Quality characteristics and antioxidant properties of Turkish monovarietal olive oils regarding stages of olive ripening

Accepted Manuscript Quality Characteristics and Antioxidant Properties of Turkish Monovarietal Olive Oils Regarding Stages of Olive Ripening Oya Köseoğlu, Didar Sevim, Pınar Kadiroğlu PII: DOI: Reference:

S0308-8146(16)30920-7 http://dx.doi.org/10.1016/j.foodchem.2016.06.027 FOCH 19368

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Food Chemistry

Received Date: Revised Date: Accepted Date:

13 April 2016 8 June 2016 10 June 2016

Please cite this article as: Köseoğlu, O., Sevim, D., Kadiroğlu, P., Quality Characteristics and Antioxidant Properties of Turkish Monovarietal Olive Oils Regarding Stages of Olive Ripening, Food Chemistry (2016), doi: http:// dx.doi.org/10.1016/j.foodchem.2016.06.027

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Quality Characteristics and Antioxidant Properties of Turkish Monovarietal Olive Oils

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Regarding Stages of Olive Ripening

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(Abbreviated running title: Effect of Ripening on Quality Parameters of Turkish Olive Oils)

Oya Köseoğlu 1, Didar Sevim1, Pınar Kadiroğlu2*

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Department of Food Technologies, Bornova, Izmir, Turkey

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Ministry of Food, Agriculture and Livestock, Directorship of Olive Research Institute,

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Adana Science and Technology University, Department of Food Engineering, Seyhan, Adana, Turkey

* Corresponding Author: Tel.: +90 322 455 00 00 - 2120; fax: +90 322 455 00 09 Address: Adana Science and Technology University, Department of Food Engineering, 01180, Seyhan, Adana, Turkey E-mail address: [email protected]

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Abstract

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quality characteristics, chemical composition and antioxidant activity according to ripening

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stages of olives. Two different olive varieties (Memecik and Gemlik) were obtained at

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different stages of ripening based on skin color (green, purple and black). Quality properties

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of olive oils; free fatty acidity, peroxide value, K232 and K270, purity properties; fatty acid and

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triacylglycerol (TAG) composition and antioxidant compounds like total phenol, carotenoid

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and chlorophyll content and antioxidant activity (oxidative stability, ABTS radical scavenging

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activity) analyses were performed. Higher amount of oleic, linoleic and palmitic acids were

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observed in olive oils. Oleic acid amount of olive oils decreased, linoleic acid increased with

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ripening. The most abundant TAG of olive oils were ECN 48, OOO, SLO+POO, ECN 46 and

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LOO/PLO. Olive oils were clearly classified by principal component analysis based on fatty

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acid and TAG composition.

The aim of this study was to discriminate the extra virgin olive oils (EVOO) based on

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Keywords: Extra Virgin Olive oil, Ripening, Quality, Chemical composition, Antioxidant

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activity, Principal component analysis

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Introduction

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attention of consumers for health benefits of food products (Ortega 2006). Olive oils extracted

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from Memecik and Gemlik olive varieties are economically important olive oils in Turkey

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(İlyasoğlu & Ozcelik, 2011; Sevim, Köseoğlu, & Öztürk Güngör, 2013b). South Aegean

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Olive Oils produced from Memecik cultivar are certified by the Turkish Patent Institute as

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PDO (Protected Domination Origin) (TPI, 2004). The health benefits of olive oil can be

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related with its chemical composition which has effect on olive oil oxidative stability and

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quality (Bendini et al., 2007). Olive oil chemical composition consists of TAG (~99%) and

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free fatty acids, mono- and diacylglycerols, and lipids such as hydrocarbons, sterols, aliphatic

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alcohols, tocopherols, and pigments fatty acid composition of olive oil includes palmitic

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(C16:0), palmitoleic (C16:1), stearic (C18:0), oleic (C18:1), linoleic (C18:2), and linolenic

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(C18:3) acids (Boskou, Salta, Crysostomou, Mylona, Chiou, & Andrikopoulos, 2006).

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Phenolic compounds are the minor compounds in olive oils with high antioxidant activity

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providing nutritional and sensorial properties. Carotenoids exhibit antioxidant effect on virgin

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olive oils by quenching singlet oxygen inhibiting photosensitised oxidation (Beltran,

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Aguilera, Del Rio, Sanchez, & Martinez, 2005). The green colors of the olive fruits and olive

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oils are provided by chlorophylls and it is one of the quality parameters for olive oils

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(Giuliani, Cerretani, Cichelli, Giuliani, 2011). Chlorophylls show antioxidant activity in the

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dark while they act as pro-oxidant in the light (Gandul-Rojas & Minguez-Mosquera, 1996).

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Olive oil extraction using healthy fruits harvested at the right stage of ripening by using

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proper methods have influence on chemical characteristics of olive oils (Olias, Perez, Rios, &

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Sanz, 1993). Olive oil is resistant to oxidation because of its low polyunsaturated fatty acid

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composition and high contents of α-tocopherol and phenolic contents (Sevim, Tuncay, &

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Köseoğlu, 2013a).

Extra virgin olive oil (EVOO) consumption has increased due to the increased

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Several studies have been performed for determination of the effect of olive ripening

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stage on quality and chemical composition of olive oils obtained from Tunisian cultivars

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(Baccouri, Guerfel, Baccouri, Cerretani, Bendini, Lercker, Zarrouk, & Miled, 2008);

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Hojiblanca cultivars (Beltrán et al., 2005); Moroccan Picholine and autochthon cultivars

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(Boukachabine, Ajana, & El Antari, 2011); Spanish olive cultivars (Gómez-Rico, Fregapane,

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Salvador, 2008); Chilean cultivars (Romero, Saavedra, Tapia, Sepúlveda, & Aparicio, 2014)

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and Oblica and Leccino cultivars (Špika, Kraljić, Koprivnjak, Škevin, Žanetić, Katalinić,

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2015).

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According to our knowledge there is no detailed study on the influence of ripening

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stage on chemical composition and quality evaluation of Turkish olive varieties; Memecik

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and Gemlik. Therefore, the aim of this study is to determine the effect of olive ripening stage

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on chemical composition, oxidative stability and quality properties of olive oils obtained from

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Memecik and Gemlik cultivars in combination with PCA as a multivariate statistical method.

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2. Materials and Methods

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2.1. Olive Oil Samples

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Two different olive varieties; Memecik (M) and Gemlik (G) were harvested (15 kg) in

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the Olive Research Institute of Ministry of Food, Agriculture and Livestock in Izmir/Turkey

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in 2015 crop season at three stages of ripening according to skin pigmentation (green, purple,

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black). Olive oils were extracted by using Abencor laboratory oil mill (MC2 Ingenieria y

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Sistemas, Sevilla, Spain) equipped with fruit crushing, malaxation and centrifuge parts. The

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malaxation temperature was 30 ˚C and the duration of malaxation was 30 min. All oil samples

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were filtered and stored in the amber glass bottles and at +4˚C until they were analyzed. 100

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ml of each oil sample was used for the analyses.

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2.2. Maturity Index (MI)

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The olive maturity index was determined according to the method given by

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International Olive Council (IOC, 2011) based on the evaluation of the olive skin and pulp

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colors.

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2.3. Standard Chemical Parameters

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The free fatty acidity and the peroxide values were determined according to Turkish

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Food Codex (Anonymous, 2014) and UV spectrophotometric indices (K232 and K270

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measurements) were measured according to the methods given by International Olive Council

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(IOC, 2015). All parameters were determined duplicate for each sample.

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2.4. Fatty Acid Composition

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Fatty acid composition of olive oil samples was determined using gas chromatography

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system (HP 6890, Agilent Technologies, DE, USA) equipped with flame ionization detector

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(FID) described by International Olive Council (IOC, 2015). The capillary column (DB-23,

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30m *0.25 mm*film thickness: 0.250 µm, Agilent J&W GC Columns, DE, USA) was used

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for analyses. The temperature of the detector and injector was set to 250 oC. The oven

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temperature was programmed from 170 to 210 oC with an increment of 2 oC/min. The analysis

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was ended by maintaining the temperature to 210oC for 10 min. The injection volume was 1

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µl.

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2.5. Tocopherol Analysis

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Alpha tocopherol analysis was performed according to the methods given by

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Carpenter (1979) and IUPAC (1987). HPLC system (Agilent 1100) was operated for the

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analysis with µ-porasil column (250mm*4.6mm*5µm) (Waters, Ireland). The mobile phase

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consisted of hexane/2-propanol (99:1) and given to the system at a flow rate of 1 ml/min. The

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temperature of the column was set to 250 oC. The injection volume was 20 µl.

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2.6. Total Phenol Content

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Total phenol content of the samples was determined according to the method

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described by Gutfinger (1981) and Hrncirik & Fritsche (2004). 2.5 g of oil sample was

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dissolved in 5 ml of hexane and phenolic compounds were extracted using 5 ml

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methanol/water (60:40 v/v) by shaking the solution for 2 min. Hexane and methanol/water

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phases were separated from each other by centrifuging the solution at 3500 rpm for 10 min.

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0.2 ml of methanolic phase was put into flask and completed with deionized water to 5 ml,

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then Folin–Ciocalteau (0.5 ml) was added to the mixture. After 3 min, 1 ml of sodium

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carbonate (35 %, w/v) was added and diluted to 10 ml with pure water. After 2 hours of

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incubation, the absorbance of the solution was read at 725 nm with a spectrophotometer (UV-

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1700, Shimadzu, JAPAN). The total phenol content was expressed in mg equivalent of caffeic

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acid per kilogram of oil (mg CAE/kg).

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2.7. Antioxidant Activity Analysis

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ABTS•+ Radical Scavenging Activity (RSA) analysis of the olive oil samples was

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detected by the method given by Re, Pelegrini, Protegggente, Pannala, Yang, & Ce-Evans

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(1999). An aliquot of oil (0.5 g) was dissolved in 5 mL hexane. ABTS was dissolved in water

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to a 7 mM concentration. ABTS•+ was produced by reacting ABTS stock solution with 2.45

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mM potassium persulfate (final concentration) and mixture was left in darkness at room

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temperature for 12–16 h before use and diluted with ethanol to an absorbance of 0.70 (±0.020)

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at 734 nm (Re et al., 1999). 150 µL of sample (extract or standard) were mixed with ABTS•+

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(2,000 µL) and the mixture was kept at room temperature in darkness for 15 min. The

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absorbances of the ABTS•+ mixtures were measured at 734 nm with a spectrophotometer

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(Shimadzu Spectrophotometer UV-1700 PharmaSpec, Japan). The TE of the ABTS•+ RSA

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was calculated against the standard curve prepared with known concentrations of Trolox (R2

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= 0.9913). The data are expressed as µmol Trolox/100g oil of each sample.

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2.8. Oxidative Stability Analysis

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The oxidative stability analyses of the samples were conducted by using Rancimat 743

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(Metrohm Ltd., Herisau, Sweeden) according to the method described by Tura et al. (2007).

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2.9. Total Cholorophyll and Carotenoid Analyses

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7.5 g of olive oil sample was dissolved in cyclohexane and completed to 25 ml in a

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volumetric flask. Carotenoid and cholorophyll content of the sample was determined by

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measuring the solution at 670 nm and 470 nm with a spectrophotometer (UV-1700,

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Shimadzu, JAPAN), respectively (Minguez-Mosquera et al., 1991).

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2.10. Triacylglycerol Analysis

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The analysis of TAGs was performed according to the official liquid chromatographic

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method described in Regulation EEC/2568/91 of the European Union Commission

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(Anonymous, 1991). The chromatographic analysis was performed using an Instrument

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Agilent 1200 HPLC system consisted of a degasser, quaternary pump, manual six-way

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injection valve, differential refractometer detector, and Chemstation Software (3365 version)

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package for instrument control, data acquisition, and data analysis. The results were expressed

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in percentage of total TAG. The column was a Superspher® 100 RP-18 HPLC column

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(Merck, Germany) (250 x 4 mm i.d. x 4 µm). A loop of 100 µL capacity was used in which

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0.5 µL of sample was injected. Acetone (63.6 %) / acetonitrile (36.4 %) were mobile phases

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with a flow rate linear gradient (1.200 mL min-1) under nebulizer gas pressure 2.00 bar for 45

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min.

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2.11. Statistical Analysis

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Analysis of variance (ANOVA) was applied to indicate the differences among the

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samples using the Fisher’s least significant difference test at p<0.05 significance level. The

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multivariate data analysis was performed with PCA to analyse the results of fatty acid and

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triacylglycerol composition of the samples. The data matrix consisted of observations (olive

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oil samples) and variables (fatty acid and triacylglycerol concentrations). PCA score and

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loading plots were constructed for visual interpretation of the results. All results were

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analysed using Minitab® 16 programme (Minitab Inc., State College, USA).

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3. Results and Discussion

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3.1. Maturity Index (MI)

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MI values of the samples were determined for each variety. Maturity index of

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Memecik olives were classified into three groups; 2.4 (green); 3 (purple); 6.2 (black).

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Maturity index values of Gemlik olives were found as 2.1 (green); 2.5 (purple); 4.1 (black).

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3.2. Standard Chemical Parameters

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IOC (IOC, 2015). All olive oil samples were categorized as “extra virgin olive oil” according

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to the free fatty acidity values ranging from 0.14 to 0.46 (% oleic acid). As can be seen in

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Table 1, ANOVA analysis showed that there were significant differences between the samples

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depending on free fatty acidity values (p<0.05). In both of the olive oil samples, free fatty

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acidity values increased slightly during ripening. This result was in accordance with other

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studies (Baccouri et al., 2008; Salvador, Aranda, & Fregapane, 2001).

Free fatty acidities of the samples were within the limit of the values established by

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The peroxide value and UV spectrophotometric characteristics were the important

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parameters describing the oxidative status of the oil samples. The peroxide value of extra

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virgin olive oil was given as ≤20 meq O2 kg−1 by IOC. K232 and K270 values were

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demonstrated as ≤2.5 and ≤0.20 respectively for extra virgin olive oil categorization. All the

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samples exhibited the values within the range of the limits for extra virgin olive oil.

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3.3. Major Compounds of Olive Oils

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3.3.1. Fatty acid composition

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palmitoleic, heptadecanoic, stearic, oleic, linoleic, linolenic, arachidic, gadoleic, behenic and

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lignoceric). Fatty acid composition of the olive oil samples was shown in Table 2. The major

Fatty acid composition of olive oils was investigated with fatty acids (palmitic,

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fatty acids found in Memecik and Gemlik olive oils were oleic, linoleic, palmitic and stearic

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acids. The major fatty acid was oleic acid ranging from 68.68 % to 73.95 % for both varieties

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of olive oils. This oleic acid limit was 71.04% for Gemlik oil which was slightly higher than

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68.68% found in our study for Gemlik oil obtained from black olives (Matthäus & Ozcan

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2011). The oleic acid content of the samples was within the 55.00-83.00% limits established

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by IOC (2003). The oleic acid of olive oils decreased as the skin color of the olives changed

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from green to black. The linoleic acid amount (range between 5.01-11.81 %) was between the

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limits established as 2.5-21.0% by IOOC. The concentration of linoleic acid increased from

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8.01% to 11.81% for Memecik olive oils and from 5.01% to 9.87% for Gemlik olive oils

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during ripening. The linolenic acids levels (range between 0.69-0.79%) of the olive oil

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samples were below the limit established by IOC (1.0 %). There were significant differences

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between the olive oil samples concerning palmitoleic, linolenic and gadoleic fatty acids

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(p<0.05).

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The ratios of MUFA/PUFA and oleic acid/linoleic acid were higher in Gemlik olive

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oil samples than Memecik oil samples (Fig. 1). These ratios decreased during the olive

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ripening process. This can be explained by the activity of oleate desaturase enzyme that

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transforms oleic acid to linoleic acid and catalyse the formation of double bonds (Gutiérrez,

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Jiménez, Ruiz, & Albi, 1999).

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PCA was performed to discriminate the olive oil samples based on fatty acid

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composition of olive oils according to harvest time and variety. PCA was constructed with 2

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components accounting for 87.6 % of total variance. The results were graphically represented

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by PCA score and loading plots. As it can be seen from Fig. 2a, Memecik and Gemlik olive

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oils were clearly discriminated according to variety and stage of ripening. Loading plot (Fig.

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2b) of the variables (fatty acids) showed that gadoleic (C20:1) and linoleic (C18:2) acids were

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responsible for discrimination of Memecik olive oils.

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3.3.2. Triacylglycerol (TAG) composition

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OOO (triolein), SLO+POO, LOO+PLnP, SOO, POP and PLO+SLL. These accounted for

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90.0 % of the total peak areas in the chromatogram. The OOO varies between 31.45-36.75 %

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for Memecik olive oils while it ranged between 31.55-39.37% for Gemlik olive oils. The

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OOO level of Memecik olive oil has been determined lower than the results of Gokcebag et

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al. (2013). The presence of OOO at high levels indicates authenticity of olive oils (Gokcebag

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et al., 2013). In addition, all olive oil samples had low amount of LLL (trilinoein). The results

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of five equivalent carbon number analysis (ECN 42, ECN 44, ECN 46, ECN 48 and ECN 50)

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revealed that ECN 48 fraction was the determined between 60.42-94.96 % as the highest

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values in the both varieties of olive oil samples at all stages of ripening. This value was

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followed by ECN 46 (between 13.93-27.86%) values. These TAG values and other

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parameters (ECN 42-ECN 50) were comparable with other studies (Baccouri et al., 2008;

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Boukachabine et al., 2011; Gokcebag et al., 2013).

TAG composition of olive oils was listed in Table 3. The main triacylglycerols were

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TAG composition of olive oils was used to discriminate olive oil samples obtained

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from different ripening stages of olives. PCA was performed with 3 principal components

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which account for 92.0 % of the variability in the data (Fig. 3a). According to loading plot

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(Fig. 3b) of TAG data, Memecik cultivar of olive oil was characterized by OOO/POO (O5) at

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green and black stages of ripening. LOO+PLnP, LLL/ECN 42, OLL, PLO/OOO, ECN 46,

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PLO+SLL were responsible for discrimination of M olive oils obtained from oils at black

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ripening stage. POP played role in characterization of Gemlik (purple) oils while ECN 48 /

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ECN 46 and SOO were effective for characterizing Gemlik (green) oils. Also, Gemlik (black)

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olive oil was characterized by POLn and PoOP.

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3.4. Minor Compounds of Olive Oils

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In olive oil, vitamin E is represented by tocopherol. Tocopherols have inhibitory effect

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on LDL oxidation and they have several nutritional benefits (Beltran et al., 2005).

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Tocopherols play a key role in preserving oil from rancidity during storage.

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tocopherol content of the olive oil samples ranged from 296.40 to 377.64 mg/kg. In our

279

research, α-tocopherol content decreased during fruit ripenig for Gemlik olive oil, but in the

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Memecik olive oil it increased with ripening. Gutiérrez, Jiménez, Ruiz, & Albi (1999)

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reported that the tocopherol content of olive oil decreased during fruit ripening. Sevim et al.

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(2013a) and Salvador, Aranda, Gómez-Alonso, & Fregapane (2003) reported that α-

283

tocopherol content of olive oil does not show a clear trend in relation to the maturity stage of

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olive fruit. Our research was similar with other researchers.

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Chlorophylls and carotenoids have antioxidant effect in virgin olive oils (Beltran et al.,

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2005). Total carotenoid and chlorophyll measurements of the olive oil samples indicated the

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same trend with ABTS•+ assay and oxidative stability of olive oils as the total carotenoid and

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total chlorophyll content decreased when ripening progressed. Similar results were reported

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by Salvador et al. (2001) and Gutiérrez et al. (1999).

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3.5. Total Phenol Content

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Total phenol content is an important parameter for olive oils influencing antioxidant

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potential and sensory quality of olive oils. Phenolic composition of olive oils is affected by

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cultivar, fruit ripening and some technological and agronomic conditions (Servili &

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Montedoro, 2002). Total phenol content of Memecik olive oil samples were significantly

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higher than Gemlik olive oil samples at all stages of ripening. Total phenol contents of olive

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oils obtained from the olives at purple ripening stage were significantly higher than other

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stages in both of the olive cultivars. There were significant differences between the olive oil

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samples according to total phenol contents (p<0.05). The difference between the phenol

299

contents of the olive oils was related to difference between the polysaccharides of the cell

11

300

wall affecting the release of phenolic compounds during crushing of fruits and malaxation

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stages (Tovar, Motilva, & Romero, 2001). The effect of fruit ripening and cultivar on the

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amount of phenolic compounds such as oleropein and demethyloleuropein was reported

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previously (Amiot, Fleuriet, & Macheix, 1986).

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3.6. Oxidative Stability

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The oxidative stability of olive oils is influenced especially by the fatty acid

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composition and the presence of phenolic compounds. Oxidative stability of olive oils was

307

measured using Rancimat method and given in Table 1. The values of the olive oils extracted

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from green stage olives were significantly higher than other olive oil samples and decreased

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as the fruits ripened. The oxidative stability of Memecik olive oil was reported as 12.7 h by

310

Kıralan & Bayrak (2012). This value was between purple and black ripening stage of olive

311

oils used in this study related with the difference between the maturity levels of olives. The

312

oxidative stability of both varieties of olive oils was lower than the oxidative stability of olive

313

oils obtained from “Cornicabra” varieties (Salvador et al., 2001).

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3.7. Antioxidant Activity of Olive Oils

315

The antioxidant properties of olive oils depend on several factors such as the cultivar,

316

fruit ripening stage, agloclimatic conditions and olive growing methods (Beltran et al., 2005).

317

The ability of antioxidant molecules or extracts to scavenge ABTS•+ radical was measured in

318

this study. The antioxidant activity of our olive oils decreased during ripening. However, the

319

antioxidant capacity of Memecik olive oils was significantly higher than Gemlik olive oils.

320

Similar results were reported by Kelebek, Kesen, & Selli (2015) that the antioxidant

321

capacities of Memecik and Gemlik olive oils obtained with ABTS RSA assay were 0.83 and

322

1.31 (µmol Trolox/100g oil), respectively. The oxidative stability of olive oils decreased with

323

antioxidant activity values of olive oils. It is reported that, ABTS•+ radical scavenging activity

324

was positively affected by total phenol (Pellegrini, Visioli, Buratti, & Brighenti, 2001;

12

325

Galvano et al., 2007) and α-tocopherol contents (Pellegrini et al., 2001; Gorinstein et al.,

326

2003) of olive oils. Our results showed that ABTS•+ radical scavenging activity is more

327

affected by α-tocopherol compared than by total phenol content.

328

between the antioxidant capacity and total phenol content of olive oils was evaluated, the

329

results showed strong correlation between ABTS•+ RSA and total phenolic compounds

330

(r=0.89).

331

4. Conclusions

When the correlation

332

This study was performed to determine the effect of ripening stage on chemical

333

parameters, major and minor compounds, total phenolic content, oxidative stability and

334

antioxidant activity of two different varieties (Memecik and Gemlik) of olive oils. According

335

to the results, free fatty acidity, α-tocopherol, total phenol contents of olive oils increased with

336

ripening until purple stage of the olives then decreased as ripening progressed. The ratios of

337

MUFA/PUFA and oleic acid/linoleic acid decreased during ripening. K232, K270, oxidative

338

stability, antioxidant activity, total cholorophyll and carotenoid contents of olive oils

339

decreased with ripening. PCA analyses of olive oils indicated that different TAG and fatty

340

acid components were responsible for characterization and classification of olive oils obtained

341

from olives at different ripening stages. This study revealed that ripening stage is an important

342

parameter for characterization and discrimination of Memecik and Gemlik olive oils.

343 344 345 346 347 348 349

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512 513 514

Figure Captions Fig. 1. MUFA/PUFA and Oleic acid/Linoleic acid ratios of Memecik and Gemlik olive oils at

515

3 ripening stages (MG: Memecik (green); MP: Memecik (purple); MB: Memecik

516

(black); GG: Gemlik (green); GP: Gemlik (purple); GB: Gemlik (black).

517 518 519 520

Fig. 2. a) Scores and b) loading plots with PCA according to fatty acid profiles of Memecik and Gemlik olive oils Fig. 3. a) Scores and b) loading plots with PCA according to TAG composition of Memecik and Gemlik olive oils

521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 20

554

Table Captions

555

Table 1: Quality properties of olive oil samples

556

Table 2: Fatty acid composition (%) of olive oil samples

557

Table 3: Triacylglycerol (%) composition of olive oil samples

558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594

21

595 596 597 598 599 600 601 602 603 604 605 606 607 608

Fig. 1.

22

609 610 611 612 613 614 615 616 617 618 619 620

Fig. 2.

23

621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637

Fig. 3.

24

Table 1: Quality properties of olive oil samples Alpha Samples

Tocopherol

K232

K270

(mg/kg)

Oxidative

ABTS•+ RSA

stability (h)

(µmol TE/100g oil)

Total

Total

Total

Free Fatty

Peroxide

Phenol

chlorophyll

carotenoid

Acidity

Values

(mgCAE/kg)

(mg/kg)

(mg/kg)

(% oleic acid)

(meqO2/kg)

MG

296.40±0.33e

1.66±0.00a

0.13a

16.82±0.04a

132.87±1.00a

372.70±10.76b

8.83±0.02a

4.03±0.04a

0.34b

4.30±0.03c

MP

305.48±0.79d

1.65±0.01a

0.13a

13.86±2.22c

126.31±0.25b

407.13±14.15a

3.12±0.03c

1.90±0.01c

0.46a

3.74±0.01d

MB

313.64±0.21c

1.54±0.01b

0.11b

11.14±0.23d

118.33±0.50c

296.24±18.12c

2.58±0.05d

1.46±0.04d

0.45a

4.55±0.01b

GG

377.64±4.22a

1.44±0.03c

0.08d

16.59±2.02a

94.93±3.01d

194.96±9.62e

3.67±0.02b

2.05±0.04b

0.14d

4.74±0.00a

GP

335.44±2.28b

1.40±0.00d

0.08c

15.82±0.04b

79.50±0.75e

245.40±9.62d

1.13±0.02e

0.93±0.01e

0.25c

2.60±0.00e

GB

299.31±0.71e

1.44±0.00c

0.08c

9.87±3.64e

76.49±0.50e

150.92±5.10f

0.59±0.02f

0.54±0.05f

0.24c

2.46±0.02f

a-f

Different letters in the same column concerning all samples significantly different values (p<0.05)

25

Table 2: Fatty acid composition (%) of olive oil samples Olive oils a MG MP MB GG GP GB

C16:0 14,93 14,69 14,56 14,70 15,42 15,49

C16:1* 0,85

e

de

0,95 1,07

cd

bc

1,12

b

1,25

1,60

a

C17:0 0,04 0,04 0,03 0,16 0,13 0,12

C17:1 0,07 0,07 0,06 0,27 0,25 0,24

C18:0 2,12 2,00 1,95 3,09 2,81 2,43

C18:1 72,37 71,23 68,92 73,95 72,03 68,68

a

C18:2 8,01 9,42 11,81 5,01 6,46 9,87

C18:3* 0,69

e

de

0,70 0,74

cd

bc

0,75

b

0,76 0,79

a

C20:0 0,40 0,38 0,37 0,48 0,44 0,38

C20:1*

C22:0

C24:0

0,32

a

0,12

0,08

0,33

a

0,11

0,08

0,31

a

0,12

0,07

0,28

a

0,13

0,10

b

0,12

0,09

b

0,10

0,07

0,27 0,26

First letter indicates the olive variety Memecik (M) and Gemlik (G) and second letter indicates the ripening stage of olives G: Green, P: Purple, B: Black *a-e Different letters in the same column concerning all samples significantly different values (p<0.05)

26

Table 3: Triacylglycerol (%) composition of olive oil samples Samples LLL

Codes

MG

MP

MB

GG

GP

GB

0.05

0.09

0.18

0.00

0.00

0.14

0.29 0.09 2.06 1.38

0.38 0.11 3.08 1.44

0.24 0.06 0.63 1.41

0.32 0.08 1.03 1.53

0.43 0.11 2.35 1.78

0.54 0.64 14.88 0.55

0.90 0.70 16.70 0.60

0.26 0.64 7.87 1.09

0.40 0.71 9.82 1.40

0.76 0.76 12.92 1.64

7.67 0.46 0.85 36.58

8.89 0.66 1.02 31.45

4.09 0.37 0.52 39.37

5.66 0.75 0.94 36.66

7.78 1.01 1.26 31.55

24.41 3.66 0.50 3.46

24.47 4.09 0.43 3.11

29.81 4.41 0.60 5.54

28.51 4.28 0.53 4.79

26.62 4.53 0.42 3.71

1.06 0.47 4.62 24.40

1.11 0.67 6.10 27.86

1.82 0.30 2.94 13.93

1.57 0.40 3.66 18.56

1.38 0.68 5.65 24.60

65.14 4.52 0.21 0.19

60.42 4.22 0.28 0.27

74.19 7.36 0.10 0.01

69.96 6.36 0.15 0.00

63.12 5.09 0.25 0.20

0.26 2.67 27.56 1.50

0.29 2.17 18.67 1.29

0.41 5.33 30.30 1.32

0.39 3.77 24.90 1.29

0.32 2.57 17.11 1.19

ECN 42

L1 0.23 L2 0.07 P1 1.42 O1 1.26 O2 0.40 P2 0.65 P3 12.38 L3 0.64 P4 6.58 P5 0.57 P6 0.77 P7 36.75 O4 27.46 S1 4.55 P8 0.49 P9 3.63 S2 1.23 P10 0.35 E1 3.73 E2 20.93 E3 69.24 E4 4.86 E5 0.18 P11 0.14 L4 0.28 P12 3.31 E6 31.03 L5 1.34 O5 LLL+LOLn+POLL+PLLn

ECN 44 ECN 46 ECN 48 ECN 50

OLL+OLnO+PLL+POLn LOO+PLnP+PoOO+PLO+SLL+PoOP+PLP OOO+SLO+POO+POP+PPP SOO+POS

LOLn +POLL PLLn OLL OLnO PLL POLn LOO +PLnP PoOO PLO + SLL PoOP PLP OOO SLO + POO POP PPP SOO POS ECN 42 ECN 44 ECN 46 ECN 48 ECN 50 PLO/OOO LLL/ECN42 PLL/OLL ECN48/ECN46 LOO/PLO OOO/POO

27

Highlights 1- Effect of ripening stage on Turkish monovarietal olive oils; Memecik and Gemlik. 2- Quality properties of olive oils related to olive cultivar and ripening stage. 3- Relation between chemical composition and ripening stages was determined. 4- Chemometric analyses of olive oils based on fatty acid and TAG composition.

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