abstract
This study aimed to assess the lipophilic and phenolic extractives composition of cork of Quercus suber L. grown in Algeria by gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatograhy-mass spectrometry (UHPLC-MS), respectively. The phenolic cork oak extract was also evaluated for its scavenging activity towards DPPH radical, ABTS radical scavenging, reducing power and antibacterial activity against Staphylococcus aureus ATCC, Listeria innocua, Escherichia coil and Pseudomonas aeruginosa. The lipophilic fraction is mainly composed of thirty three compounds, with cerine, friedeline and betulinic acid as the major components. Furthermore, eighteen phenolic compouds were detected in the phenolic extract, with protocatechuic, ellagic and gallic acids as the major compounds. The methanol:water cork extract showed high DPPH scavenging ability with an ICso value of 5.69 mu g mL(-1) and an ABTS enhanced scavenging capacity when compared to BHT and trolox. A reducing power higher than BHA was also found. In addition, the phenolic fraction of cork was shown to inhibit the growth of Staphelococcus aureus (12.1 mm) and Pseudomonas aeroginisa (10.07 mm). These results indicate that algerian cork oak constitutes a good source of natutal bioactive compounds. Morever, this study is a relevant contribution to the valorization of algerian cork industrial residues, for which novel applications could be considered, namely the use of these extracts in food or nutraceutical industry. (C) 2015 Elsevier B.V. All rights reserved.
keywords
PERFORMANCE LIQUID-CHROMATOGRAPHY; DIFFERENT MORPHOLOGICAL PARTS; ANTIOXIDANT ACTIVITY; ANTIBACTERIAL ACTIVITIES; CHEMICAL-COMPOSITION; MASS-SPECTROMETRY; REPRODUCTION CORK; ELLAGIC ACID; GALLIC ACID; BY-PRODUCTS
subject category
Agriculture
authors
Touati, R; Santos, SAO; Rocha, SM; Belhamel, K; Silvestre, AJD
our authors
Armando Jorge Domingues Silvestre
Full professor
Sónia Andreia Oliveira Santos
Assistant Researcheracknowledgements
The authors wish to thank to FCT-Portugal (Fundacao para a Ciencia e Tecnologia) and POPH/FSE for the postdoctoral grants to S. A. O. Santos (SFRH/BPD/84226/2012), for CICECO-Aveiro Institute of Materials (FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement and QOPNA (PEst-C/QUI/UI0062/2013 and FCOMP-01-0124-FEDER-037296). R. Touati gratefully acknowledges the financial support as grant from Ministry of Higher Education and Scientific Research of Algeria. The authors are also grateful to Dr. Farida BENDALI and Mr. Hamza AIT SEDDIK from Applied microbiology Laboratory for assistance with antibacterial tests.