Beslenme ve Diyetetik Bölümü Koleksiyonu

Permanent URI for this collectionhttps://hdl.handle.net/20.500.12514/223

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Citation - WoS: 62
Citation - Scopus: 70
Changes in volatile compounds, sugars and organic acids of different spices of peppers (Capsicum annuum L.) during storage
(FOOD CHEMISTRY, 2020) Korkmaz, Aziz; Atasoy, Ahmet Ferit; Hayaloglu, Ali Adnan
Changes in sugars, organic acids and volatile compounds (VC) of red pepper flakes (RPF), traditional (TRI), and industrial (INI) isot peppers were evaluated during one year storage at the room condition. The changes in the flavor components were significantly affected by the production methods and storage time. Glucose content decreased gradually along storage and reduced by about 21.23, 47.22 and 56.65% for TRI, INI and RPF, respectively. However, fructose decreased significantly only in RPF (11.29%). Citric and succinic acids exhibited slight changes, but malic acid showed an increasing trend, especially in RPF (4-fold). Most of the VC in all samples decreased or disappeared after storage. The major quantitative losses in these compounds were found in TRI during the first 3 months as 81.76%. The storage was found to be caused deterioration flavor properties in red pepper spices and revealed the importance of appropriate storage conditions.
Effect of Agro-Industrial Wastes on Production of Laccase in Submerged Cultures of Some Wild Mushrooms
(Elsevier Science Bv, 2012) Acay, Hilal; Keskin, Cumali; Kacar, Semra
Citation - WoS: 33
Citation - Scopus: 33
The effects of production methods on the color characteristics, capsaicinoid content and antioxidant capacity of pepper spices (C. annuum L.)
(Elsevier, 2021) Korkmaz, Aziz; atasoy, Ahmet Ferit; Hayaloğlu, Ali adnan
The effects of production methods for red pepper flakes (RPF) and traditional (TRI) and industrial (INI) isot spices were evaluated with respect to the carotenoid and capsaicinoid contents, extractable color (ASTA color), surface color parameters, nonenzymatic browning (NEB), and the DPPH free radical-scavenging capacity of fresh red Capsicum (FRC). The measured characteristics were significantly affected by the processing methods used. RPF exhibited the highest antioxidant activity and best color quality in terms of carotenoid content, which was the highest; ASTA value; surface color intensity; and NEB, which was the lowest. In contrast, INI-processing methods resulted in poor color quality, causing the maximum increase in NEB. The concentration of capsaicinoid increased at the end of TRI processing, whereas it decreased in the two other methods. These results suggest that the traditional production method for isots prevents excessive destruction of their color attributes and contributes to the desirable characteristic browning.
Citation - WoS: 33
Citation - Scopus: 33
The effects of production methods on the color characteristics, capsaicinoid content and antioxidant capacity of pepper spices (C. annuum L.)
(Food Chemistry, 2021) Korkmaz, Aziz; Atasoy, Ahmet Ferit; Hayaloglu, Ali Adnan
The effects of production methods for red pepper flakes (RPF) and traditional (TRI) and industrial (INI) isot spices were evaluated with respect to the carotenoid and capsaicinoid contents, extractable color (ASTA color), surface color parameters, nonenzymatic browning (NEB), and the DPPH free radical-scavenging capacity of fresh red Capsicum (FRC). The measured characteristics were significantly affected by the processing methods used. RPF exhibited the highest antioxidant activity and best color quality in terms of carotenoid content, which was the highest; ASTA value; surface color intensity; and NEB, which was the lowest. In contrast, INI-processing methods resulted in poor color quality, causing the maximum increase in NEB. The concentration of capsaicinoid increased at the end of TRI processing, whereas it decreased in the two other methods. These results suggest that the traditional production method for isots prevents excessive destruction of their color attributes and contributes to the desirable characteristic browning.
Citation - WoS: 15
Citation - Scopus: 17
Electrocatalysis property of CuZn electrode with Pt and Ru decoration
(International Journal of Hydrogen Energy, 2021) Toprak Döşlü, Serap; Döner, Ali; Yıldız, Reşit
Electrocatalysis properties strongly depend on the interaction of metallic particles and this interaction enables to change the electronic structure of alloys which enhances the catalytic activity. This property is the key factor in the developing of cost-effective and efficient Hydrogen Evolution Reaction (HER) electrocatalysts for sustainable hydrogen production. In this study, novel electrocatalysts which are decorated with Pt and Ru have been developed for HER electrocatalysis. Microscopic analysis such as scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) and atomic force microscopy (AFM) are performed to determine the morphological and compositional structures. Electrocatalysis properties are evaluated by cathodic current-potential curves, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) in 1.0 M KOH solution. Chronoamperometry (CA) and cycle tests are used for stability/durability of electrocatalysts. Results show that a small onset potential of the porous Cu/Ni/CuZn–Pt is obtained for HER. Exchange current density and polarization resistance are found to be 5.39 mA cm−2 and 2.0 Ω cm2 at overpotential of −100 mV for porous Cu/Ni/CuZn–Pt, respectively, indicating that Cu/Ni/CuZn–Pt is higher electrocatalytic properties than the others. Moreover, very low overpotentials at 10 and 40 mA cm−2 are obtained on porous Cu/Ni/CuZn–Pt compared with porous Cu/Ni/CuZn–Ru and Cu/Ni/CuZn. Porous Cu/Ni/CuZn–Pt also displays excellent stability/durability in test solution. The remarkable electrocatalysis properties of porous Cu/Ni/CuZn–Pt can be explained due to high porous structure, leaching of Zn from the deposit, intrinsic activity of Pt as well as changing in the electronic structure. It should be considered that porous Cu/Ni/CuZn–Pt is of high corrosion resistance in test solution for 120 h, which makes it good candidate for HER.
Citation - WoS: 2
Citation - Scopus: 2
Electrochemical Behavior of Pt Nano-Particles Dispersed on Cu/Ni Electrode in Alkaline Environment
(Pergamon Elsevier Science Ltd, 2024) Doslu, Serap Toprak; Doner, Ali
The development of a low-cost Pt-based electrocatalyst for industrial water splitting is important. In this study, to prepare cost-efficient Pt-based electrocatalyst for hydrogen evolution, Cu electrode is deposited with nickel (Cu/ Ni) and this surface is modified with Pt nanoparticles by electrodeposition method (Cu/Ni-Pt). The surface properties of the produced electrocatalysts are studied via X-ray diffraction (XRD), scanning electron spectroscopy (SEM), energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Characterizations demonstrated that the coating is homogeneous and compact. Hydrogen evolution and corrosion behaviors of prepared electrode (Cu/Ni-Pt) are examined in 1.0 M KOH solution using cyclic voltammetry (CV) and cathodic and anodic current-potential curves, electrochemical impedance spectroscopy (EIS). Tafel slope is determined to be 133 mV dec(-1) on Cu/Ni-Pt. Very high exchange current density (5.65 mA cm(-2)) and very low charge transfer resistance (0.91 Omega cm(2) at 1.05 V vs RHE) are measured again on this electrocatalyst. High activity is due to intrinsic activity of Pt and synergistic interaction of Pt and Ni. Besides, Cu/Ni-Pt exhibits so stable structure over 4 h without any current densities decay as well as showing good corrosion performance after long-term immersion times and these properties make it possible electrocatalyst with high corrosion resistant and activity in the water electrolysis systems.
Citation - WoS: 14
Citation - Scopus: 14
Experimental and theoretical study on hydrogen production by using Ag nanoparticle-decorated graphite/Ni cathode
(International Journal of Energy Research, 2021) Yıldız, Reşit; Doğru Mert, Başak; Karazehir, Tolga; Gurdal, Yeliz; Toprak Döşlü, Serap
In this study, graphite (G) electrode was coated with nickel and decorated with silver nanoparticles (G/Ni/Ag) with the help of galvanostatic method, and electrodes were used as a cathode in alkaline water electrolysis system. The characterization was achieved using X-ray diffraction and field emission scanning electron microscopy. Hydrogen evolution performance of electrodes was investigated via cyclic voltammetry, chronoamperometry, cathodic polarization curves, and electrochemical impedance measurements. Electrochemical results showed that hydrogen production efficiency significantly increased and charge transfer resistance decreased via G/Ni/Ag. The electrochemical water splitting performance of G/Ni/Ag, was established in a joint experimental and computational effort. Water and proton adsorption on Ag-decorated Ni surface were investigated using density functional theory. Electronic structure calculations identified the role of Ag adatom and Ni surface on water and proton adsorptions. From the computational studies, O in water was more reliable to adsorb at the bridge position of the Ag and Ni atoms, leading improved orbital overlap between H and Ni atoms and maximized chemical and physical interactions between the H2O molecules. Therefore, the Ag-decorated Ni(111) surface provides preferable adsorption site for the O atom in water and direct interactions between water Hs and available surface Ni atoms promote water dissociation.
Citation - WoS: 2
Citation - Scopus: 2
Investigation of the Effects of Apigenin, a Possible Therapeutic Agent, on Cytotoxic and SWH Pathway in Colorectal Cancer (HT29) Cells
(Advanced Pharmaceutical Bulletin, 2023) Unsal, Velid; Mustafa Cicek, Arif Emre, Adem Doganer
Purpose: Colorectal cancer (CRC) is one of the most common and fatal malignancies in humans, still leading to serious morbidity and mortality. We here aimed to investigate the effects of flavonoid apigenin, which is considered to have anti-tumoral activity on CRC with high epidemiological prevalence, on cell proliferation and cell survivals, and the positive and negative dose-dependent effects of genetic or mutational alterations in SWH pathway components on HT29 CRC cell lines. Methods: Human colon cancer cell lines HT-29 were commercially available. In each flask, 5 groups were formed, each of which consists of 5,000 cells for different dose groups and the cells were plated. After a 24 and 48 h incubation period, cytotoxicity values were measured by MTT assay and gene expression was assessed by real-time polymerase chain reaction (PCR) analysis method. Results: Application of 12.5 and 25 nM of apigenin significantly increased cell death in HT29 cell lines. LATS1, STK3 and TP53 gene expression decreased in the same dose groups compared to control and other groups. Conclusion: It has been concluded that TP53 gene is strongly correlated with LATS1 and STK3 genes among the SWH pathway factors in the progression of CRC and could be used as an important marker for early detection of malignant transmission. In addition, it may be effective in CRC cases especially when 25 nM of apigenin applies for therapeutic purpose.
Investigation of the hydrogen evolution on Ni deposited titanium oxide nano tubes
(Corrosion Science, 2012) Altunbaş Şahin, Ece; Doğru Mert, Başak; Toprak Döşlü, Serap; Kardaş, Gülfeza
Titanium oxide nano tubes (TiOx) were prepared by the electrochemical anodizing method from at different process time and different potential in 0.1 M HF solution. Their morphologies were determined with surface photographs and scanning electron microscopy (SEM) images. Ni nano particles were deposited in conductive TiOx nano tubes arrays via pulsed electrodeposition method. Their catalytic activity towards the hydrogen evolution reaction (HER) was assessed by recording cyclic voltammetry technique, cathodic currentepotential curves, hydrogen gas volumes and electrochemical impedance spectroscopy techniques. The highest HER activity thought the studied is observed on the TiOx(30)-Ni.
Citation - WoS: 33
Citation - Scopus: 36
Natural phytotherapeutic antioxidants in the treatment of mercury intoxication-A review
(Tabriz University of Medical Sciences, 2018) Unsal V.
Heavy metals taken into the organism can make the toxic effects on the metabolism in various ways. For example, they may interact with proteins to alter and inhibit their enzymatic and structural functions. Mercury is one of the toxic elements that are widely distributed in nature. Mercury toxicity poses a serious threat to human health. It is an element that causes oxidative stress to increase in individuals, leading to tissue damage. Oxidative stress is the result of the imbalance between the production of oxidative species and cellular antioxidant defense. Phytotherapy continues to play an important role in health care. Natural phytotherapeutic antioxidants, exhibit a broad sequence of biological impacts, including anti-oxidative stress, anti-aging, anti-toxicicity and anticancer. Many studies have also shown that the phytotherapeutic agents play an important role in the removal of mercury from the tissue and in reducing oxidative stress. Our goal in this review was to investigate alternative ways of extracting the mercury in the tissue. © 2018 The Authors.
Polyindole top coat on TiO2 sol–gel films for corrosion protection of steel
(Corrosion Science, 2013) Toprak Döşlü, Serap; Doğru Mert, Başak; Yazıcı, Birgül
The protection efficiency of polyindole film on stainless steel was enhanced via titanium dioxide precoating. The characterization of coatings was achieved by nuclear magnetic resonance and Fourier-transform infrared spectra. The surface morphology of electrodes was monitored with scanning electron microscope. The corrosion performance was investigated in 3.5% NaCl solution by electrochemical impedance spectroscopy and potentiodynamic measurements. The quantum calculations were employed, and theoretical parameters were determined. Results showed that the correlation between experimental and theoretical parameters. The high protection efficiency was observed against corrosion on the steel surface via forming a protective polyindole top coated titanium dioxide film.
Citation - WoS: 206
Citation - Scopus: 257
The Role of Natural Antioxidants Against Reactive Oxygen Species Produced by Cadmium Toxicity: A Review
(TUOMS PRESS, 2020) Unsal, Velid; Dalkıran, Tahir; Çiçek, Mustafa; Kölükçü, Engin
Cadmium (Cd) is a significant ecotoxic heavy metal that adversely affects all biological processes of humans, animals and plants. Exposure to acute and chronic Cd damages many organs in humans and animals (e.g. lung, liver, brain, kidney, and testes). In humans, the Cd concentration at birth is zero, but because the biological half-life is long (about 30 years in humans), the concentration increases with age. The industrial developments of the last century have significantly increased the use of this metal. Especially in developing countries, this consumption is higher. Oxidative stress is the imbalance between antioxidants and oxidants. Cd increases reactive oxygen species (ROS) production and causes oxidative stress. Excess cellular levels of ROS cause damage to proteins, nucleic acids, lipids, membranes and organelles. This damage has been associated with various diseases. These include cancer, hypertension, ischemia/perfusion, cardiovascular diseases, chronic obstructive pulmonary disease, diabetes, insulin resistance, acute respiratory distress syndrome, idiopathic pulmonary fibrosis, asthma, skin diseases, chronic kidney disease, eye diseases, neurodegenerative diseases (amyotrophic lateral sclerosis, Parkinson’s disease, Alzheimer’s disease, and Huntington disease). Natural antioxidants are popular drugs that are used by the majority of people and have few side effects. Natural antioxidants play an important role in reducing free radicals caused by Cd toxicity. Our goal in this review is to establish the relationship between Cd and oxidative stress and to discuss the role of natural antioxidants in reducing Cd toxicity.
Citation - WoS: 10
Citation - Scopus: 10
A study for hydrogen evolution on Pt–MnCu electrocatalyst
(Elsevier, 2023) Yıldız, Reşit; Arslanhan, Selim; Döner, Ali
Electrocatalysts to be used in electrolysis, which is one of the hydrogen production methods, are very important. The development of electrocatalysts is related to the internal structure of combinated more than one metal. In the present work, the graphite substrate is coated with manganez (C/Mn), manganez-copper (C/MnCu) and this surface is modified with platinum nanoparticles (C/MnCu–Pt) using the electrodeposition method. Prepared electrocatalysts are used for characterization, hydrogen evolution reaction (HER) and stability using cyclic voltammetry (CV), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), cathodic current-potential curves, electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA). Hydrogen gas is measured in a basic environment by establishing an experimental electrolysis setup on these electrocatalysts. Results showed that binary MnCu enhances the characteristic current density of Tafel curves, reduces the polarization resistance and enhances the hydrogen gas volume compared to graphite substrate and single Mn coating. Apart from that, much more effective results are obtained on the C/MnCu–Pt electrocatalyst. Namely, a very high exchange current density (io = 5.50 mA cm−2), a very low polarization resistance (3.2 Ω cm2) and a very low overpotential (50 mV) at 10 mA cm−2 are obtained on the C/MnCu–Pt electrocatalyst. In addition to high performance, C/MnCu–Pt electrocatalyst exhibits good stability in alkaline medium.
Citation - WoS: 208
Citation - Scopus: 254
Toxicity of carbon tetrachloride, free radicals and role of antioxidants
(De Gruyter, 2020) Unsal, Velid; Çiçek, Mustafa; Sabancılar, İlhan
Several chemicals, including environmental toxicants and clinically useful drugs, cause severe cellular damage to different organs of our body through metabolic activation to highly reactive substances such as free radicals. Carbon tetrachloride is an organic compound of which chemical formula is CCl₄. CCl4 is strong toxic in the kidney, testicle, brain, heart, lung, other tissues, and particularly in the liver. CCl4 is a powerful hepatoxic, nephrotoxic and prooxidant agent which is widely used to induce hepatotoxicity in experimental animals and to create hepatocellular carcinoma, hepatic fibrosis/cirrhosis and liver injury, chemical hepatitis model, renal failure model, and nephrotoxicity model in recent years. The damage-causing mechanism of CCl4 in tissues can be explained as oxidative damage caused by lipid peroxidation which starts after the conversion of CCl4 to free radicals of highly toxic trichloromethyl radicals (•CCl₃) and trichloromethyl peroxyl radical (•CCl₃O2) via cytochrome P450 enzyme. Complete disruption of lipids (i.e., peroxidation) is the hallmark of oxidative damage. Free radicals are structures that contain one or more unpaired electrons in atomic or molecular orbitals. These toxic free radicals induce a chain reaction and lipid peroxidation in membrane-like structures rich in phospholipids, such as mitochondria and endoplasmic reticulum. CCl4-induced lipid peroxidation is the cause of oxidative stress, mitochondrial stress, endoplasmic reticulum stress. Free radicals trigger many biological processes, such as apoptosis, necrosis, ferroptosis and autophagy. Recent researches state that the way to reduce or eliminate these CCl4-induced negative effects is the antioxidants originated from natural sources. For normal physiological function, there must be a balance between free radicals and antioxidants. If this balance is in favor of free radicals, various pathological conditions occur. Free radicals play a role in various pathological conditions including Pulmonary disease, ischemia / reperfusion rheumatological diseases, autoimmune disorders, cardiovascular diseases, cancer, kidney diseases, hypertension, eye diseases, neurological disorders, diabetes and aging. Free radicals are antagonized by antioxidants and quenched. Antioxidants do not only remove free radicals, but they also have anti-inflammatory, anti-allergic, antithrombotic, antiviral, and anti-carcinogenic activities. Antioxidants contain high phenol compounds and antioxidants have relatively low side effects compared to synthetic drugs. The antioxidants investigated in CCI4 toxicity are usually antioxidants from plants and are promising because of their rich resources and low side effects. Data were investigated using PubMed, EBSCO, Embase, Web of Science, DOAJ, Scopus and Google Scholar, Carbon tetrachloride, carbon tetrachloride-induced toxicity, oxidative stress, and free radical keywords. This study aims to enlighten the damage-causing mechanism created by free radicals which are produced by CCl4 on tissues/cells and to discuss the role of antioxidants in the prevention of tissue/cell damage. In the future, Antioxidants can be used as a therapeutic strategy to strengthen effective treatment against substances with high toxicity such as CCl4 and increase the antioxidant capacity of cells.

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