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Öğe Bitkisel yağların stabilizasyonunda doğal antioksidanların rolü(2005) Kıralan, Mustafa; Bayrak, AliOksidasyon, yağların bozulmasında en önemli reaksiyonlardan biridir. Oksidasyonu önlemek için en yaygın ve en etkili yöntem antioksidan kullanımıdır. Sentetik antioksidanların sağlık üzerine birçok olumsuz etki göstermesi doğal antiok-sidanlara olan ilgiyi artırmaktadır. Doğal antioksidanlarca zengin kaynaklar baharat, tıbbi bitki, çay, yağ, tohum, protein, sebze, tahıl ve meyvelerdir. Bu çalışmada, bitkisel yağların stabilizasyonunda kullanılan çeşitli doğal antioksidanlar ve bunların antioksidatif etkileri irdelenmiştir.Öğe Çemen otu (Trigonella foenum-graecum L.) tohumunun yağ asitleri ve sterol bileşimi(2017) Kıralan, Mustafa; Yorulmaz, Aslı; Çalıkoğlu, Eda; Bayrak, AliÜç farklı ilden alınan çemen otu tohumlarının yağ verimi, yağ asitleri ve sterol bileşimi incelenmiştir. Çemen otu tohumlarından çözücü ekstraksiyonu ile yağ elde edilmiş ve oranı %7.01-8.82 aralığında belirlenmiştir. Gaz kromatografi sonuçlarına göre çemen otu tohum yağları doymamış yağ asitleri açısından zengin bulunmuştur. Özellikle linoleik asit doymamış yağ asitlerinden en önemlisi olup %45.10-46.19 aralığında tespit edilmiştir. Yağ örneklerinin toplam sterol içeriği 8 681.54 - 9 591.70 ppm arasında değişen değerler almıştır. Temel sterol βsitosterol olup, örneklerde toplam steroller içinde %59.94-68.24 arasında değişen oranlarda bulunmuştur.Öğe Comparison of antiradical activities and compositions of essential oils of two Origanum spp. from Turkey(2011) Coşge, Belgin; Kıralan, Mustafa; İpek, Arif; Bayrak, Ali; Gürbüz, BülentHydro-distilled essential oils from the aerial parts of Origanum vulgare L. subsp. hirtum (Link) Letsw. (OVH) and Origanum onites L. (OO) were analyzed by GC/MS. Twelve compounds comprising 98.89% of the (OVH) essential oil were characterized, and the main components were thymol (58.35%) and ?-terpinene (23.22%). Twenty compounds representing 94.58% of the (OO) essential oil were identified, among which carvacrol (73.90%) and ?-terpinene (5.96%) were the major ones. Antiradical activities of essential oils investigated were tested using the DPPH radical-scavenging method. DPPH radical scavenging activities of two Origanum species essential oils were very high, and this was obviously related to their chemical compositions which were markedly rich in phenolic components such as thymol and carvacrol.Öğe Comparison of oxidation stability of virgin olive oils from different locations of Turkey(Akademiai Kiado Rt, 2014) Karakuş, M.; Bayrak, Ali; Çalıkoğlu, Eda; Kiralan, MustafaTen kinds of virgin olive oil of two major cultivars (Ayvalik and Memecik) produced in several areas of Turkey (Bayindir, Edremit, Ortaklar, Burhaniye, Ezine, Tire, Havran, Ayvalik, Altinoluk, and Kucukkuyu) were analysed. The quality characteristics, fatty acid composition, total phenol, and o-diphenol content of the samples were determined. Oxidative stability and free radical scavenging activity were determined using Rancimat test, Schaal oven test, and DPPH method. It was found that while Memecik oil from Ortaklar demonstrated the strongest oxidative stability, Ayvalik oil from Ezine had the lowest oxidative stability among the samples. Fatty acid composition and especially oleic acid/linoleic acid ratio was previously defined as a parameter that can help distinguish cultivars from one another; however, this study proved that total phenol, especially o-diphenol content of the oil, has the strongest effect on oxidative stability compared to other factors including fatty acid composition.Öğe Determination of aroma profiles of olive oils from Turkish olive cultivars(Wiley, 2013) Bayrak, Ali; Kıralan, Mustafa; Kara, Hasan HüseyinThis study analyzed volatile aromatic compounds present in the oils of Turkish olive cultivars. The cultivars Gemlik, AyvalA +/- k, Memecik, Domat, Uslu, HalhalA +/-, Kilis yaglA +/- k, Nizip yaglA +/- k, HaAYebi and Karamani were harvested from important Turkish olive-growing locations, such as BalA +/- kesir, Bursa, Manisa, AydA +/- n, Mugla, A degrees zmir, Kilis, Mersin, Hatay and Gaziantep during the 2007-2008 and 2008-2009 growing seasons. Olive samples were collected in two harvest years, at almost the same maturity stage, and processed under the same conditions. Headspace solid-phase microextraction (HS-SPME) was used to analyze volatile aroma compounds in the olive oil samples. Forty-seven compounds were characterized and quantified using gas chromatography-mass spectrometry/flame ionization detector (GC-MS/FID). The most abundant identified compounds were trans-2-hexenal, hexanal and 3-methyl-1-butanol. The trans-2-hexenal, hexanal and 3-methyl-1-butanol contents of oil samples varied between 0.86-67.15, 3.93-61.82 and 0.48-84.74 %, respectively.Öğe Effect of cultivation area and climatic conditions on volatiles of virgin olive oil(Wiley-Blackwell, 2012) Kiralan, Mustafa; Özkan, Gülcan; Köylüoğlu, Fatma; Uğurlu, Hatice Aşık; Bayrak, AliTo elucidate the influence of the cultivation area and climatic conditions on volatiles of virgin olive oil from Gemlik cultivar, an investigation was carried out. Five Turkish geographical zones (Balikesir, Aydin, Manisa, Antalya and Hatay) were chosen. From these areas, fruits were collected at the same maturity stage and processed using a small experimental olive oil mill, applying identical processing conditions for all olive samples. Headspace solid-phase microextraction (HS-SPME) technique coupled to GC/MS was used for volatile analysis. Twenty-seven compounds were identified and characterised, representing 96.4098.74% of the total GC area. The major volatile representing about 50% was the (E)-2-hexenal. This compound was found in higher concentrations on olive oils from Antalya than from Hatay area. Hexanal was the second most abundant volatile compound and varied between 13.89 and 28.96%. Comparing the olive growing areas Hatay and Antalya, the hexanal concentration was about 29 and 14%, respectively. Generally, a significant difference in the composition of volatile compounds between the oils from the same olive cultivar and from different geographic regions was recorded. The results suggest that climatic factors, latitude and longitude affect the formation of volatiles.Öğe Effect of different drying methods on the essential oil yield, composition and antioxidant activity of Origanum vulgare L. and Origanum onites L.(Springer, 2018) Özdemir, Necla; Özgen, Yasin; Kıralan, Mustafa; Bayrak, Ali; Arslan, NeşetOriganum 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.Öğe The effect of different manures and synthetic fertilizer on biochemical and antimicrobial properties of mentha piperita?L(Wiley, 2014) Özbucak, Tuğba Bayrak; Ertürk, Ömer; Yıldız, Oktay; Bayrak, Ali; Kara, Meryem; Sahin, Huseyin; Kiralan, MustafaThe study was designed to examine the effects of different manures (fish, pigeon and cow) and synthetic fertilizer (nitrogen) on some biochemical activities of Mentha piperita L. (mint, peppermint). Seventeen different phenolic constituents and 19 essential oils were determined in M. piperita samples. While caffeic, gallic, ferulic, protocatechuic, syringic, o-coumaric acids and rutin were detected as common phenolics; carvone, limonene and 1.8-cineol were identified as major essential oil components in all mints. Total phenolic compounds, ferric reducing antioxidant power and cupric (III) reducing capacity (CUPRAC) tests were used to evaluate antioxidant capacities of the mints. The highest total phenolic compound (4.8 mg gallic acid equivalents/100 g) and antioxidant capacity (971 mM Fe(II)/mg; 823 mM Trolox /100 g) were observed in mints fertilized with pigeon manure. Mint samples also had different antimicrobial activities against the studied microorganisms (eight bacteria and two fungi), especially Escherichia coli and Listeria monocytogenes.Öğe Effect of harvest time on physicochemical quality parameters, oxidation stability, and volatile compounds of extra virgin olive oil(Akademiai Kiado Rt, 2014) Çevik, Şerife; Özkan, Gülcan; Kiralan, Mustafa; Bayrak, AliThe aim of this study was to determine the changes in some physicochemical properties of olives (fruit weight, water content and oil content) and olive oils (total chlorophyll, carotenoid, pheophytin a, peroxide value and free acidity), and in the chemical properties (fatty acids, tocopherols, phenolics, oxidation stability and volatile profiles) of oils during ripening. Ripening indices (RI) of olive samples were 1.93 (unripe), 4.28 (ripe) and 5.89 (overripe). Most of the mentioned features changed with ripening. During ripening there was a sharp decrease in total chlorophyll, carotenoid and pheophytin a contents. An increase in oleic and linoleic acids and a decrease in palmitic acid were found in the fatty acid composition. Olive oils showed strong relations among oxidation stability, tocopherol content, total phenols content, and antiradical actvity of phenol extracts and these parameters decreased with maturation. Nevertheless, higher amounts of trans-2-hexenal were found in the oil from ripe olives than from unripe and overripe olives. On the other hand, the highest concentration of hexanal was found in the oil from overripe olives. In general, significant differences were observed in fruit weight, pigments, free acidity, fatty acid, tocopherol, and total phenolics contents, radical scavenger activity, oxidation stability, phenolic profile and volatile profile between the olive oils from the Gemlik cultivar at different stages of maturation.Öğe Effect of hazelnut roasting on the oil properties and stability under thermal and photooxidation(Springer, 2016) Özkan, Gülcan; Kıralan, Mustafa; Karacabey, Erkan; Çalık, Gürkan; Özdemir, Necla; Tat, Tuba; Bayrak, AliThe roasting process plays a key role in hazelnut oil production. The optimal roasting conditions for Delisava and Kara FA +/- ndA +/- k hazelnut cultivars were studied using response surface methodology (RSM). The maximum oil content and minimum values of peroxide value (PV), conjugated diene (K (232)), conjugated triene (K (270)) values of Delisava and Kara FA +/- ndA +/- k hazelnut cultivars were used to estimate the production of high-quality oils. The optimal roasting temperature and time for Delisava and Kara FA +/- ndA +/- k hazelnuts were 114.24 A degrees C for 27.21 min and 123.43 A degrees C for 22.12 min, respectively. Optimal oils were subjected to accelerated oxidation tests (Schaal oven test at 60 A degrees C) and photooxidation at daylight. Under thermal conditions, Kara FA +/- ndA +/- k oil possesses higher oxidative stability than Delisava oil according to PV, K (232) and K (270) values. Under photooxidation conditions, an opposite trend was noted when Kara FA +/- ndA +/- k oil exhibited lower oxidative stability in comparison with Delisava oil.Öğe Ege Bölgesi zeytinyağlarında altı karbonlu uçucu aroma bileşenlerinin belirlenmesi(2017) Kıralan, Mustafa; Kara, Hasan Hüseyin; Çalıkoğlu, Eda; Bayrak, AliYağ üretimi açısından önemli olan Ege bölgesi illerinden (Muğla, Aydın, İzmir ve Manisa) Gemlik, Memecik, Ayvalık, Uslu ve Domat zeytin çeşitlerinden 2007-2008 ve 2008-2009 dönemi olmak üzere 2 yıl hasat edilmiştir. Hasat edilen zeytinler laboratuvar tipi santrifüj sistem kullanılarak yağa işlenmiştir. Tepe boşluğukatı faz mikroekstraksiyon (HS-SPME) yöntemi yardımı ile yağlardan uçucu aroma bileşenleri ekstrakte edilerek gaz kromatografi-kütle spektrometre (GC-MS) cihazı ile bileşenlerin kalitatif ve kantitatif analizi yapılmıştır. Bu çalışmada, zeytinyağı kalitesi ile ilişkili olan altı karbonlu bileşenler belirlenmiştir. E-2-hekzenal ve hekzanal, çalışılan yağ örneklerinde en fazla oranda bulunan bileşenlerdir. 2007-2008 ve 2008-2009 hasat döneminde E-2-hekzenal bileşeninin sırası ile % 13.05-67.15 ve % 23.03-52.44 aralığında olduğu belirlenirken aynı hasat dönemlerinde % 6.70-39.34 ve % 11.23-59.81 arasında tespit edilen hekzanal bileşeninin, en yüksek salınan uçucu bileşenler arasında ikinci sırada yer aldığı görülmüştürÖğe Ege Bölgesi zeytinyağlarının fenolik bileşenleri(2018) Kara, Hasan Hüseyin; Kıralan, Mustafa; Çalıkoğlu, Eda; Bayrak, AliBu çalışmada, Türkiye’de başlıca zeytin yetiştiriciliği yapan Ege bölgesinin bazı illerinden (Muğla, Aydın, İzmir ve Manisa) 2 hasat dönemi (2007-2008 ve 2008-2009) süresince yerli zeytin çeşitlerinin (Gemlik, Memecik, Ayvalık, Uslu ve Domat) yağı incelenmiştir. Bu yağların toplam fenolik madde ve fenolik bileşimi belirlenmiştir. Yağların toplam fenolik madde içeriği, 2007-2008 hasat dönemi örneklerinde 23,69153,64 mg kafeik asit/kg, 2008-2009 hasat dönemi örneklerinde 16,18-136,22 mg kafeik asit/kg aralığında belirlenmiştir. Tüm zeytinyağı örneklerinde 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 döneminde 1,80-13,39 mg/kg, 1,26-19,50 mg/kg ve 2008-2009 hasat döneminde ise 1,76-11,66 mg/kg, 0,20-13,12 mg/kg aralığında en fazla miktarda değişen bileşenler olduğu saptanmıştı.Öğe Essential oil composition and antiradical activity of the oil of Iraq plants(Taylor & Francis Ltd, 2012) Kıralan, Mustafa; Bayrak, Ali; Abdulaziz, Omar Fawzi; Özbucak, TuğbaThis 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 alpha-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.Öğe Individual and combined use of rosemary and origanum in soybean oil as natural antioxidants(Taylor & Francis Inc, 2013) Aysel, Mehtap Bircan; Bayrak, Ali; Kiralan, Mustafa; Özbucak, TuğbaDried 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 degrees 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 degrees 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 degrees C.Öğe Introducing a traditional dairy product Kes: Chemical, microbiological, and sensorial properties and fatty acid composition(Wfl Publ, 2009) Cakir, Ibrahim; Coskun, Hayri; Akoglu, Ilker T.; Isleyen, M. Fatih; Kiralan, Mustafa; Bayrak, AliIn this study, it was aimed to determine the chemical, biochemical, microbiological and sensorial characteristics and fatty acid composition of Kes, traditionally produced in Bolu province in Turkey. The information on production of 'Kes' was collected from Bolu province in Turkey. Moreover, 20 samples were taken from the local bazaars in different periods in Bolu. These samples were taken to the laboratory, and the intended analyses were carried out. Also sensorial characteristics were described. In traditional way, first the cream of the milk is separated, and then it is processed for the yogurt. The yogurt is transferred in a cloth sack and allowed draining for one night. After that the content of the sack is dry salted and processed to obtain a cubic shape, which is called 'Kes', then dried under room temperature, or yogurt is churned and the whey (in Turkish, Ayran) is heated until content of the whey is precipitated. Then the precipitate is drained well and salted. After that some part of the salted precipitate is taken, shaped as cubic or conic and dried under room conditions. In the Key samples, mean dry matter was 61.59%, ash 13.66%, protein 32.42%, fat 6.30%, salt 13.26%, acidity 0.22% and pH 3.81. The mean ripening degree was 5.76% and lipolysis value 3.62 ADV (acid degree value) for Kes samples. Microbiological analysis showed that the mean number of total aerobic bacteria was 4.50 log cfu/g, molds and yeasts 3.99 log cfu/g, Lactobacillus spp. 3.80 log cfu/g and Streptococcus spp. 3.41 log cfu/g. The Kes samples contained neither coliform bacteria nor E. coli. Water activity (a(w)) of the Kes samples was 0.74 as mean of total samples. The color and appearance of Kes samples was dull-white, the structure was hard, and smell was acidic. The taste of the Kes samples was salty and acidic. The shapes of the samples were cubic, rectangular, triangle and conic. The predominant free fatty acids in the Kes samples were palmitic (C16:0) and oleic (C18:1) acids, followed by stearic (C18:0) and myristic (C14:0) acids.Öğe Oxidative and antiradical stabilities of two important virgin olive oils from Ayvalık and Memecik olive cultivars in Turkey(Taylor & Francis Inc, 2013) Kiralan, Mustafa; Bayrak, AliMemecik 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.Öğe Physicochemical properties and stability of black cumin (Nigella sativa) seed oil as affected by different extraction methods(Elsevier, 2014) Kiralan, Mustafa; Özkan, Gülcan; Bayrak, Ali; Ramadan, Mohamed FawzyBlack cumin (Nigella sativa) oil (BCO) was recovered using different extraction techniques including solvent free system (cold-pressing) and solvent extracted systems (Soxhlet and microwave assisted). Oils were analyzed for the composition of fatty acids and bioactive compounds (sterols, tocopherols, chlorophyll, carotenoid and phenolics profile) and for some physicochemical properties [free fatty acid, peroxide value (PV), refractive index, and ultraviolet (UV) absorption at K-232 and K-270]. Antiradical power (AP) of oils was also evaluated, wherein cold-pressed oil had stronger AP than solvent extracted oils. Phenolic profiles analyzed by HPLC revealed that thymoquinone was the main phenolic compound wherein high levels of benzoic and p-hydroxy benzoic acids were found in cold pressed-BCO. Oxidative stability (OS) of oils was evaluated during accelerated oxidation conditions (oven test at 60 degrees C and Rancimat test at 110 degrees C). The greatest induction period was 19.6h for Soxhlet-extracted BCO, and the lowest induction period was 3.48 h for cold-pressed BCO. PV of cold-pressed BCO reached 85.3 meq O-2/kg oil, while PV of the other extracted oils were under 27.0 meq O-2/kg oil at the end of storage period. (C) 2014 Elsevier B.V. All rights reserved.Öğe Volatiles in an endemic Allium specie: Allium tuncelianum by headspace solid phase microextraction(Taylor & Francis Ltd, 2013) Kiralan, Mustafa; Rahimi, Amir; Arslan, Neşet; Bayrak, AliThe 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.
