205 L.) 15–18 studies on the 13,19 onites Department of Food Engineering, 2009 Society of Chemical Industry c ¨ uleyman Demirel University, 32260 Isparta, ¨ uleyman Demirel University, 32260 Isparta, Turkey essential oils and extracts include 14 The major essential oil constituent of Turkish b 12,13 . t 2009 Published online in Wiley Interscience: 16 November 2009 -pinene. Carvacrol was highest in the July harvest. The α ¨ uleyman Demirel University, 32260 Isparta, Turkey. Department of Field Crops, S Turkey Correspondence to:S Gulcan Ozkan, E-mail: [email protected] Department of Food Engineering, S O. onites This research aimed to determine the effect of harvest time inhibition of free radical scavenging activity and high levels ∗ a b rom early-season (June) harvested leaves had the highest marinic acid and acecetin were found in harvests of July and harvested during vegetative periods of growing season. in variable amountsvegetative depending period. on It different waswas reported times obtained that from of above-ground 1.9–3.0% parts day through steam ofof distillation and essential oil phenolic substances such as carvacrol andwere rosmarinic reported acid, which their antioxidant and antibacterial activities. Although limited reports wereoil found composition on during the variations vegetative of cycle, essential on the yield, chemicalof composition extracts and and antioxidant essential properties oils of oregano ( influence of harvest time on phenolic constituents and antioxidant properties were lacking. oregano is carvacrol. ging activities and reducing/antioxidant capacities were found The The 7–11 ly depending on vegetative periods of growing season. 1 12 and Sabri Erbas -terpinene and α Origanum have been b L.) leaves harvested during the months of June to September. L.) is represented in speciesisover60%, -cymene, O. onites p For conservation of natural Origanum Origanum 6 Origanum onites However, the overharvesting of 5 -terpinene, Hasan Baydar γ ; essential oil; phenolics; antioxidant properties; seasonal variation ∗ a : 205–209 www.soci.org 90 2010; Turkey is the leading country in the oregano trade

Origanum onites species in recent years. 1–4

2009 Society of Chemical Industry

In the essential oil , the content of the essential oil is mostly Origanum onites c studied and itexists has in been the amount noted of essential that oil yield an and ontogenetic composition. variability same report reveals that secondary metabolites in the exist rateofendemismamongtheTurkish and this high rate is suggestiveis that Turkey. the gene centre of J Sci Food Agric Productivity and ontogenetic variability of Turkey by 22 species or 32 taxa, 21 being endemic to Turkey. INTRODUCTION Turkey is regarded asLamiaceae an (Labiatae). important The gene center genus for the family RESULT: The maximum essentialoil were oil carvacrol, yield thymol, in the leaves appeared in the middle of July. The main components of oregano BACKGROUND: The aim ofproperties this of Turkish research oregano ( was to determine essential oil composition, phenolic constituents and antioxidant ( Abstract maximum extract yieldantioxidant was ability, expressed found as low in concentrationof providing September. 50% reducing/antioxidant capacity. Oil Twelve distilled phenolicwere found compounds f to of be oregano rosmarinic extractJune, acid were respectively. and Total identified acecetin. The phenolic and maximum contents, the ros free main radical components scaven antioxidant properties of Turkish oregano Gulcan Ozkan, composition, phenolic constituents and (www.interscience.wiley.com) DOI 10.1002/jsfa.3788 The influence of harvest time on essential oil to be highest in the July harvest. DISCUSSION: All yields, chemical compositions, free radical scavenging activitiesand and essential reducing/antioxidant oils capacities of of extracts Turkish oregano changed important Research Article Received: 26 March 2009 Revised: 14 August 2009 Accepted: 19 Augus in the world and exportationUS has $15 reached million over in 8000 recent tonnes years. and oregano from nature hasOriganum resulted in the threat of extinction of sources and production with highcultivation standard has and quality, been oregano started andyears. has Oregano is expanded used rapidly mainly inspices, in herbal recent the teas, folk production drugs of and essential beverages in oils, Turkey. variable and many factorstechniques, such geographic as and drying climatic conditions,daylight, factors distillation temperature, such water as stress duration andan of plant important growth role phase in play yield and composition of essential oils. Keywords: )was 50 Estima- mpore µ : 205–209 Origanum 21 90 45 . In addition, it (absorbance of 13 . 2010; × and from 129.10 to et al 100 1 − The antioxidant activity = 23 . 05 level. The analysis was extract). . 0 1 by Yaldiz − et al J Sci Food Agric < P O. onites and calculated according to the following 22 . et al , respectively, according to month (Table 2). While The essential oil yield increased as the plant grew 1 − Solvent gradient conditions with linear gradient herb using external calibration curves, constructed for 1 24–26 − Free radical scavenging activity was measured by the DPPH Thereducing/antioxidantcapacityoftheextractandessentialoil Table 1. Final time 3A%B% 20 28 52528303537455080100 A (solvent): acetic acid–water 95 35 (2 : 98 v/v); B (solvent): methanol. 75 45 72 60 70 62 65 70 63 75 55 80 50 20 0 performed in triplicate. 201.70 g kg formula: free radical scavenging activity control sample – absorbancesample). Extract of concentration providing sample/absorbance 50% inhibition (IC of control but it began to decrease atwas fruit-set stage. highest While in the extract September; value it was lowest in June (Table 2). The method of Lee tions were carried out in triplicate and calculated fromcurve a obtained calibration with gallic acid, and total phenolics wereas expressed gallic acid equivalent (mg GAE g size membrane filter (Vivascienceamount AG, of Hannover, Germany). phenolic The as compounds g in kg the extract was calculated RESULTS AND DISCUSSION In this study,oregano varied the from 25.00 essential to oil 32.00 g kg and extract yield of Turkish was used: solvent Asolvent consisted B was of methanol acetic andin acid–water the gradient Table (2 1. program : used 98, TheShimadzu is v/v); given data Class-VP wereSoftware integrated Chromatography and System Laboratory analyzedsolutions (Tokyo, and using mobile Automated the phases Japan). were filtered Extract using a samples, 0 standard was expressed relative to that ofwere ascorbic carried acid. out All in determinations triplicate and the results were averaged. Statistical analysis Results of theby research Duncan’s were multiple testedstatistically range for significant test. at statistical Differences the significance were considered the lowest value was obtained inthe June, at highest the essential pre-flowering oil stage, yieldthe was flowering obtained stage in and July,results beginning at were of the reported end the for of fruit-set stage. Similar each pure phenolic standard. All determinationsin were triplicate carried and out the results were averaged. Determination of totalactivity and reducing/antioxidant phenolics, capacity freeTotal radical phenolics scavenging adapted were by determined the Folin–Ciocalteu according colorimetric to method. the method species. was also indicated thatthe the beginning essential of oil the yield fruit was or the seed highest formation at stage for was evaluated by the formation of phosphomolybdenum complex according to the method of Prieto calculated from the plot ofconcentration. inhibition percentage against extract ¨ UCHI Cata in size ◦ 2 0.32 mm × 2009 Society of Chemical Industry N, longitude 60) to obtain www.soci.org G Ozkan, H Baydar, S Erbas  c 25 cm in plots 45 Reversed phase ◦ × =− C) under vacuum Cuntiluse. Landthecolumn ◦ 20 ◦ T . µ C. The temperature 40 C for 35 min. Helium C (1 min) to 220 ◦ 20 ◦ ◦ et al − < L. The identification of the T µ m) was used. The flow rate µ C using an ultrasonicated water apan), SIL-10AD vp Autosampler, ◦ L.) seeds used in this study were C. Gradient elution of two solvents m) capillary column. Detector and 6 mm, 5 ◦ . µ 4 25 × . 2nitroterephthalate (FFAP) (50 m and than held at 220 + ,injectionvolumewas10 1 1 − − Origanum onites Cmin ◦ Cuntiluse. ◦ E, altitude 997 m). Each plot in the blocks was 12.5 m  20 33 ◦ − injector temperatures were set at 240 temperature was set at 30 rate of 5 Preparation of extract Dried and powdereda 2h for herb at 40 material 100 mL (15(55:40:4.5:0.5) g) mixture was extracted of with methanol–acetone–water–acetic acid high-performance liquid chromatographyDetection (RP-HPLC) and was quantification used. wasSystem carried controller out with (Shimadzu, a J SCL-10 Avp LC-10AD vp pump,heater and DGU-14a diode array degasser, detector setXDB CTO-10 at C-18 278 column A nm. (250 An vp Agilent Eclipse column was 0.8 mL min www.interscience.wiley.com/jsfa Plant material Oregano ( MATERIALS AND METHODS Analysis of essential oil components Analyses of thea essential gas oil chromatograph–mas componentsusing spectrometer/quadropole a were detector, Shimadzu performed QPpolyethylene on glycol 5050 system (Kyoto,(i.d.), Japan), fitted film with thickness: a 0 and lyophilizers (VirTis 2K, Gradiner,crude NY, extracts. USA; The residue was stored at Isolation of essential oil Dried and powderedfor herb 3 h material using (200dried Clevenger-type g over apparatus. each) anhydrous The sodium was essentialat sulfate distilled oils and, were after filtration, stored and consisted of five rows. Therethe was no plants fertilizer were application, watered and withdrought a seasons. The drip oregano irrigation plants were system harvestedapproximately four during the times the middle in of the months fromPlants June were to cut September. at a height ofshaded 10 area. cm above soil level and dried in a Labortechnik AG, Flawil, Switzerland; bath. Thewere extracts concentrated using were a rotary filtered evaporator (Rotavator, and B the solvent mixtures program for the FFAP column was from 60 30 Analysis of phenolic constituents The procedure for quantitationpreviously of the been phenolic described compounds by has Capanio was used asinjection volume of a each sample was carrier 5 components gas was based on at comparison of athose their mass of spectra flow with Wiley 14 andwas psi. Nist, set at (Split Tutore 70 eV. Libraries. 1 : The 20) ionization and energy obtained from the AegeanTurkey). Agricultural The Research seeds were Institute sown in (Izmir, a greenhouse,developed and in seedlings small were perforated plastic tubes, and then transplanted into an experimental field in rows spaced 50 in a randomizedExperimental Station block of Suleyman design Demirel Universitythe with in Mediterranean Isparta region three in of replications, Turkey (latitude at 37 the

206 207 1 33 − . at et al a 05). 05). dried herb, . . 0 0 essential oil) 1 − 1 ≤ ≤ Free radical − ) of essential oil d 214.70b P P 1 b − scavenging activity Origanum onites gmL µ = Months 50 herb) of 37.30b 32.40b 12.90c 1 − www.interscience.wiley.com/jsfa a also reported that the antioxidant power 34 . at different harvest times et al dried herb. The phenolic metabolite found at 1 − Phenolic content (g kg Reducing/antioxidant capacity (mg AAE g extracts at different harvest times. Twelve major phenolic Origanum onites nd, not detected. Differences between means indicated by the same letters are not Differences between means indicated by the same letters are not HPLC analysis was carried out to identify the phenolic content of and free radical scavenging activity (IC from Month Antioxidant capacity different harvest times a b Table 5. ComponentCaffeic acid June 62.30a July August Sept. Table 4. JuneJulyAugustSeptembera 31.02a 23.54d 24.61c 28.96b 116.74d 132.93a 123.75c 128.86b Vitexin 190.90c 558.60a nd RutinNaringinHesperidinRosmarinic acidEriodictiol 386.40dNaringenin nd nd 16.90b c cLuteolin 2948.70aGenistin 254.30a 1956.40b 38.20a 115.80bcApigenin 405.60a 62.60a 1282.40c Acecetin 125.50b 123.80b 219.60b 16.60b 84.00c 51.90b 19.10c nd c 94.60c 517.20b nd nd c c 321.90a 1898.20a nd c 223.10a 545.70b 35.80b 325.20a nd c 869.30b 189.60c 239.30b 41.80ab 739.60c 811.10a 47.70a 270.80d statistically significant (Duncan’s multiple range test, statistically significant (Duncan’s multiple range test, the next highest concentration was acecetin, at 1898.20 g kg dried oregano harvestedsignificance observed in in June.vitexin, the Other rutin, oregano luteolin, major extractsfound eriodictiol phenolics were at and of apigenin, levels84.00–325.20, naringenin, 0.00–254.30 of which and were 189.60–811.10, 94.60–223.10 g kg 0.00–558.60, 0.00–405.60, harvested in September, accordingand to Puertas-Mejia our results. Liolios O. onites metabolites were found:vitexin, rutin, rosmarinic luteolin, eriodictiol, acid,hesperidin and naringenin, caffeic acid acecetin, (Table genistin, 5). At naringin, all apigenin, harvestsamples, times of oregano rosmarinic acid wasJune the major harvest. phenolic, Rosmarinic except acid2948.70 for content g the kg was between 386.40 and of mixture of thymol andthymol carvacrol and carvacrol was due higher to than aagreement synergistic that with effect. of the Our findings pure results of are the in paper mentioned above. respectively. Genistin, naringin, hesperidin andgenerally caffeic acid found were general, in oregano lower extractof concentrations of these July phenolics in than harvest oregano the had extracts a of extracts. other higher harvest In content times. 13 1 . − et al 129.10d 05). at different . 2009 Society of Chemical Industry 0 Yaldiz Total amount c was highest at ≤ P 29–32 and 23.54–31.02 mg -cymene (3.16%) and -cymene (1.52–3.16%), 1 O. onites according to different p 5,10,13,15,28 herb) and extract (g kg p − 1 Origanum onites oil. Month − essential oil, respectively (Ta- atdifferentharvesttimeswere gmL a µ 1 − Nd 0.73 1.88 93 O. onites . -terpinene (0.00–1.05%). While car- also reported that methanol extract O. onites α -pinene was the highest in Septem- O.onites 27 α in different harvest times 74–132 a . : 205–209 species did not exhibit significant seasonal 90 116 -terpinene (2.63–6.15%), = thymol (94.63%) was the highest in the essential γ 2010; + 50 Essential oil composition (%) of The yield of essential oil (g kg 24 Origanum onites Juniperus -Terpinene 2.63 5.96 3.44 6.15 -Pinene nd -Terpinene 0.50 1.05 0.44 Nd nd, not detected. Differences between means indicated by the same letters are not -Cymene 1.52 3.16 2.28 2.07 The composition of the essential oil and amounts of its Free radical scavenging activities and reducing/antioxidant ca- Month Essential oil yield Extract yield a α Component June July August September Table 3. harvest times a June 25.00d herb) of Table 2. JulyAugustSeptember 30,00c 31.00b 32.00a 201.70a 147.90c 175.80b Carvacrol 87.15 88.65 87.17 83.97 α γ Thymolp 7.48 Nd 0.80 3.98 statistically significant (Duncan’s multiple range test, -terpinene (1.05%) had the highest value in July, thymol was -pinene (0.00–1.88%) and Influence of harvest time on essential oil composition of oregano www.soci.org ber. Carvacrol is aIt phenolic was monoterpene observed isomeric that with therecarvacrol were thymol. minor over changes the in months. thepublished content The literature, of showed examined that oil, carvacrolcharacteristic compared was constituent to the of main the and/or the highest in June, and α vacrol (88.65%), the main component, α yield of variations. components in leavesharvest time from areacterized given by in the Tablemain 3. presence components, The of in oregano(0.00–7.48%), six order, oil compounds carvacrol was and (83.97–88.65%), char- showed thymol as found as IC pacitiesofessentialoilfrom ascorbic acid equivalent (AAE) g of carvacrol oil harvested in June and the lowest (86.04%) in the essential oil ble 4). Essential oil of oregano samplesscavenging had activity the and highest reducing/antioxidant free capacity radical in June and the lowest in September. Previousand literature stated thymol that carvacrol had high antioxidant potential. J Sci Food Agric indicated that the essential oil content of the end of the flowering andstage. the Our beginning results of were the also seed agreement formation withby the Kokkini. findings reported extract yield didgrowth not and month. exhibit Adams regular changes related to plant , and JSci Food )and :19–32 ,ed.by Econ Bot Oregano: 23 : 205–209 Origanum, Acta Hortic Food Chem :1645–1651 Biochem Syst 90 82 () in Grasasy Aceites Origanum onites :361–383 (1955). 7 L. var bevanii. 2010; Am J Enol Vitic No. 14, IPGRI Rome ) extracts related to in Turkey, in Oregano: The Genera :691–700 (2002). Turkish J Bot , ed. by Charalambous G. 29 L. Origanum, Thymbra ¸ukurova. :Botany,chemistryand Promoting the Conservation ) essential oils. ¸er KHC and Hiltunen R, An Oregano J Sci Food Agric Origanum onites ¨ Uberegger E and Lanfranco SC, species growing wild in Lakes species, in nd Kirpik M, Seasonal and diurnal hirtum O. indercedens mong the flowering taxa of Turkey. J Sci Food Agric Oregano JPharmPharmacol Salvia officinalis and S. fruticosa ssp. :161–166 (2003). and Origanum syriacum ¨ umen G, Carvacrol-rich plants in Turkey. Origanum onites 39 L.) oil composition and variations during Thymbra , Vol. 3, New Delhi, India (1990). pp. 5–12. Origanum 11th International Congress of Essential Oils, :6–11 (1994). J Pharm Biomed Anal , ed. by Kintzios SE. CRC Press, Boca Raton, FL :37–41 (1995). 36th International Symposium on Essential Oils 3 and :527–545 (2002). 31 74 Spices,Herbs and EdibleFungi :1389–1396 (2004). ¸ O, Ozkan G and Karadogan T, Antibacterial activity 84 :169–172 (2004). Origanum onites Origanum vulgare species with commercial importance in Turkey. Thymus vulgaris antioxidant and antimicrobial activities of the essential 15 :287–295 (1993). Chem Nat Compd 21 :217–238 (1993). :254–258 (2005). :407–412 (1988). :203–209 (1999). :144–158 (1965). region in Turkey, in Budapest, Hungary 5–7 September (2005). Proceedings of the IPGRI InternationalPadulosi Workshop S, on Valenzano, Oregano Italy, 8–12and May. Use of Underutilized(1997). and pp. 122–132. Neglected Crops principles in medicinal plants. 56 improved on-line HPLC-DPPHradical method scavenging for the compoundsplants. screening in of water free extracts of Lamiaceae Antioxidant activity of sageoregano ( ( Thymus, Satureja plants in Greece,Fragrances in and Flavours cultivation, In Elsevier, Amsterdam (1994) pp. 439–456. Greece: distribution, volatile oil42 yield, and composition. oregano ( Control Chem Nat Compd their phenolic compound content. Ecol anatomy and ecology of (1999). variability of essential oilL. and grown its in components the ecological in conditions of C Satureja 333 Origanum and Lippia (2002). pp. 109–117. thyme ( the vegetative cycle. Food Agric and composition of essential oils from (2002). in vitro oil and various extracts of Newsletter Pure Appl Chem olive oil: influence64 of paste preparation techniques. phosphomolybdic–phosphotungstic16 acid. 6 Kitiki A, Status of cultivation and use of 7 Fluck H, Nat SC and Pharm M, The influence of climate on the active 8 Kokkini S, Vokou D and Karousou R, Essential oil yield9 of Lamiaceae Tucker AO and Maciarello MJ, 5 Baydar H, Karadogan T and Ozcelik H, Essential oils of 2 Baser KHC, Essential oils of Anatolian Lamiaceae: a3 profile. Baser KHC, Essential oils of4BaserKHC,TheTurkish Lamiaceae from Turkey: recent results. 1 Baser KHC, Aromatic biodiversity a 14 Kirimer N, Baser KHC and T 17 Pizzale L, Bortolomeazzi R, Vichi S, 16 Kosar M, Dorman HJD, Bachmayer O, Bas 10 Vokou D, Kokkini S and Bessiere JM, 11 Vokou D, Kokkini S and Bessiere JM, Geographic variation of Greek 15 Baydar H, Sagdic 12 Gonuz A and Ozgorucu B, An investigation13 on Yaldiz G, the Sekeroglu N, Ozguven morphology, M a 19 Hudaib M, Speroni E, Di Pietra AM and Cavrini V, GC/MS evaluation of 18 Tepe B, Daferera D, Sokmen M, Polissiou M and Sokmen AQ, The 20 Capanio F, Alloggio V and Gomes T, Phenolic compounds21 of virgin Singleton VL and Rossi JR, Colorimetry of total phenolics with ACKNOWLEDGEMENTS This study was supportedProjects Unit financially (Project: by SDUBAP the 0857-M-04)University, Isparta, Scientific of Turkey. Suleyman Research Demirel REFERENCES 40 35 ., at et al at differ- 05). . O. onites 2009 Society of Chemical Industry 0 www.soci.org G Ozkan, H Baydar, S Erbas extract. These c ≤ Free radical 1 extract), reduc- P − In addition, total 1 scavenging activity by Dorman − O. onites extract, 395.75 and 1 37 . 1 − − et al extract) and free radical gmL 1 µ − L. were found to be 22.21% )ofextractfrom 0 1 . 55.35% and 80–82% by Chun 108.31c 807.50a − capacity also found rosmarinic acid as a Antioxidant 38 335 ., 17 extract) and free radical scavenging also reported that total phenolic . gmL and Perry L. was 86 mg GAE g 1 = µ − 41 )ofextractfrom . et al 36 50 et al = 50 a 50 et al content Origanum vulgare , respectively (Table 6). While the highest total Total phenolic 1 Lu and Foo − and Pizzale 16 Total phenolic content (mg GAE g 16 Origanum vulgare ., . gmL and 149 mg and IC µ et al et al 39 extract, 108.31 and 180.41 mg AAE g 50 ., . Differences between means indicated by the same letters are not 1 Phenolic compounds such as rosmarinic acid is an efficient As a final conclusion of this study, all yields, chemical composi- Total phenolic content, antioxidant capacities and free radical Months different harvest times ing/antioxidant capacity (mg AAE g scavenging activity (IC a June 106.13d Table 6. statistically significant (Duncan’s multiple range test, JulyAugustSeptember 122.36c 138.92b 149.40a 151.87b 159.96b 180.41a 586.25b 494.21c 395.75d − phenolic content, reducing/antioxidant capacity andscavenging free activity radical were found inlowest in July June. As harvest, a all result, the ofscavenging highest activity them antioxidant and potential were free of radical oreganoplained in as the July highest harvest total were phenolic and ex- of rosmarinic acid oregano contents in the Julylowest harvest. antioxidant In and parallel free to radicalof this scavenging oregano activity hypothesis, were potential the of in total the June phenolicJune. harvest and and rosmarinic the acid lowest of contents oregano werenatural also antioxidant; in hence its application in the food industry. 807 phenolic content (mg GAE g activity values of www.interscience.wiley.com/jsfa CONCLUSIONS The yield and carvacrolacid content content, of total essential phenolics, oilsfree-radical reducing/antioxidant scavenging and capacity activities rosmarinic and of oregano extractshighest values showed at the the end of flowering–beginningin of July. fruit-set While stage the acecetin content of extract,capacity reducing/antioxidant and free radical scavenging activitiesmaximum of values essential in oil the had harvesthighest in of September. June, the yield of extract was tions, free radical scavenging activitiescapacities and of extracts reducing/antioxidant and essential oils of Turkish oreganoimportantly changed depending onson. vegetative periods of growing sea- respectively. Skerget The antioxidant potentialKosar of rosmarinic acid was reported by Kosar major phenolic and reportedOriganum a onites. similar phenolic composition for scavenging activities (IC et al content of findings are in agreement with our results. ent harvest timesg were between 106.13 and 149.40 mg GAE and 41–84% by Capecka

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