Ali Bayrak

Composition of essential oils from turkish Salvia species

The chemical composition of the essential oils from five Salvia species from Turkey was determined by GC. The species were S. candidissima, S. cryptantha, S. fruticosa, S. officinalis and S. tomentosa. 24, 22, 20, 19, and 22 components were identified, respectively, the major ones being β-pinene (candidissima), borneol (cryptantha), 1,8-cineole (fruticosa), camphor (officinalis) and β-pinene (tomentosa). α-Pinene in candidissima, camphor in cryptantha, α-thujone in officinalis and 1,8-cineole in tomentosa were the other important components.

Comparative volatile oil composition of various parts from Turkish bitter fennel (Foeniculum vulgare var. vulgare)

Abstract The volatile oil composition of various parts of bitter fennel (Foeniculum vulgare var. vulgare) growing as wild Turkish plants was investigated by gas-liquid chromatography. The major component of all oil samples was trans-anethole (29·70, 37·07, 54·22, 61·08, 64·71% in leaf, stem, flowering umbel, flower, fruit, respectively). The other main components were α-pinene in leaf, stem, flowering umbel, flower: α-phellandrene in leaf, stem, flowering umbel; fenchone in fruit oil. The volatile oils of flowering umbel, flower and fruit contained high amounts of oxygenated compounds, in gradually increasing percentages.

Essential oil composition and antiradical activity of the oil of Iraq plants

This study examined the antiradical activity and chemical composition of essential oils of some plants grown in Mosul, Iraq. The essential oils of myrtle and parsley seed contained α-pinene (36.08% and 22.89%, respectively) as main constituents. Trans-Anethole was the major compound found in fennel and aniseed oils (66.98% and 93.51%, respectively). The dominant constituent of celery seed oil was limonene (76.63%). Diallyl disulphide was identified as the major component in garlic oil (36.51%). Antiradical activity was higher in garlic oil (76.63%) and lower in myrtle oil (39.23%). The results may suggest that some essential oils from Iraq possess compounds with antiradical activity, and these oils can be used as natural antioxidants in food applications.

Oxidative and Antiradical Stabilities of Two Important Virgin Olive Oils from Ayvalik and Memecik Olive Cultivars in Turkey

Memecik and Ayvalik olive cultivars were harvested from Mugla province of Turkey and processed into oil using a three phase decanter. The oils of these cultivars were subjected to free fatty acid, peroxide value, ultra violet absorption, and fatty acid composition analysis. The results showed that all obtained values were very similar and within the limits of the International Olive Oil Council regulation for virgin olive oil. The oxidative stability in samples was assessed in terms of primary and secondary oxidation products using peroxide values and induction times, respectively. Total phenol and o-diphenol contents were determined by spectrophotometric assays. The antiradical capacity of phenolic fraction was determined by 1,1-diphenyl-2picrylhydrazyl method. These analyses showed that oxidative resistance, antiradical capacity, and the content of phenols and o-diphenols were higher for Memecik oil than Ayvalik oil.

Effect of different drying methods on the essential oil yield, composition and antioxidant activity of Origanum vulgare L. and Origanum onites L.

Origanum onites and Origanum vulgare are important medicinal plants because of their flavoring, therapeutic, and preservative properties. Drying methods are important for obtaining high quality essential oil from spices. In this study, the effects of different drying processes on the essential oil yield, composition, and antiradical activity were evaluated. Plants were dried under sun light, in a ventilated shady place and in laboratory-type oven, and the oils were extracted with Clevenger type apparatus. Carvacrol and thymol were the major compounds in the essential oils of O. vulgare and O. onites, respectively. The highest oil yield and the highest antioxidant activity values were obtained from shade dried Origanum species followed by oven dried plants. The lowest essential oil yield and the lowest antioxidant activity for O. vulgare were found in fresh plants. The lowest essential oil yield, and the lowest antioxidant activity for O. onites belonged to sun dried plants. It could be concluded that essential oil yield, oil composition and antioxidant activity of both plants were greatly affected by the drying method.

Individual and Combined Use of Rosemary and Origanum in Soybean Oil as Natural Antioxidants

Dried rosemary and origanum were added to soybean oil, individually and in combination, to determine their effect on the oxidation stability of soybean oil. Samples were stored at two different temperatures (60°C and room temperature) and oxidation was determined by peroxide value and conjugated diene value. The treated soybean oil samples showed evidence of antioxidant activity at 60°C and at room temperature. Furthermore, it was observed that the herbs stored under room temperature had a higher activity compared to those stored at 60°C.

Phenolic Compounds of Olive Oils from Aegean Region

Bu calismada, Turkiye’de baslica zeytin yetistiriciligi yapan Ege bolgesinin bazi illerinden (Mugla, Aydin, Izmir ve Manisa) 2 hasat donemi (2007-2008 ve 2008-2009) suresince yerli zeytin cesitlerinin (Gemlik, Memecik, Ayvalik, Uslu ve Domat) yagi incelenmistir. Bu yaglarin toplam fenolik madde ve fenolik bilesimi belirlenmistir. Yaglarin toplam fenolik madde icerigi, 2007-2008 hasat donemi orneklerinde 23,69-153,64 mg kafeik asit/kg, 2008-2009 hasat donemi orneklerinde 16,18-136,22 mg kafeik asit/kg araliginda belirlenmistir. Tum zeytinyagi orneklerinde tespit edilen fenolik maddeler; tirozol, oleuropein, 4-hidroksifenil asetik asit, luteolin, vanilik asit, hidroksitirozol, rutin, sinnamik asit, verbaskozit, hidroksi fenilkarboksilik asit, sirinjik asit, 3,4-dihidroksibenzoik asit, kafeik asit, ferulik asit, p-kumarik asit, taksifolin ve apigenindir. Tirozol ve oleuropeinin, 2007-2008 hasat doneminde 1,80-13,39 mg/kg, 1,26-19,50 mg/kg ve 2008-2009 hasat doneminde ise 1,76-11,66 mg/kg, 0,20-13,12 mg/kg araliginda en fazla miktarda degisen bilesenler oldugu saptanmistir.

Volatiles in an endemic Allium specie: Allium tuncelianum by headspace solid phase microextraction

The volatile components of an endemic garlic, Allium tuncelianum were extracted using solid-phase microextraction and analyzed by Gas chromatography and Mass Spectrometry (GC-MS). A total of 14 volatile components were identified in red and green garlic. Most of the identified compounds were sulphur compounds. The main sulphur compound was diallyl disulfide and its content in red and green garlic was 72.52 % and 67.33 %, respectively. In analysis of volatile compounds, importance of differences in content of red and green garlic were found in methyl allyl disulfide content.