Browsing by Author "Kunter, Birhan"

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Ankara-kalecik Koşullarında Bazı Sofralık Üzüm Çeşitlerinin Olgunluk Aşamasında Toplam Antioksidan ve Toplam Fenolik Bileşik İçeriğinin Değişimi
(2023) Keskin, Nurhan; Gokçen, Ibrahım Samet; Kunter, Birhan
Bu çalışmada, Kalecik (Ankara) ekolojisinde yetiştirilen sekiz yerli (Yalova Misketi, Yalova İncisi, Uslu, Trakya İlkeren, Tekirdağ Çekirdeksizi, Köhnü, Horoz Karası, Barış), dokuz yabancı (Victoria, Royal, Ribol, Prima, Lival, Isabella, Big Perlon, Alphonse Lavallée, Kyoho) kökenli toplam 17 sofralık üzüm çeşidinin, 2018 ve 2019 hasat döneminde toplam antioksidan (TA) ve toplam fenolik (TF) bileşik içerikleri belirlenmiştir. Çeşitlerin teknolojik olgunluğa ulaşmış salkımlarından alınan tanelerinde spektrofotometre ile analizler gerçekleştirilmiştir. Çalışmaya konu olan üzüm çeşitlerinde TA ve TF bileşik içerikleri çeşit özelliği olarak farklılıklar göstermiştir. En yüksek TA içeriği 2019 yılında Horoz Karası (59.11 µmol trolox eş değeri (TE)/g) çeşidinde belirlenirken, en yüksek TF bileşik içeriği ise 2018 yılında yine Horoz Karası (814.36 mg gallik asit eşdeğeri (GAE)/100 g) çeşidinde belirlenmiştir. Labrusca genotipleri olan Isabella ve Kyoho TA ve TF bileşik içeriği bakımından vinifera çeşitlerine benzer özellikler göstermiştir.
Anom Approach for the Statistical Evaluation of Organic Acid Contents of Clones of the Grape Variety 'kalecik Karasi
(Hohere Bundeslehranstalt & Bundesamt Wein-& Obstbau Klosterneuburg, 2021) Keskin, Nurhan; Kunter, Birhan; Celik, Hasan; Kaya, Ozkan; Keskin, Siddik
Organic acids have an important effect on flavor, aroma and color in berries and wines of grapes and they also play an important role for the microbiological and biochemical stability of the wine. The variety 'Kalecik Karasi' is one of the exclusive red grape varieties of Turkey. The aim of this study is to evaluate and visualize the differences between the 23 clones of 'Kalecik Karasi' with respect to organic acids. As organic acids were considered: tartaric, malic, citric, succinic and fumaric acids. The berries of the vintages 2016 and 2017 were harvested with 23 % soluble solids and HPLC (High Performance Liquid Chromatography) was used to identify organic acid content. Using Analysis of Means (ANOM) method the mean of each group was compared to the overall or grand mean to identify statistically significant differences. Thus the differences between the 'Kalecik Karasi' clones in terms of organic acids were compared and visualized by this method. According to the results, for all organic acids, except for tartaric and fumaric acid, differences between means of clones and overall mean are statistically significant (p<0.05). Both ANOVA and ANOM can be appropriate for determining differences between the groups. However, ANOM provides a simple graphical representation for group means. Therefore, it can be concluded that this method can be suggested to visualize differences between the groups for easy interpretation.
Aromatic Composition Of Pink Skinned Grape Cultivar: Gülüzümü (V.vinifera L.)
(2018) Cantürk, Sevil; Kunter, Birhan; Keskin, Nurhan
Gülüzümü is a grape cultivar used for fresh consumption. In addition to table grape characteristics, itis also used for traditional must products thanks to its berry skin color and flavor properties. This variety, whichis one of the important genetic resources of Ankara province, come into prominence with its attractive “pink”skin color and unique “rosy” flavor. In this study, the aroma composition of Gülüzümü was investigated on thegrape material obtained from Ankara-Beypazarı district, which is the original ecology of the variety. Analysiswas carried out using solid-phase microextraction technique with gas chromatography and mass spectrometry.Results were expressed in peak area (%) as a mean value. A total of 28 volatile compounds were identified.These compounds included 5 acids, 5 alcohols, 2 C6 compounds, 3 terpenes, 1 C13 norisoprenoid and 12aldehydes and ketones. The quantities of other compounds were detected very low. The relative distribution ofthe aroma compounds was; C6 compounds 67.9%, aldehydes and ketones 10%, acids and alcohols 4.9%, terpenes2.5%, C13 norisoprenoids 0.3% and other compounds 9.6%. The C6-compounds (hexanal and 2-hexenal) thathave vegetal flavor had the highest values in total aroma composition of Gülüzümü. Although terpenecompounds are proportionally low in the aromatic composition, nerol, the main compound that contributes rosyflavor, was the compound that detected high amount. Benzene acetaldehyde (hyacinth), 2-ethyl hexanol (floral),benzene methanol (fruity), maltol (caramel), heptanoic acid (sour) and acetic acid (vinegar) were determined asproportionally important compounds in total aroma composition of Gülüzümü.
Asmada (Vitis Vinifera L.) İn Vitro I. Tip Kallus Eldesi Üzerine Çeşit, Besin Ortamı ve Eksplant Tipinin Etkisi
(2010) Kunter, Birhan; Keskin, Nurhan
Bu çalışmada; Kalecik karası, Öküzgözü, Erciş ve Cabernet Sauvignon üzüm çeşitlerinde ikincil bitki ürünü üretmek amacıyla elde edilen kallusların kalitesi üzerine; çeşit, besin ortamı ve eksplant tipinin etkisi araştırılmıştır. Eksplant kaynağı olarak sürgünlerin orta bölümünden alınan yaprak ayası ve boğum araları kullanılmıştır. Dikimler, 1.0 μM BAP (6-benzilaminopürin), 0.1 μM 2,4-D (2,4-diklorofenoksi-asetik asit), sakkaroz (%2) ve agar (% 0.8 ) ilave edilmiş MS ve Gamborg B5 katı temel besin ortamlarına yapılmıştır. Hazır besin ortamlarından MS besin ortamı saf su içerisine litreye 4.4 g, B5 ortamı ise 3.2 g katılarak hazırlanmıştır. Her iki besin ortamının da pH değeri 5.7’ye ayarlanmıştır. Kalluslar karanlıkta ve 25C’de inkübe edilmiş ve 21 gün ara ile iki defa alt kültüre alınmıştır. Araştırma sonucunda, kallus kalitesini ifade eden I. tip kallus oluşumunun besin ortamı, üzüm çeşidi ve eksplant tipine göre değiştiği belirlenmiştir. Çalışmada kullanılan iki farklı besin ortamından B5 besin ortamının, I. tip kallus oluşumu bakımından MS ortamına göre daha başarılı olduğu saptanmıştır. En yüksek I. tip kallus oluşumu gösteren üzüm çeşidi Cabernet Sauvignon (%74.73), en düşük I. tip kallus oluşumu gösteren üzüm çeşidi ise Öküzgözü (%23.20) olmuştur. Kullanılan eksplant dikkate alındığında, I. tip kallus oluşumu bakımından yaprak ayalarının boğum aralarına göre daha başarılı sonuçlar gösterdiği belirlenmiştir.
Asmada İn Vitro Melatonin Uygulamalarının Kallus Oluşumu İle Antioksidan Aktivite ve Toplam Fenolik Bileşik İçeriği Üzerine Etkisi
(2023) Keskin, Nurhan; Gokçen, Ibrahım Samet; Kunter, Birhan; Batuk, Mihriban; Yıldız, Sena; Kaya, Ahmet Çağlar
Bu çalışmada, Merlot ve Erciş üzüm çeşitlerine ait kallus kültürlerinde, Melatonin (MEL) uygulamalarının kallus oluşumu ile antioksidan aktivite (AA) ve toplam fenolik (TF) bileşik içeriği üzerine etkisi incelenmiştir. Başlangıç eksplantı olarak in vitro bitkiciklerden elde edilen boğum araları kullanılmıştır. Eksplantlar, pH değeri 5.7’ye ayarlanmış, 0, 100, 200 µmol.l⁻¹ MEL, 30 g l⁻¹ sakkaroz ve 8 g agar içeren Murashige ve Skoog (MS) katı besin ortamına dikilmiştir. Kültürler iklim odasında 25C’de 8/16 saat fotoperiyotta inkübe edilmiş ve 21 gün ara ile iki defa alt kültüre alınarak kallus çoğaltımı sağlanmıştır. Kallusların antioksidan aktivitesi demir indirgeme antioksidan gücü (FRAP) yöntemiyle spektrofotometrede 593 nm dalga boyunda okunarak µmol trolox eş değeri (TE) g⁻¹ olarak ifade edilirken, TF bileşik içeriği Folin-Ciocalteu reaktifi (FCR) kullanılarak spektrofotometrede 725 nm dalga boyunda okunmuş ve mg gallik asit eşdeğeri (GAE) g⁻¹ olarak ifade edilmiştir. Çalışma sonucunda MEL’in asmalarda kallus oluşumunu uyardığı ve TA ve TF bileşik içeriği üzerine etkili olduğu belirlenmiştir.
Clonaltrans-Resveratrol Potential in the Ripened Grapes Ofvitis Vinifera L. Cv 'kalecik Karasi
(Springer, 2020) Keskin, Nurhan; Kunter, Birhan; Celik, Hasan
In this study,trans-resveratrol (t-RSV; 3,5,4 '-trihydroxy-trans-stilbene) contents of the ripened berries of 23 clones of 'Kalecik Karasi' which is one of Turkey's leading red wine grape cultivars, grown in Ankara (Kalecik) were determined by HPLC. For this purpose; the berries were collected at 22-24 degrees Brix during 2016-2017 vintage seasons. Descriptive statistics fort-RSV content of clones were expressed as mean with their standard errors. One-way analysis of variance was performed for the comparison. Duncan multiple comparison test was used to determine the significant variances among clones. In addition, Analysis of Mean (ANOM) was also applied to determine the differences of the clones from the grand mean. As a result,t-RSV content of the clones ranged from 0.31 mg kg(-1)(Clone 22) to 1.67 mg kg(-1)(Clone 7) followed by Clone 6 with 1.12 mg kg(-1)and differences among the clones were statistically significant (p < 0.05).
Comparison of the Sugar and Organic Acid Components of Seventeen Table Grape Varieties Produced in Ankara (Türkiye): a Study Over Two Consecutive Seasons
(Frontiers Media Sa, 2024) Kunter, Birhan; Unal, Osman Batur; Keskin, Siddik; Hatterman-Valenti, Harlene; Kaya, Ozkan
Sugars and organic acids not only have a significant impact on taste balance and sensory acceptance by consumers but also play a crucial role in the chemical equilibrium of grape juices and wines. Therefore, this study aimed to quantify the content and composition of sugars and organic acids in 17 grape varieties over two consecutive years using high-performance liquid chromatography. The variability in all the parameters studied was strongly influenced by both the grape cultivars and specific years (p <= 0.05). In grape berries, the primary sugars identified were fructose and glucose, which ranged from 6.50 to 11.10 g/L and from 5.83 to 12.12 g/L, respectively, over the two years. However, sucrose was not detected in any of the grape varieties examined. For the two respective years, the highest titratable acidity (TA) was found in Tekirdag cekirdeksizi (TeCe) (0.89 and 0.90 g/L), while the lowest was detected in Victoria (Vi) (0.48 and 0.51 g/L). Total soluble solids (TSS) peaked in Horoz Karasi (HoKA) (21.90 degrees Brix), whereas it reached its lowest point in Big Perlon (BiPe) (14.1 degrees Brix). The tartaric acid content in the grape berries, ranging from 1.48 to 10.33 g/L for the two years, exhibited similar characteristics to malic acid, which ranged from 1.09 to 9.62 g/L and from 1.03 to 9.68 g/L for the two respective years. The succinic, malic, tartaric, citric, and oxalic acid contents were notably higher in the Kyoho (Ky) variety than in the other varieties. When examining the dendrogram of the contents of organic acid and sugar for similarities, it was evident that 16 out of the 17 grape varieties had a high degree of similarity, except for Alphonse Lavallee (AlLa) and HoKa. The similarity levels among the varieties ranged from 99.49% to 72.36%. The highest similarity (99.49%) was observed between the AlLa and Baris (Ba) varieties. The lowest similarity was observed among the AlLa, HoKa, and Ky varieties. In summary, this study underscores that certain table grape varieties grown in Ankara exhibit significant variations in valuable organic acids and sugars, which are associated with potential health benefits when considering human consumption.
Deciphering Terroirs' Code: Vineyard Site Selection for Phenolic Performance in 'kalecik Karası' Grape Cultivar (V. Vinifera L.)
(Springer, 2024) Canturk, Sevil; Kunter, Birhan; Keskin, Nurhan; Kaya, Ozkan
Understanding the complex interplay between environmental factors and grape quality is crucial for the viticulture industry, as it directly influences wine quality and the distinctiveness of products. This significance underpinned our comprehensive study, which aimed to dissect the relationships between 'terroir', including the altitude, regional climate, soil characteristics, vineyard management practice, and the composition of grapes in cv. 'Kalecik Karas & imath;' (Vitis vinifera L.). Six vineyard sites ranging from 115 to 1180 m altitude were studied. Total soluble solids (TSS, degrees Brix) titratable acidity, pH and color index of red grapes (CIRG) were evaluated as the main maturity indices and phenolic composition based on anthocyanin and tannin was analyzed. According to the results of the study, we deduced the critical importance of adopting region-specific viticultural practices tailored to the unique environmental conditions of each terroir. This approach not only optimizes grape quality but also accentuates the uniqueness of the wines produced, reflecting the inherent qualities of their origin. The highest altitude Nev & scedil;ehir (1180 m) showed high levels of total and extractable anthocyanin highlighting the region's favorable conditions for these compounds (355.26 mg kg(-1) and 364.00 mg kg(-1)), while exhibiting the second lowest skin tannin (1979.40 mg kg(-1) and 2180.78 mg kg(-1)) in both years. Particularly for cultivars like 'Kalecik Karas & imath;', our study demonstrated how specific terroirs could significantly affect their phenolic composition and, consequently, wine quality. By aligning viticultural practices with the distinct characteristics of each terroir, producers can enhance both the quality and distinctiveness of their wines. This emphasizes the necessity of ongoing research and adaptation in viticultural strategies to fully harness the potential of diverse grape varieties and terroirs, ensuring the production of high-quality wines that truly reflect their origin.
Determination of Phenolic Compound and Organic Acid Contens of Some Grape Varieties Grown in Hizan (Bidis) Province
(Kahramanmaras Sutcu Imam Univ Rektorlugu, 2020) Uyak, Cuneyt; Dogan, Adnan; Sensoy, Ruhan Ilknur Gazioglu; Keskin, Nurhan; Cavusoglu, Seyda; Cakmakci, Ozlem; Kunter, Birhan
Aim of this study was to determine phenolic compound and organic acid contents of 17 local grape varieties grown in Hizan (Bitlis) province of Turkey. Organic acid and phenolic compound amounts were determined via HPLC (High Performance Liquid Chromatography). Organic acids amount of grape varieties ranged from 1362.06 mu g g(-1) (Sapi Beyaz) to 4269.90 mu g g(-1) (Husni Beyaz) fortartaric acid and from1072.70 mu g g(-1) (Alaki) to 2858.69 mu g g(-1) (Kus Uzumu) for malic acid. Phenolic compound amounts of grape varieties ranged from 4.718 mu g g(-1) (Husni Beyaz) to 33.177 mu g g(-1) (Sapi Yesil) for gallic acid, from 6.293 mu g g(-1) (Beyaz Bineteti) to 20.201 mu g g(-1 )(Alaki) for vanilic acid, from 0.174 mu g g(-1 )(Beyaz Bineteti) to 2.830 mu g g(-1) (Alaki).for rutin, from 0.193 mu g g(-1) (Beyaz Bineteti) to 1.395 mu g g(-1 )(Kus uzumu) for protocatechuic acid, from 0.509 mu g g(-1) (Husni Beyaz) to 12.036 mu g g(-1) (Beyaz Guzane) for clorogenic acid, from 0.050 mu g g(-1 )(Siyah Guzane) to 0.485 mu g g(-1) (Husni Beyaz) for syringic acid, from 0.043 mu g g(-1) (Alaki) to 0.211 mu g g(-1) (Kirmizi Tayfi) for p-coumaric acid, from 0.041 mu g g(-1) (Beyaz Sinciri) to 1.238 mu g g(-1) (Siyah Guzane) for ferulic acid, from 0.023 mu g g(-1) (Beyaz Sinciri) to 1.083 mu g g(-1) (Kus Uzumu) for o(-)coumaric acid from 0.209 mu g g(-1) (Siyah Guzane) to 2.360 mu g g(-1) (Inek Memesi) for resveratrol, from 0.086 mu g g(-1) (Beyaz Sinciri) to 1.228 mu g g(-1) (Alaki) for florodiz.
The Effects of Callus Age, Uv Irradiation and Incubation Time on Trans-Resveratrol Production in Grapevine Callus Culture
(Ankara Univ, Fac Agr, 2009) Keskin, Nurhan; Kunter, Birhan
In this study, the effects of callus age, ultraviolet (UV) irradiation and incubation time were investigated for the induction of trans-resveratrol production in callus cultures of Kalecik karasi (Clone 12) Vitis vinifera L. grape cultivar. Part of leaves (similar to 1 cm(2)) were taken from one year old grapevines grown in greenhouse and then were cultured in Gamborg B-5 media including 2% saccarose, 0.8% agar, 1.0 mu M BAP (6-benzylaminopurine) and 0.1 mu M 2, 4-D (2, 4-dichlorophenoxy-acetic acid). After the second subculture, 12 and 15 days old callus tissues were exposed to 254 nm UV light at 10 cm distance from the source for 10 and 15 min. Trans-resveratrol was measured at 0, 24, 48 and 72 hours of incubation by using High Pressure Liquid Chromatography (HPLC). Trans-resveratrol concentration of control callus ranged from 0.56 to 0.96 mu g g fw(-1). The highest trans-resveratrol production was obtained from 12 and 15 days-old callus irradiated for 10 min. at the 48(th) hours of incubation (2.42 mu g g fw(-1)). Considering the highest value of trans-resveratrol concentration in controls and experiments, it was determined that UV irraditation in Kalecik karasi elicitated the trans-resveratrol production by 2.5 times.
Ercis Üzüm Çesidinin Kallus Kültürlerinde Uv Isını Etkisiyle Resveratrol Üretiminin Uyarılması
(2007) Kunter, Birhan; Keskin, Nurhan
Öz: Bu çalısmada; Ercis üzüm çesidine ait kallus kültürlerinde, ultraviyole (UV) ısını ile uyarılmıs kallus dokularında, bir stilben bilesigi olan resveratrol üretiminin uyarılması üzerine, UV ısını uygulama süresi, inkübasyon süresi ve kallus yasının etkisi incelenmistir. Kallus dokuları, serada yetistirilen çeliklerin yapraklarından elde edilmistir. Ortam olarak; %2 sakkaroz, % 0.8 agar, 1.0 μM BAP (6-benzilaminopürin) ve 0.1 μM 2, 4-D (2, 4- diklorofenosi-asetik asit) eklenmis Gamborg B-5 ortamı kullanılmıstır. Kalluslar, 21 gün ara ile iki defa alt kültüre alınmıstır. kinci alt kültürden sonra, 12 ve 15 gün yaslı kalluslara, steril kabin içerisinde petri kutularının kapakları açılarak, 10 cm uzaklıktan 10 ve 15 dakika süreyle 254 nm dalga boyuna sahip UV ısını uygulanmıstır. Uygulamanın ardından kalluslar 25 °C’de ve karanlık kosullarda inkübe edilmistir. Resveratrol üretiminin belirlenmesi amacıyla, Yüksek Basınçlı Sıvı Kromotografisi (HPLC) yönteminden yararlanılmıs, ölçümler 0., 24., 48. ve 72. saatlerde yapılmıstır. En yüksek resveratrol derisimi; 10 dakika UV ısını uygulanmıs, 12 gün yaslı kallus kültürlerinin 48. saatinde ölçülmüstür (66.39 μg/g YA). Genel olarak, 12 gün yaslı kallus kültürlerinde elde edilen resveratrol birikiminin 15 gün yaslı kültürlerden daha yüksek oldugu görülmüstür. Ayrıca, UV ısınının, her iki uygulama zamanında da resveratrol üretimini uyarmak için etkili oldugu ve böylece kallus kültürlerinde resveratrolün üretilebilecegi belirlenmistir.
Evaluation of Clonal Variability of Berry Phenolics in Vitis Vinifera L. Cv. Kalecik Karasi
(Springer, 2022) Keskin, Nurhan; Kunter, Birhan; Celik, Hasan; Kaya, Ozkan; Keskin, Siddik
In clonal grapevine populations, genetic factors may have a significant effect on the amount of phenolic compounds in the grape berries. Thus, the capacity of the clones to produce distinctive chromatic profiles can be improved. This paper describes the phenolic contents and composition of grape berries as well as relationships among them for Kalecik Karasi clones to reveal their wine quality potentials. Seven individual polyphenols were quantified using high-performance liquid chromatography. The clones showed a significant difference (5.01 mg kg(-1) protocatechuic acid and 18.80 mg kg(-1) gallic acid) in berry phenolic compounds. Cluster analysis and multidimensional scaling were performed, and results showed that clones were clustered into three groups regarding phenolic compounds in the berries. Based on the phenolic compounds, 18 of the 23 clones were clustered into a group. Clones 16, 13, 8, and 2 were grouped together, while clone 7 was separated from the others. Including and excluding clone 7, approximately 40% phenotypic variation and 80% similarity were observed in 'Kalecik Karasi' clones, respectively. There were positive correlations between clones 2, 6, 7, 9, and 13 and p-coumaric, ferulic, gallic, and protocatechuic acids, as well as between clones 3, 5, 10, 14, 15, 34, 16, 19, and 20 and q-coumaric, vanillic, and syringic acid contents. Thus, it can be stated that multivariate methods can be used for clonal selection, and exclusive clones can be selected with high values of phenolic compounds in the future.
Health From Grape by Resveratrol: Review
(Ortadogu Ad Pres & Publ Co, 2009) Keskin, Nurhan; Noyan, Tevfik; Kunter, Birhan
Resveratrol (3, 4', 5-trihydroxy-stilbene) is a phytoalexin of the stilbene group and is synthezed by grapevine species against biotic and abiotic stress conditions. Especially, it is synthezed in high concentrations in the shell of colored grape cultivars (0.30-0.14 mg/g fw; 9.30-78.50 mg/g dwt). After the discovery of its biochemical structure, resveratrol has been used in the prevention and the treatment of several diseases. Interest on this compound increased after finding its existence in grape and wine. Many medical and pharmacy literatures have emphasized that resveratrol has antifungal, antimicrobial, antitumor and antioxidant effects. Most of the studies about resveratrols are focused on its protective and inhibitory effects on cancer. Resveratrol decreases the risk of coronary heart attack by inhibiting platelet aggregation, reducing cholesterol level and displaying anti-inflammatory activity. In France, low mortality rate from coronary heart diseases depend on moderate amount of wine consumption (French paradox). In addition, recent studies stated that resveratrol had curative effects for Alzheimer's disease. Because it is resistant to heat, resveratrol preserves its own active form in foods. It is easily digested after ingestion and diffuses into blood rapidly. For the protective effect of resveratrol, consumption of 375 mL red wine or 50 grape berries a day or taking resveratrol extract supplements may be recommended. In this review, the protective effect of resveratrol, a protector for grapewine against stress factors, on several diseases of humans such as cancer, heart attack, etc. were discussed with the review of recent literatures.
Induction of Resveratrol Via Uv Irradiation Effect in Ercis Callus Culture
(Ankara Univ, Fac Agr, 2007) Keskin, Nurhan; Kunter, Birhan
In this study, the effect of ultraviolet (UV) irradiation time, incubation time and callus age were investigated for resveratrol induction which is a stilbene compound, in callus cultures of 'Ercis' grape cultivar (Vitis vinifera L.). Callus tissues were obtained from the leaves of the cuttings grown in greenhouse. Gamborg B-5 media including 2% saccarose, 0.8% agar, 1.0 mu M BAP (6-benzylaminopurine) and 0.1 mu M 2, 4-D (2, 4dichlorophenoxy-acetic acid) was used as culture media. Callus tissues were sub cultured two times with 21 days intervals. After the second subculture, 12 and 15 days old callus tissues were exposed to 254 nm UV light at 10 cm distance from the source for 10 and 15 min by opening covers of the petri dishes in sterile cabin. After UV treatment, callus tissues were incubated at 25 degrees C and in dark conditions. High Pressure Liquid Chromatography (HPLC) was used for determining of resveratrol production and concentrations were recorded at 0, 24, 48 and 72 hours after beginning of incubation. The highest resveratrol concentration (66.39 mu g/g FW) was determined at 48 hours of 12 days-old callus cultures irradiated for 10 minutes. Generally, resveratrol accumulation in 12 days-old callus cultures was higher than that of 15 days-old. Both 10 min and 15 min UV irradiation periods were found to be effective for induction of resveratrol production and thus callus cultures could be convenient for resveratrol production.
Karaerik (Ci̇mi̇n) Klonlarının Toplam Fenolik ve Antioksidan İçerikleri Bakımından Karşılaştırılması
(2018) Kunter, Birhan; Keskin, Nurhan; Oguz, Dilhem; Karadoğan, Birol; Kalkan, Nalan Nazan
Üzüm, insan sağlığı üzerine olumlu etkileri olan fenolik bileşikler ve antioksidanlarca zengin gıdalariçerisinde değer verilen bir yere sahiptir. Fenolik bileşikler ve antioksidanlar, bileşiminde bulunduklarıüzüm ve üzüm ürünleri yoluyla beslenmeye katıldıklarında bugün bilinen mekanizmalarla insan vücudunazarar veren serbest radikalleri yakalamakta, oksidatif hasara neden olan substratın oksidasyonunu büyükölçüde geciktiren veya engelleyen karşı duruşa hizmet etmektedirler. Bu çalışmada Türkiye asma genpotansiyeli içerisinde Kuzey Doğu Tarım Bölgesi’nin yegâne ve özgün standart sofralık çeşidi olarakönemli Karaerik (Cimin) üzüm çeşidine ait klonlar (Klon 13, Klon 15, Klon 18, Klon 19, Klon 23 ve Klon30), toplam fenolik ve antioksidan özellikleri bakımından karşılaştırılmıştır. Çalışmalardaspektrofotometrik yöntemler kullanılmıştır. Elde edilen bulgulara göre, klonların toplam fenolik bileşikiçerikleri 1.15 mg gallik asit eşdeğeri (GAE) g⁻¹ (Klon 18) ile 2.20 mg GAE g⁻¹ (Klon 13) arasındadeğişirken, antioksidan içerikleri 147.37 μg 100 g⁻¹ (Klon 18) ile 190.05 μg 100 g⁻¹ (Klon 15) arasındadeğişim göstermiştir.
Mineral Content of Berries in Native Grape Cultivars Grown in Mid-Black Sea Zone
(2019) Keskin, Nurhan; Cangi, Rüstem; Sucu, Seda; Altıncı, Neval Topcu; Kunter, Birhan; Yagcı, Adem
Fruits present safe and healthy nutrition in the human diet. They are rich sources of certain macro and micronutrients. Environmental factors such as temperature, rainfall, sunshine, wind, soil and many other growing conditions effects chemical composition of the berries. The present study was conducted to investigate 24 grape cultivars from the Mid-Black Sea zone in terms of berry mineral composition. Analysis was performed according to official methods procedure and the contents of Phosphorus (P), Calcium (Ca), Magnesium (Mg), Manganese (Mn), Iron (Fe), Copper (Cu), Zinc (Zn), Boron (B) and Selenium (Se) were determined by ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy) and Potassium (K) was measured by AAS (Atomic absorption spectroscopy). The results indicated that the mineral composition of grapes differ according to genotype.
A Study on Total Phenolics and Vitamin C Contents of Kalecik Karasi (Vitis Vinifera L.) Clones
(Univ Agriculture, Fac veterinary Science, 2014) Keskin, Nurhan; Celik, Hasan; Kunter, Birhan; Keskin, Siddik
In this study total phenolic and vitamin C contents of the fully ripe berries of 23 clones of Kalecik Karasi which is one of the leading Turkish local red-wine grape cultivar originally grown in Kizilirmak valley near Kalecik/Ankara region were examined under the clone selection project supported by TUBITAK (Project Nr: 107 O 731). High-pressure liquid chromatography (HPLC) was used for vitamin C and spectrophotometer for total phenolics estimation. One way ANOVA was used to compare means of clone for their total phenolic and vitamin C contents. In addition to this univariate method, hierarchical cluster analysis was performed to identify similarity levels among the clones by considering total phenolics and vitamin C content together. Differences among the clones were found statistically significant for both characteristics. Total phenolic contents of the clones varied from 3.310 mg (clone 21) to 3.389 mg (clone 6) as GAE g fw. Vitamin C content ranged from 14.010 mg (clone 6) to 16.500 mg (clone 19) in 100g fw. Furthermore, similarity level for all clones was 83.1% that means variation rate is about 17% among the clones. As a summary of whole data, the first three performing clones are 6 (3.389 mg), 10 (3.374 mg) and 1 (3.365 mg) for total phenolics, and 19 (16.500 mg), 9 (16.020 mg), and 21 (16.015 mg) for vitamin C contents of the berries.