Nezahat Turfan¹

Dr. Nezahat Turfan¹


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 August 2024 in Food Science & Nutrition
Verified
Journal Article
Open access
NTNezahat Turfan¹
Nezahat Turfan¹
BKBeyhan Kibar
Beyhan Kibar
NDNazakat Davletova
Nazakat Davletova
HKHakan Kibar
Hakan Kibar
Salinity poses a significant abiotic stress that limits plant productivity, thereby posing a serious threat to agricultural sustainability and worldwide food security. Techniques that can overcome this problem are needed. Recent focus has been placed on employing organic substances like humic acid (HA) and amino acids, including L‐tryptophan (L‐TRP), to mitigate the negative effects of salt stress on cultivated plants. Accordingly, in this research, the impact of foliar applications of HA and L‐TRP, both separately and combined, on the growth parameters and biochemical properties of spinach subjected to salt stress was investigated. In the present study, eight treatments (1. control, 2. salt (NaCl), 3. HA, 4. L‐TRP, 5. HA + NaCl, 6. L‐TRP + NaCl, 7. HA + L‐TRP, and 8. HA + L‐TRP + NaCl) were investigated. The study showed that salt stress markedly reduced several growth properties in spinach, including plant height, number of leaves, leaf dimensions, and both fresh and dry weight. Additionally, it significantly lowered contents of chlorophyll (a, b, and total), carotenoid, polyphenol, lutein, anthocyanin, polyphenol oxidase, glycine betaine, relative water content, and the antioxidant enzyme activities (ascorbate peroxidase, catalase, peroxidase, and superoxide dismutase). On the other hand, significant increases were observed in sodium, chlorine, potassium, sulfur, zinc, nickel, proline, malondialdehyde, and hydrogen peroxide levels of spinach with salinity. Individual and combined applications of HA and L‐TRP positively influenced plant growth, relative water content, activities of antioxidant enzyme, chlorophyll, and mineral contents of spinach under both normal and saline conditions. In conclusion, the combined use of HA and L‐TRP under salt stress conditions is promising in mitigating the negative impacts of salinity and can be suggested as an effective alternative approach for cultivating spinach in saline environments.

27 November 2023 in Food Science & Nutrition
Verified
Journal Article
Open access
HKHakan Kibar
Hakan Kibar
BKBeyhan Kibar
Beyhan Kibar
NTNezahat Turfan¹
Nezahat Turfan¹
To extend the postharvest storage life of broccoli samples (Brassica oleracea L. var. italica), an exogenous application of citric acid (CA), salicylic acid (SA), and putrescine (PUT) was tested in multiple combinations (0.5 and 1 mM) at 4 ± 0.5°C and 90 ± 5% relative humidity (RH) for 21 days (d). The weight loss (WL), respiration rate (RR), total soluble solids (TSS), pH, color (L*, a*, b*, chroma, and hue angle), proximate and mineral contents, phenolic and flavonoid contents, and other biochemical properties of the treated and untreated broccoli samples were evaluated throughout the storage duration. The lowest WL was observed when exposed to 0.5 mM of PUT. 1 mM CA and PUT treatments were affected by RR, depending on storage conditions. The lowest TSS content was observed in broccoli samples treated with 0.5 mM CA among all treatments. The chroma value of the samples was preserved by the 0.5 mM SA treatment. The most abundant element in broccoli samples was potassium in the control application, followed by a 1 mM SA treatment. In addition, the protein content was the highest in the 1 mM PUT treatment. The highest vitamin C was determined in the 1 mM CA treatment, and the most abundant vanillic acid was found in broccoli exposed to the 0.5 mM and treatment. Glucose content was determined at the lowest level in the 0.5 mM SA treatment, while higher increases occurred in other treatments. In terms of these findings, 1 mM CA, 1 mM SA, and 1 mM PUT delay WL, RR, and color degradation and prolong the storage life of broccoli samples stored at 4 ± 0.5°C. It was concluded that the biochemical content, fresh weight, and green color of broccoli samples throughout postharvest and storage can be maintained longer by exogenous application of these natural compounds. Therefore, we recommend 1 mM PUT and 1 mM CA treatments to maintain the quality of broccoli by minimizing losses in morphological properties, mineral, and biochemical compositions during postharvest storage.

30 March 2021 in Yüzüncü Yıl Üniversitesi Tarım Bilimleri Dergisi
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APAysun Pekşen
Aysun Pekşen
AKAslı KURNAZ
Aslı KURNAZ
NTNezahat Turfan¹
Nezahat Turfan¹
BKBeyhan Kibar
Beyhan Kibar
Radioactivity in the environment occur due to natural, terrestrial, extra-terrestrial factors or caused by the human activity. Food stuffs that grown in the soil which containing radioactive elements may get deposited or absorbed in the foods. Wild growing mushrooms can accumulate many types of toxicological, nutritional and radioactive elements. So, mushrooms are considered as good bio-indicators to determine the environmental pollution caused by radiations. Knowing the levels of radioactivity in the food stuffs is of great importance for the protection of human health. In this study, the active concentrations of the naturally occurring 238U, 232Th, 40K nuclides and artificially occurring 137Cs nuclide were determined and annual effective doses and excess lifetime cancer risk values were calculated in mushrooms commonly consumed by the Turkish people. 15 types of mushroom samples were collected from different locations of Turkey. The results show that the activity concentrations of 238U, 232Th, 40K and 137Cs varied from 9.2±1.6 to 75.4±8.8 Bq kg-1, 10.9±1.6 to 76.3±8.9 Bq kg-1, 925.9±29.0 to 3848.0±73.2 Bq kg-1 and 6.1±1.1 to 2824.8±79.8 Bq kg-1, respectively. The mean total annual effective dose was found to be 11.5 μSv y-1. 40K radionuclide was the highest contributor to the total annual effective dose (5.35 μSv y-1). According to these values obtained, the mean excess lifetime cancer risk (ELCR) of mushrooms was determined as 4.6 x10-5 %.

28 December 2019 in Turkish Journal of Agriculture - Food Science and Technology
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Journal Article
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NTNezahat Turfan¹
Nezahat Turfan¹
Sezgin AyanSezgin Ayan
Sezgin Ayan
ŞAŞeyma Selin Akın
Şeyma Selin Akın
EAEnes Akın
Enes Akın
In this study, variation of some chemical components such as anthocyanin, β-carotene, lycopene, phenolic, nitrate, soluble protein, proline, glucose, sucrose and total carbohydrate level ad PAL activity in some wild and cultivated edible mushrooms was examined. For this, four different mushroom species (Agaricus campestris L., Cantharellus cibarius Fr., Hericium erinaceus (Bull.) Pers., Lactarius piperatus L. Pers) were supplied from local market, named Kuzeykent Semt Bazaar, in Kastamonu province of Turkey. Mushroom samples were collected from Araç, Daday, Devrekani and Tosya locations of Kastamonu. According to findings, the highest anthocyanin value and PAL activity were obtained from A. campestris collected from Arac location with 0.107 mg g-1 and 6.99 EU, respectively. The amount of β-carotene (2.297 mg g-1) and lycopene (0.644 mg g-1) was the highest in C. cibarius collected from Tosya location, however; proline, soluble protein, nitrate and glucose level were the maximum in A. campestris collected from Devrekani location with 149.61 µmol g-1, 55.49 mg, 159.963 mg g-1 and 29.36 µg g-1, respectively. While total carbohydrate was the highest in H. erinaceus collected from Araç location with 80.97 µg g-1, sucrose concentration was the maximum with 39.22 mg g-1 in H. erinaceus collected from Daday location. As a result, A. campestris collected from Devrekani location exhibited the highest nutrient in terms of chemicals analysed except anthocyanin and it was followed by H. erinaceus collected from Daday location. However, C. cibarius and H. erinaceus collected from Araç location had lower chemical components. It can be said that these mushroom species are valuable and important as major food sources and non-wood products for Kastamonu province.

15 March 2020 in Artvin Çoruh Üniversitesi Orman Fakültesi Dergisi
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NTNezahat Turfan¹
Nezahat Turfan¹
GSGamze Savaci
Gamze Savaci
TSTemel Sariyildiz
Temel Sariyildiz
In this present study, we investigated the chemical compounds in the fresh leaves of ancient walnut trees (Juglans regia L.) aged 25, 75, 100, and over 400 year. Under similar environmental conditions, the fresh leaves of walnut trees were collected and analysed for chlorophyll molecules as chlorophyll a, chlorophyll b and carotenoids, enzymatic compounds (ascorbate peroxidase (APX), catalase (CAT) and superoxide dismutase (SOD) activities) and non-enzymatic compounds (proline, total soluble protein, total phenolic compounds), flavonoid and reducing sugars (glucose, sucrose, total soluble sugar). In addition, the oxidative stress level was determined by measuring lipid peroxidation (MDA-malondialdehyde) and hydrogen peroxide (H2O2). Significant differences in the chemical composition of the fresh leaves were found between the 4 different tree age classes. In general, the results showed that mean chlorophyll pigments were increased with increasing the age. There was also a general trend that mean glucose and starch concentrations increased with the age, while mean sucrose concentration decreased, but no changes were noted for mean total soluble carbohydrate. On the other hand, mean SOD concentration decreased with increasing the age. Other chemical compounds (mean proline, total soluble protein, malondialdehyde, hydrogen peroxide, APX and CAT), however, did not show clear trends with the age. As a result, these pioneer study have provided valuable insight into the variation in the chemical constituents of walnut tree leaves in relation to the age, and it can be used to better understanding, managing and fighting against pathogens of walnut ecosystems in future studies.

31 May 2022 in Tekirdağ Ziraat Fakültesi Dergisi
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NTNezahat Turfan¹
Nezahat Turfan¹
Taşköprü garlic, which is among the Geographical Indications of Turkey, is one of the important sources of income for the people in the Kastamonu region. It (Allium sativum L.) has become an indispensable food in the kitchen with taste, a high peculiar pungent smell, a specific colour, flavon enhancing molecules. Also, it has been used for medicinal purposes due to having antioxidant capacity, sulphur compounds, and minerals. Moreover, it can preserve its superior properties for a long time due to its high dry matter compared to other garlic genotypes. This study was conducted to reveal the yield, storage duration, and nutritional elements of Taşköprü garlic bulbs grown in an open field (OF-TD; OF-KUC) and greenhouse conditions (GH-TD; GH-KUC) as well as to determine how some bioactive components including pigment, secondary metabolites, nitrogenous compound, simple reduced sugar, pyruvic acid, lipid peroxidation (MDA-malondialdehyde) and H2O2 (hydrogen peroxide), vary according to the growing environment in both cloves and fresh leaves. The results revealed that there were significant differences in the effects of habitat on all the parameters investigated (p