Yazar "Tuncay, Ozlem" seçeneğine göre listele
Listeleniyor 1 - 6 / 6
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe THE EFFECT OF NITROGEN SOURCES ON YIELD AND QUALITY OF SALAD ROCKET GROWN IN DIFFERENT MONTHS OF THE YEAR(Taylor & Francis Inc, 2011) Tuncay, Ozlem; Esiyok, Dursun; Yagmur, Bulent; Okur, BulentThe effects of months of the year and nitrogen (N) sources on salad rocket (Eruca sativa Mill.) yield, quality, and nitrate accumulation was investigated during the years 2002 and 2003. In both years, seeds were sown on the first day of April, May, June, July, August and September. Three different nitrogen sources were used: farmyard (cattle) manure (100 tonnes center dot ha-1), calcium nitrate [Ca(NO3)2]-15.5% N (150 kg N center dot ha-1) and ammonium sulfate [(NH4)2SO4)]-21% N (150 kg N center dot ha-1). Yield, leaf color, dry matter, vitamin C and total glucosinolate content and nitrate accumulation was assessed. Growing months affected all the assessed parameters significantly both years, with the exception of hue angle in 2003, whereas nitrogen source only influenced yield and nitrate accumulation in 2003. In both years the highest yield was obtained in April, but vitamin C and total glucosinolate contents were higher during summer months, and leaves were slightly darker colored. Chemical fertilizers increased the yield compared to farmyard manure; however, they also increased nitrate accumulation slightly, without any significant difference between them. Nitrate accumulation never exceeded 300 mg kg-1 fresh weight (FW), which is well below the acceptable daily intake of 3.7 mg nitrate per kg-1 bodyweight set by European Commission's Scientific Committee on Food.Öğe The Effect of Olive Leaf Addition on Antioxidant Content and Antioxidant Activity of "Memecik" Olive Oils at Two Maturity Stages(Wiley, 2013) Sevim, Didar; Tuncay, Ozlem; Koseoglu, OyaIn this study, the effects of leaf addition, maturity stage and storage on the antioxidant content and activity of olive oils (cv. Memecik) were investigated in the 2008/09 and 2009/10 crop seasons. Olive fruits were harvested at two different maturity stages (early and late), and the leaves of the same cultivar were added at different rates (0, 1, and 3 %) prior to oil extraction. After extraction, the oil samples were stored for 18 months and total chlorophyll, alpha-tocopherol, total phenolic content and the antioxidant activity [DPPH center dot (2,2-diphenyl-1-picrylhydrazyl) and ABTS(center dot+) (2,2-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid) radical scavenging] were determined at 6 month-intervals. Olive leaf addition induced a significant increase in total chlorophyll, alpha-tocopherol, total phenolic content, and antioxidant activities in both years (P < 0.001). During the storage period antioxidant content and antioxidant activities in the oils significantly decreased in both years (P < 0.001). However, the oils to which leaf material was added had higher antioxidant contents and activities than those without leaf material addition at the end of the 18-month storage period. After storage, the antioxidant content and DPPH center dot radical scavenging activity of control (0 %) samples were lower than those in the leaf added samples (3 %). The data obtained from this study suggested that the addition of olive leaf to oils allowed more functional olive oils with higher antioxidant contents.Öğe Effects of foliar zinc applications on some yield parameters and essential oil constituents of the mastic tree (Pistacia lentiscus var. chia Duham.)(Elsevier, 2022) Bayram, Seda E.; Isfendiyaroglu, Murat; Tuncay, OzlemMastic tree (Pistacia lentiscus var. chia Duham.) is an important medicinal aromatic plant which is being culti-vated without any regular fertilization generally. Foliar Zn applications have great importance for many com-mercial plant species because of their important role in metabolic activities. In this study, the effects of foliar ZnSO4 sprayings (0, 0.2, 0.4, 0.8%) applied at 50% and 100% leafing stages, on some yield parameters and essential oil composition of mastic tree were assessed. A field experiment was carried out for two consecutive years at Ege University, Turkey. Mastic resin yield was more than doubled with 0.8% Zn particularly in the second year. The highest leaf Zn content was measured as 187.8 mg l- 1 with 0.8% zinc spraying while it was 35.4 mg l- 1 in unsprayed trees at 100% leafing in the first year. Leaf essential oil and alpha-tocopherol contents were not significantly influenced by different Zn levels and leafing stages in both years. As for the major essential oil constituents, 13-myrcene (62.4%), germacrene-D (14.3%), alpha-terpinenyl acetate (5.52%), t-caryophyllene (2.1%) and alpha-pinene (1.4%) were determined. Zinc sprayings increased the 13-myrcene, germacrene-D and alpha-pinene contents particularly at 100% leafing in the first year. In mastic tree two consecutive applications of Zn seems to be necessary for reaching to desirable leaf Zn contents. Application of 0.8% Zn or more would be proper to increase the contents of most parameters assessed.Öğe Postharvest logistics performance of fresh fig varieties in Turkey(Elsevier, 2019) Ertan, Birgul; Senkayas, Huseyin; Tuncay, OzlemDemand for fresh food is increasing day by day as people want to consume healthy, quality and fresh vegetables and fruits. So, the main mission of supply chains is to deliver secure and fresh food overcoming postharvest losses. Fresh fig is a kind of perishable fruit with is very short durability period. Diversification of fresh fig market and its trade will strengthen the status of fresh fig in domestic and international markets. Post harvest storage and transport (logistics) conditions cause various damage and quality losses in fresh figs that continue to ripen. Therefore, factors such as storage temperature, humidity, transport containers, water losses due to mechanical damage and vibration of vehicles are important. This project was conducted in order to determine the most appropriate fresh fig varieties as an exportation alternative to "Bursa Siyaht" and to demonstrate changes in quality during storage and shelf-life periods after storage. "Siyah Orak", "Goklop" and "1100" fig varieties at the Fig Research Institution in Aydin were used as materials. During harvest fruit were directly placed into their storage packages (into nespacks) and stored at 3 +/- 1 degrees C for 20 days in cold storage condition. In addition, the samples taken from cold storage were kept for two days at 20 degrees C to determine their shelf-life periods. During the studies in 2012, 2013 and 2014 the following data was collected: weight loss during storage and shelf-life periods, firmness by texture analysis, total soluble solids, titratable acidity, maturity rate, pH, L, a, and b skin and flesh color values. During the studies on storage and shell-life period, it was shown that the fruit harvested at their coloring stages of 2/3 and 1/3 of hard-ripe fig variety was more durable than other varieties. It was also concluded that since the fruit harvested during the ripening period when 1/3 of their skin get colored are so small, they can be commercialized with different packaging materials.Öğe Relationships between nitrate, chlorophyll and chromaticity values in rocket salad and parsley(Academic Journals, 2011) Tuncay, OzlemThe relationships between nitrate concentration, total chlorophyll, chlorophyll a and b concentrations, chromaticity values L*, a*, b*, hue and chroma in parsley (Petroselinum crispum Mill.) and rocket salad (Eruca sativa Mill.) were investigated. Every month, during 2004 and 2005, three samples for each leafy vegetable were obtained from the market, and after the measurement of colour with a tristimulus colorimeter as Commission Internationale De L'eclairage L* a* b*, nitrate, total chlorophyll, chlorophyll a and b concentrations were determined analytically. Correlation analysis showed that in both vegetables, there were highly significant correlations (P<0.001) between nitrate, total chlorophyll, chlorophyll a, L* and a* values, and it was possible to estimate total chlorophyll and nitrate concentrations by L* or a* values.Öğe Yield and quality of garden cress affected by different nitrogen sources and growing period(Academic Journals, 2011) Tuncay, Ozlem; Esiyok, Dursun; Yagmur, Bulent; Okur, BulentThe effects of different months of the year and nitrogen sources on garden cress (Lepidium sativum L.) yield, quality and nitrate accumulation were investigated during the years 2002 and 2003. In both years, seeds were sown on the first days of September, October, November, January, February and March. Three different nitrogen sources were used: Farmyard (cattle) manure (100 ton.ha(-1)), Ca(NO3)(2)-15.5% N (150 kg N.ha(-1)) and (NH4)(2)SO4)-21% N (150 kg N.ha(-1)). Yield, leaf color, dry matter, vitamin C, total glucosinolate content and nitrate accumulation were assessed. No interaction between sowing date and nitrogen form was observed for any of the assessed parameters. Growing period affected all parameters significantly. Plants obtained from January and February sowings resulted in better yield, leaf color, dry matter and vitamin C content. But the nitrate contents also increased. Highest total glucosinolate content was observed during the warmer months. Nitrate nitrogen application increased yield, leaf greenness, vitamin C and nitrate content while farmyard manure application raised dry matter and total glucosinolate contents. Nitrate content of the garden cress plants did not exceed 391 mg kg(-1) fresh weight, which is below the accepted daily intake of 3.7 mg nitrate per kg(-1) bodyweight set by European Commission's Scientific Committee on Food.
