Biorefining of Cymbopogon nardus from Reunion Island into essential oil and antioxidant fractions by conventional and high pressure extraction methods

• Published in: Industrial crops and products Vol. 126; pp. 158 - 167
• Main Authors: Clain, Elodie, Baranauskienė, Renata, Kraujalis, Paulius, Šipailienė, Aušra, Maždžierienė, Ramutė, Kazernavičiūtė, Rita, El Kalamouni, Chaker, Venskutonis, Petras Rimantas
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2018
• Subjects: Antibacterial capacity; Antioxidant capacity; Cymbopogon nardu; Pressurized liquid extraction; Sessential oil; Supercritical fluid extraction; Antioxidant capacity; Pressurized liquid extraction; Antibacterial capacity; Cymbopogon nardu; Supercritical fluid extraction; Sessential oil
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2018.10.015

•Cymbopogon nardus was biorefined by several methods with different solvents.•Liquid distillation residue was freeze-dried; the solids were extracted with acetone.•Soxhlet, supercritical carbon dioxide and pressurized liquid extraction applied.•Antioxidant potential of C. nardus was evaluated by the in vitro assays.•The plant valorized as a source of antioxidant and anticbacterial products. Steam distilled essential oil of Cymbopogon nardus has been widely studied and commercialized; however, comprehensive valorisation of plant material requires more systematic characterization of other, non-volatile extracts and their potential activities. For this purpose C. nardus herb was fractionated into essential oil (EO) and non-volatile fractions by hydrodistillation (HD), Soxhlet (S), supercritical CO2 (SFE-CO2) and pressurized liquid (PLE) extractions. Antioxidant potential was evaluated by total phenolics (TPC), DPPH•/ABTS•+ scavenging and oxygen radical absorbance (ORAC) capacity. The yields were from 1.37/1.39% for SFE-CO2 (50 °C)/HD to 12.2/12.6% (w/w) for PLE-water/freeze dried after EO-HD water (PLE-WE/FD-WE). TPC was higher in S-acetone (S-AE) and PLE-WE, 70 and 60 mg of gallic acid equivalents (GAE)/g dew (dry extract weight), respectively. S-AE and S-ethanol extracts were strongest antioxidants, on average equivalent to 770 μmol of trolox equivalents (TE)/g dew in ABTS assay. Antibacterial activity was tested by well agar diffusion and minimal inhibitory concentration (MIC) methods with various microorganisms; EO at 3% inhibited all bacteria, except for S. aureus and S. typhimurium; MICs were in the range of 0.39–12.5 mg/mL. C. nardus extracts may be considered as potential natural antioxidants and antibacterial agents and a good source of phenolics.