamal
authors: K
authors: Moussi
authors: Laboratory of Biomathematics, Biochemistry, Biophysics and Scientometrics, Abderrahmane Mira University of Bejaia, Bejaia 06000, Algeria.
authors: Hocine
authors: H
authors: Remini
authors: Laboratory of Biomathematics, Biochemistry, Biophysics and Scientometrics, Abderrahmane Mira University of Bejaia, Bejaia 06000, Algeria.
authors: Khodir
authors: K
authors: Madani
mesh_terms: D000975:Antioxidants / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D000431:Ethanol / Q000737:chemistry; D005419:Flavonoids / Q000032:analysis; D008855:Microscopy, Electron, Scanning; D008872:Microwaves; D031651:Myrtus / Q000737:chemistry*; D064209:Phytochemicals / Q000032:analysis; D010936:Plant Extracts / Q000032:analysis; D018515:Plant Leaves / Q000737:chemistry*; D059808:Polyphenols / Q000032:analysis*; D015203:Reproducibility of Results; D012997:Solvents / Q000737:chemistry; D013634:Tannins / Q000032:analysis; D014465:Ultrasonics
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D064209:Phytochemicals; D010936:Plant Extracts; D059808:Polyphenols; D012997:Solvents; D013634:Tannins; D000431:Ethanol
keywords: Antioxidant activity; Microwave extraction; Myrtus leaves; Phenolic compounds; Response surface method; Ultrasound extraction