The main objective of this study was the screening of some selected aromatic plants very popular in Greece, with respect to their total phenolic content, antioxidant capacity, reducing activity, and oxidative stability. All plants were extracted with the conventional method, reflux with methanol. The essential oils of the plants were also analyzed for their antioxidant properties. The total phenolic content was determined by the Folin-Ciocalteu method using gallic acid as the standard, while the phenolic substances were identified and quantified by High Performance Liquid Chromatography (HPLC) coupled with a multi-wavelength ultraviolet-visible (UV-vis) detector. The antioxidant capacity of the plant extracts was measured by their ability to scavenge free radicals such as (a) DPPH (2,2-diphenyl-1-picrylhydrazyl) and, (b) ABTS (2,2′-azinobis-(3-ethylbenzothiaziline-6- sulfonate). The Folin-Ciocalteu method proved the existence of antioxidants in the aromatic plant extracts. Taking into account the results of the DPPH and ABTS methods, the free radical scavenging capacity was confirmed. Eventually, all plants exhibited low but noticeable protection levels against lipid oxidation, as determined by the Rancimat test.
References
[1]
Justesen, U.; Knuthsen, P. Composition of flavonoids in fresh herbs and calculation of flavonoid intake by use of herbs in traditional Danish dishes. Food Chem. 2001, 73, 245–250, doi:10.1016/S0308-8146(01)00114-5.
[2]
Halliwell, B.; Guteridge, J.M.C. Free Radicals in Biology and Medicine, 2nd ed.; Clarendon Press: Oxford, UK, 1989.
[3]
K？hk？nen, M.P.; Hopia, A.I.; Heikki, J.V.; Rauha, J.P.; Pihlaja, K.; Kujala, T.S.; Heinonen, M. Antioxidant activity of plant extracts containing phenolic compounds. J. Agric. Food Chem. 1999, 47, 3954–3962, doi:10.1021/jf990146l.
[4]
Rice-Evans, C.A.; Packer, L. Flavonoids in Health and Disease, 2nd ed.; Marcel Dekker Inc.: New York, NY, USA, 1998.
[5]
Rauha, J.P.; Remes, S.; Heinonen, M.; Hopia, A.; K？hk？nen, M.; Kujala, T.; Pihlaja, K.; Vuolera, H.; Vuolera, P. Antimicrobial effects of Finnish plant extracts containing flavonoids and other phenolic compounds. Int. J. Food Microbiol. 2000, 56, 3–12, doi:10.1016/S0168-1605(00)00218-X.
[6]
Hollman, P.C.H.; Hertog, M.G.L.; Katan, M.B. Analysis and health effects of flavonoids. Food Chem. 1996, 57, 43–46, doi:10.1016/0308-8146(96)00065-9.
[7]
Blois, M.S. Antioxidant determinations by the use of a stable free radical. Nature 1958, 181, 1199–1200, doi:10.1038/1811199a0.
[8]
Gardeli, C.; Papageorgiou, V.; Mallouchos, A.; Kibouris, T.; Komaitis, M. Essential oil composition of Pistacia lentiscus L. and Myrtus communis L.: Evaluation of antioxidant capacity of methanolic extracts. Food Chem. 2008, 107, 1120–1130.
[9]
Exarchou, V.; Nenadis, N.; Tsimidou, M.; Gerothanassis, I.P.; Troganis, A.; Boskou, D. Antioxidant activities and phenolic composition of extracts from Greek oregano, Greek sage, and summer savory. J. Agric. Food Chem. 2002, 50, 5294–5299.
[10]
Bantoniene, D.; Pukalskas, A.; Venskutonis, P.R.; Gruzdiene, D. Preliminary screening of antioxidant activity of some plant extracts in rapeseed oil. Food Res. Int. 2000, 33, 785–791, doi:10.1016/S0963-9969(00)00084-3.
[11]
Suárez, B.; Picinelli, A.; Mangas, J.J. Solid-phase extraction and high-performance liquid chromatographic determination of polyphenols in apple musts and ciders. J. Chromatogr. 1996, 727, 203–209, doi:10.1016/0021-9673(95)01175-7.
[12]
Proestos, C.; Boziaris, I.S.; Nychas, G.-J.E.; Komaitis, M. Analysis of flavonoids and phenolic acids in Greek aromatic plants: Investigation of their antioxidant capacity and antimicrobial activity. Food Chem. 2006, 95, 664–671, doi:10.1016/j.foodchem.2005.01.049.
[13]
Turkmen, N.; Sari, F.; Velioglu, Y.S. Effects of extraction solvents on concentration and antioxidant activity of black and black mate tea polyphenols determined by ferrous tartrate and Folin-Ciocalteu methods. Food Chem. 2006, 99, 835–841, doi:10.1016/j.foodchem.2005.08.034.
[14]
Viuda-Martos, M.; Navajas, Y.R.; Zapata, E.S.; Fernández-López, J.; Pérez-álvarez, J.A. Antioxidant activity of essential oils of five spice plants widely used in a Mediterranean diet. Flavour Fragr. J. 2009, 25, 13–19.
[15]
Atoui, A.K.; Mansouri, A.; Boskou, G.; Kefalas, P. Tea and herbal infusions: Their antioxidant activity and phenolic profile. Food Chem. 2005, 89, 27–36, doi:10.1016/j.foodchem.2004.01.075.
[16]
Miliauskas, G.; Venskutonis, P.R.; van Beek, T.A. Screening of radical scavenging activity of some medicinal and aromatic plant extracts. Food Chem. 2004, 85, 231–237, doi:10.1016/j.foodchem.2003.05.007.
[17]
Proestos, C. Determination of Phenolic Compounds in Aromatic Plants. Ph.D Thesis, Agricultural University of Athens, Athens, Greece.
[18]
Kintzios, S.; Papageorgiou, K.; Yiakoumettis, I.; Baricevi, D.; Kusar, A. Evaluation of the antioxidants activities of four Slovene medicinal plant species by traditional and novel biosensory assays. J. Pharm. Biomed. Anal. 2010, 53, 773–776, doi:10.1016/j.jpba.2010.05.013.
[19]
Aruoma, O.; Spencer, J.P.; Rossi, R.; Aeschbach, R.; Khan, A.; Mahmood, N.; Munoz, A.; Murcia, A.; Butler, J.; Halliwell, B. An evaluation of the antioxidant and antiviral action of extracts of rosemary and provencal herbs. Food Chem. Toxicol. 1996, 34, 449–456, doi:10.1016/0278-6915(96)00004-X.
[20]
Nuutila, A.M.; Kammiovirta, K.; Oksman-Caldentey, K.M. Comparison of methods for the hydrolysis of flavonoids and phenolic acids from onion and spinach for HPLC analysis. Food Chem. 2002, 76, 519–525, doi:10.1016/S0308-8146(01)00305-3.
[21]
Justesen, U.; Knuthsen, P.; Torben, T.J. Quantitative analysis of flavonols, flavones, and flavanones in fruits, vegetables and beverages by high-performance liquid chromatography with photo-diode array and mass spectrometric detection. J. Chromatogr. 1998, 799, 101–110, doi:10.1016/S0021-9673(97)01061-3.
[22]
Finger, A.; Kuhr, S.; Engelhardt, H.U. Chromatography of tea constituents. J. Chromatogr. 1992, 624, 293–315, doi:10.1016/0021-9673(92)85685-M.
[23]
Lee, S.H.; Widmer, W.B. Handbook of Food Analysis, 1st ed.; Marcel Dekker Inc.: New York, NY, USA, 1996.
[24]
Proestos, C.; Chorianopoulos, N.; Nychas, G.J.E.; Komaitis, M. RP-HPLC analysis of the phenolic compounds of plant extracts. Investigation of their antioxidant capacity and antimicrobial activity. J. Agric. Food Chem. 2005, 53, 1190–1195.
[25]
Proestos, C.; Sereli, D.; Komaitis, M. Determination of phenolic compounds in aromatic plants by RP-HPLC and GC-MS. Food Chem. 2006, 95, 44–52, doi:10.1016/j.foodchem.2004.12.016.
