Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(11)
- Mercan, Emin(10)
- Ustabulut, Mete Yusuf(10)
- Ayata, Ümit(9)
- Kaya, Yunus(9)
- Sert, Durmuş(9)
- Ertugrul, Mehmet(8)
- Hasar, Ugur Cem(6)
- Tozlu, Alperen(6)
- Öner, Erdal(6)
- Abdioglu, Murat(5)
- Aktaş, Esat(5)
- Arslaner, Ayla(5)
- Bayram, Ozkan(5)
- Bulut, Mehmet(5)
- Ecem Bayram, Nesrin(5)
- Gürleyen, Levent(5)
- Karaduman, Ruken(5)
- Kaya, Feridun(5)
- Kul, Sinan(5)
- Türkmen, Mutlu(5)
- İspirli, Hümeyra(5)
- Artar, Musa(4)
- Arı, Ari(4)
- Azili, Kenan(4)
- Azimkhani, Amin(4)
- Bayraktar, Bülent(4)
- Dayı, Özkan(4)
- Gül, Volkan(4)
- Izginli, Mucahit(4)
- Kaban, Abdullatif(4)
- Kalay, Erbay(4)
- Kuzey, Memet(4)
- Ozdemir, Gazi(4)
- Ozturk, Gokhan(4)
- Ozturk, Hamdullah(4)
- Ozturk, Kemal(4)
- Saatchian, Vahid(4)
- Sarikaya, İsmail(4)
- Tekce, Emre(4)
Yayınlar
- MakaleAçık Erişim2021Scopus SJRQ4Secure internet use in information technologies and software course textbooks at primary and secondary schools
Kaban, Abdullatif
Do we care about the security on the internet environment the way we do in the daily life safety of our children? In order to answer this question, this study aims to reveal what kind of education is provided at school about using secure internet. In accordance with this purpose, Information Technologies and Software Course textbooks at primary and secondary schools are examined applying document analysis method and analyzed by content analysis method. According to the findings, in the textbooks, the most frequently mentioned topics related to the use of secure internet are “protection of personal data”, “security measures that can be taken” and “digital footprint”; and the most frequently mentioned topics related to the ethic are “internet ethics” and “respect for others”. In this study on the use of secure internet, suggestions have been made about the precautions to be taken. The results are expected to provide information and resources to the researchers who work on secure internet use, educational institutions and teachers.
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İncele - MakaleAçık Erişim2021Scopus SJRQ3An analysis of the role of the social acceptance of university students’ bicycle use in sustainable urban development when epidemics spread
Saatchian, Vahid; Azimkhani, Amin; Honari, Habib; Türkmen, Mutlu
The purpose of this study was to investigate the role of the acceptance of university students’ bicycle use in sustainable urban development in Iran when epidemics spread. The research method was descriptive-correlational, and the investigation was carried out as a field study. The statistical population of the study consisted of university students, 254 of whom were selected by a simple random sampling method to participate in the research. The research instrument was a questionnaire based on the Sustainable Development with a reliability coefficient of 0.83; the social acceptance component was based on the theory of planned behaviour with a reliability coefficient of 0.8. As the results of the investigation have demonstrated, the bicycle plays a significant role in the development of the socialization process of people, and there is a positive and significant relationship between social acceptance and sustainable development (p<0.05). Furthermore, 20% of sustainable development change was achieved through the dimensions of social acceptance (planned behaviour theory). Finally, it can be argued that perceived behaviour in social acceptance is most likely to play a significant role in the emergence of sustainable development by external factors such as encouragements and persuasion of the family, important people, friends, acquaintances, and even by the existing norms in society. Subsequently, as people change their mindset when epidemics spread, they can turn all the behaviours they manifest in their leisure time into a culture development movement.
AtıfScopus2OpenAlex2İncele - MakaleYalnız künye2021Scopus SJRQ1Learning trajectory of a student with learning disabilities for the concept of length: A teaching experiment
Güven Akdeniz, Dilşad; Argün, Ziya
This study aims to map the learning trajectory (LT) of a student with learning disabilities (LDs) regarding the unit concept in length measurement and the usage of rulers. The article draws on data from a teaching experiment with a 10-year-old student with LDs in Turkey. Data were analyzed in two stages, including microanalysis, where each successive teaching session was separately analyzed, and macroanalysis, where the teaching sessions regarding interrelated instructional goals were analyzed to construct the LT. The main findings of the study illustrate that this student with LDs eliminated her misconceptions about the unit concept and using a ruler, accomplished the determined instructional goals to a large extent, and reached a higher level of thinking with a 4-month teaching experiment designed based on her specific developmental capacity.
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İncele - MakaleYalnız künye2021Scopus SJRQ1Assessment of different solution methods for receding contact problems in functionally graded layered mediums
Yaylacı, Murat; Eyüboğlu, Ayşegül; Adıyaman, Gökhan; Yaylacı, Ecren Uzun; Öner, Erdal; Birinci, Ahmet
This paper presents a comparative study of different methods, such as the analytical method, finite element method (FEM), and multilayer perceptron (MLP) for analyzing a frictionless receding contact problem. The problem consists of two layers resting on a Winkler foundation. The top layer is functionally graded (FG) along the depth and pressed using a rigid cylindrical stamp, whereas the bottom layer is homogeneous. We assumed that the contact between the two layers, and that between the FG layer and the rigid cylindrical stamp are frictionless; additionally, compressive normal tractions can be transmitted through the interface. First, the problem was solved analytically using the theory of elasticity and integral transform techniques. Second, the finite element solution of the problem was obtained using ANSYS software. Finally, the problem was extended based on the MLP, which an artificial neural network used for different problem parameters. The results of this study showed that the variations in the contact lengths at the interface between the rigid cylindrical stamp and the FG layer, those between the homogeneous layer and the FG layer, and the maximum contact pressures at these interfaces depended on various dimensionless quantities such as the stamp radius, stiffness parameter, shear modulus ratio, and elastic spring constant ratio. We observed that the results obtained with the three different methods, namely the analytical method, FEM, and MLP, are extremely compatible with each other, thus proving the accuracy of these results.
AtıfScopus87WoS86OpenAlex40İncele - MakaleAçık Erişim2021Scopus SJRQ2A surveying of photon and particle radiation interaction characteristics of some perovskite materials
Şakar, Erdem; Alim, Bünyamin; Fırat Özpolat, Özgür; Ceviz Şakar, Betül; Baltakesmez, Ali; Akbaba, Uğur
In this study, we aimed to determinate of the photon and particle radiation interaction parameters of six different perovskites to help use perovskite materials in radiation applications. The parameters that are aimed to be investigated are MAC, HVL, MFP, Zeff, Neff, Ceff and EBF for photons, range values for charged particles, and FNRCS values for neutrons. The photon-interaction parameters the FNRCS values of the perovskites were calculated using Phy-X/PSD software in the energy range of 1 keV–100 GeV for photons and at 4.5 MeV energy for neutrons, respectively. Moreover, the range values of the perovskites were calculated using SRIM Monte Carlo software (for H+ and He++ particles) and ESTAR NIST software (for electrons) in the energy range from 0.01 MeV to 20 MeV. In order to make a notable assessment about the radiation interaction possibilities of the perovskites, the results obtained were compared with some standard shielding materials. According to the results obtained for all radiation types examined, it was determined that all calculated parameters were strongly dependent on both the type and energy of the radiation and the type of material. Additionally, it was observed that the order of preference of the examined materials as armor material in radiation applications varies according to the radiation type and energy. Consequently, it was determined that while the most suitable material in terms of photon shielding is P6 (Cs2SnI6) inorganic perovskite among the perovskites examined, this sample is not suitable material for neutron shielding applications.
AtıfScopus27WoS25OpenAlex26İncele - MakaleYalnız künye2021Scopus SJRQ1Students’ Well-Being and Academic Achievement: A Meta-Analysis Study
Kaya, Metin; Erdem, Cahit
A considerable amount of literature has been published on students’ well-being, but empirical research has yielded ambiguous results regarding the relationship between well-being and academic achievement. Meta-analysis studies on this issue are scarce, and the available studies focus on a single domain of well-being. Meta-analyses investigating students’ general well-being and academic achievement are needed. To this end, we carried out a meta-analysis study on the association between students’ general well-being and academic achievement based on data from correlational studies involving 54,426 participants in 81 independent samples. We report a significant and positive but small effect size based on this dataset. The effect sizes differ significantly in terms of the moderator variables of publication year, age, school level, and publication type, while the correlation is robust across well-being domains, academic areas, scale types, and development levels of countries. Results are discussed and implications are suggested in line with the literature.
AtıfScopus200WoS158OpenAlex225İncele - MakaleAçık Erişim2021Scopus SJRQ1Synthesis and characterization of cellobiose-derived oligosaccharides with Bifidogenic activity by glucansucrase E81
İspirli, Hümeyra; Bowman, Michael J.; Skory, Christopher D.; Dertli, Enes
Cellobiose-derived oligosaccharides were produced from acceptor reactions with glucansucrase E81 and their prebiotic potentials were determined in this study. The major product was a mixture of trisaccharides formed by the addition of an α-linked glucose to cellobiose at either the 2-O position of the reducing end (86%) glucose or the 6-O position of the non-reducing end glucose (11%) demonstrated by NMR spectroscopy and LC-MS-LTQ analysis. The purified DP 3 cellobiose-derived oligosaccharides were then tested for in vitro human gastric juice and α-amylase digestion and no digestion was observed during the 6 h digestion period. Importantly, DP 3 cellobiose-derived oligosaccharides promoted the growth of Bifidobacteria at high levels demonstrating a Bifidogenic effect and a mild level of proliferation was observed for Lactobacilli suggesting the prebiotic roles of cellobiose-derived oligosaccharides.
AtıfScopus7WoS5OpenAlex6İncele - MakaleAçık Erişim2021Scopus SJRQ1Thermoeconomic analysis of a hybrid cogeneration plant with use of near-surface geothermal sources in Turkey
Tozlu, Alperen; Gençaslan, Betül; Özcan, Hasan
In this study, thermodynamic and thermoeconomic analyses of systems that produce electricity and heat through the use and storage of solar energy and near-surface geothermal sources are carried out. Three different configurations, which are the organic Rankine cycle (ORC), cogeneration system (CGN) and hybrid system (HYB), are coupled to the parabolic trough collector (PTC) system. The systems are named PTC-ORC, PTC-CGN and PTC-HYB are conducted. The reference system called PTC-ORC only produces electrical energy with parabolic trough collectors and it does not have a thermal energy storage system, whereas in PTC-CGN, in addition to the cogeneration of electricity and heat, thermal energy storage is also available. Finally, thermodynamic and economic analyses are conducted in the PTC-HYB with the assistance of near-surface geothermal energy, which is widely available in Turkey. In this study, the actual data of Ankara Kızılcahamam near-surface geothermal fields are taken as the heat source for the hybrid system. These facilities, each producing 1 MW of electricity, are first optimized with the help of parametric studies, and exergoeconomic analysis is performed with respect to optimum thermal conditions. The electricity production costs of PTC-ORC, PTC-CGN and PTC-HYB are found to be 0.257 $/kWh, 0.448 $/kWh and 0.401 $/kWh, respectively. The study demonstrates that thermal energy storage brings extra costs, while near-surface geothermal sources may help decrease energy costs from renewables.
AtıfScopus15WoS13OpenAlex21İncele - MakaleAçık Erişim2021Scopus SJRQ3Comparing of the Magnetic Force Parameters of Superconducting Maglev System Using Horizontal and Vertical PMG Geometry in Multi-Surface HTS-PMG Arrangement
Ozturk, Kemal; Savaskan, Burcu; Abdioglu, Murat; Cansiz, Ahmet; Dilek, Durukan Burak; Karaahmet, Zekeriya
In this study, a detailed static and dynamic experimental studies were carried out in different cooling heights (CH) by using two different multi-surface HTS-PMG arrangements with horizontal (MS-H) and vertical (MS-V) geometries to determine the optimum magnetic force, static stiffness, dynamic response, and dynamic stiffness parameters of superconducting Maglev system. The maximum levitation force values (in CH = 25 mm) were obtained as 202 N and 84 N, respectively, with horizontal and vertical geometry HTS-PMG arrangements, while the maximum guidance force values (in CH = 5 mm) were obtained as −58 N and −22 N, respectively. Also, the vertical static (in CH = 25 mm) and dynamic stiffness (in CH = 5 mm) values were determined as 33.8 N/mm and 37.8 N/mm, respectively, for MS-H and 12.3 N/mm and 25.1 N/mm, respectively, for MS-V arrangements. The bigger levitation force, guidance force, and both static and dynamic magnetic stiffness values of MS-H arrangement with horizontal geometry than that of MS-V arrangement with vertical geometry indicate that the horizontal HTS-PMG geometry is more suitable for practical Maglev applications in terms of loading capacity and movement stability.
AtıfScopus5WoS4OpenAlex4İncele - MakaleAçık Erişim2021Scopus SJRQ1New formalism for characterization of simple non-reciprocal networks free from singularity-point problem
Hasar, Ugur Cem; Kaya, Yunus; Ozturk, Gokhan; Ozturk, Hamdullah; Izginli, Mucahit; Ertugrul, Mehmet
A method has been proposed for accurate characterization of non-reciprocal networks without enforcing the passivity principle. Thanks to the introduced different even and odd coefficients, our method has no singularity-point problem as compared with the conventional method. The proposed method is validated by scattering parameter measurements of a ferrite-loaded waveguide shifter. In addition, it is demonstrated by measurements that our method, as compared with the conventional one, is more resistant to random noise due to post-calibration effects.
AtıfScopus1WoS1OpenAlex1İncele - MakaleAçık Erişim2021Scopus SJRQ1A comparative thermoeconomic analysis and optimization of two different combined cycles by utilizing waste heat source of an MSWPP
Ozahi, Emrah; Abusoglu, Aysegul; Tozlu, Alperen
In this paper, thermodynamic and thermoeconomic analysis as well as genetic algorithm optimization of two combined cycles, a gas turbine-organic Rankine cycle (GT-ORC) and a gas turbine-Kalina cycle (GT-KAL) are carried out. The novelty of this study is that the cycles are adapted to an actual solid waste power plant to generate additional power from the exhaust gas. Thus, the power generation capacity of the actual power plant can be raised by using the combined cycle. Due to this reason, besides the thermodynamic analysis of the cycles, thermoeconomic analyses and optimizations are also very important in order to improve the actual system capacity. The net power output of GT-ORC and GT-KAL are found to be 1.51 MW and 1.59 MW, respectively. The results obtained are seen to be reasonable when compared to the net power output of the power plant (5.66 MW). Another originality of this study is that the thermoeconomic results are improved by utilizing a multi-objective optimization method namely non-dominated sorting genetic algorithm method (NSGA-II). Thus, the two objectives, total power output and the total cost rate, at the design stage of the cycles are optimized and enhanced. Due to the optimization results, it is found that the net power output of the GT-ORC and GT-KAL are increased by 11.34% and 0.99%, respectively, while the total cost rates are decreased by 18.59% and 1.31%, respectively. GT-ORC with the net power output of 1.70 MW is seen to be more efficient as compared to GT-KAL which produces a net power output of 1.61 MW. However, the total and the capital cost rates of GT-ORC are found to be higher than those of GT-KAL.
AtıfScopus7WoS5OpenAlex11İncele - Kitap BölümüAçık Erişim2021Parallel Assembly Lines with Heterogeneous Workforce: A Cost-Driven Mathematical Model and Simulated Annealing Approach
Kökhan, Serhan; Baykoç, Ömer Faruk; Xu, J; Marquez, FPG; Hassan, MHA; Duca, G; Hajiyev, A; Altiparmak, F
In recent years it has become possible for people, machines and robots to work collaboratively in most production environments. Collaborative working models, which are diversified with the concept of Industry 4.0, have become an important issue in Assembly Line Problems (ALP). In this study, a cost-driven mathematical model which combines Parallel Assembly Line Problems and human and robot collaborative workforce which is an important parameter of Industry 4.0 philosophy is proposed. The mathematical model was tested for new data sets derived from existing data sets in the parallel assembly lines literature and the results were analyzed. Because of the NP-hardness of ALP, a heuristic approach based Simulated Annealing (SA) algorithm was proposed to solve for larger sized problems. For this purpose, the same data sets were solved with SA and the results were compared and analyzed. The results show that the mathematical model gives better results up to Tonge data set (140 task), but feasible solutions can only be obtained by SA algorithm for the rest. Since there are very few studies with heterogeneous workforce in Parallel Assembly Line Balancing Problems (PALBP), this study is believed to provide a significant contribution to related literature.
AtıfScopus5WoS5OpenAlex8İncele - MakaleAçık Erişim2021Scopus SJRQ4Mathematics teachers’ pedagogical content knowledge involving the relationships between perimeter and area
Yilmaz, Demet Deniz; Demir, Betül Küçük
This study aims to investigate and compare mathematics teachers’ knowledge of pedagogical content, knowledge of students’ understanding and knowledge of instructional strategies, subcomponents of pedagogical content knowledge, student errors in the relationship between perimeter and areas in rectangles, squares, and parallelograms. 10 pre-secondary school in-service mathematics teachers and 10 prospective mathematics teachers participated in the study. The qualitative case research approach was used. To collect the data, an interview form consisting of four questions showing student errors related to perimeter and area was prepared. The participants were asked to comment on the questions given in the form, and their answers were recorded. Later, they were asked to write down their answers to these questions. According to the outcomes, there is a lack of knowledge of students’ understanding and knowledge of instructional strategies, which are the subcomponents of the pedagogical content knowledge of prospective mathematics teachers. Moreover, prospective teachers are found to be incompetent as regards the necessary mathematical subject matter knowledge. To prevent difficulties, when the concepts of perimeter and area are taught, instead of giving formulae initially, concrete materials or real-life examples about these concepts should be provided.
AtıfScopus5OpenAlex5İncele - MakaleAçık Erişim2021Scopus SJRQ4Cognitive and metacognitive skills performed by math teachers in the proving process of number theory
Ozturk, Mesut
Evaluating the proving process of mathematics teachers is important for the development of their proof skills. Developing the proof skills of teachers can contribute to their students’ meaningful learning of mathematics. For example, teachers showing simple proofs about number theory can make it easier for students to understand the concepts of multipliers and factors and the concepts of the greatest common divisor and the least common multiple. Within this context, this study was conducted in order to examine the cognitive and metacognitive skills performed by math teachers in the proving process. The study was conducted as a case study using qualitative research design. A total of 14 teachers participated in the study, six of which were elementary math teachers and eight were secondary math teachers. The data were collected through task-based interviews (think-aloud protocol), documents and observation forms. The collected data were analysed using the content analysis method. The results of the study showed that, based on the operational definition of cognition and metacognitive skills made in this study, elementary math teachers generally used cognitive skills, while secondary mathematics teachers performed metacognitive skills.
AtıfScopus4OpenAlex15İncele - MakaleYalnız künye2021Scopus SJRQ2Differential effects of inhibitors of PTZ-induced kindling on glutamate transporters and enzyme expression
Taspinar, Numan; Hacimuftuoglu, Ahmet; Butuner, Selcuk; Togar, Basak; Arslan, Gokhan; Taghizadehghalehjoughi, Ali; Okkay, Ufuk; Agar, Erdal; Stephens, Robert, Jr.; Turkez, Hasan
Epilepsy is a neurological disorder resulting from abnormal neuronal firing in the brain. Glutamate transporters and the glutamate-glutamine cycle play crucial roles in the development of seizures. In the present study, the correlation of epilepsy with glutamate transporters and enzymes was investigated. Herein, male Wistar rats were randomly allocated into four groups (six animals/group); 35 mg/kg pentylenetetrazole (PTZ) was used to induce a kindling model of epilepsy. Once the kindling model was established, animals were treated for 15 days with either valproic acid (VPA, 350 mg/kg) or ceftriaxone (CEF, 200 mg/kg) in addition to the control group receiving saline. After treatment, electrocorticography (ECoG) was performed to record the electrical activity of the cerebral cortex. The glutamate reuptake time (T-80) was also determined in situ using an in vivo voltammetry. The expression levels of glutamate transporters and enzymes in the M1 and CA3 areas of the brain were determined using a real-time polymerase chain reaction (RT-PCR). ECoG measurements showed that the mean spike number of the PTZ + VPA and PTZ + CEF groups was significantly lower (p < 0.05) than that of the PTZ group. Compared with the PTZ group, VPA or CEF treatment decreased the glutamate reuptake time (T-80). The expression levels of EAAC1, GLT-1, GLAST, glutamine synthetase (GS), and glutaminase were increased in the PTZ group. Treatment with VPA or CEF enhanced the expression levels of GLT-1, GLAST, EAAC1, and GS, whereas the glutaminase expression level was reduced. The current results suggest that VPA or CEF decreases seizure activity by increasing glutamate reuptake by upregulating GLT-1 and GLAST expression, implying a possible mechanism for treating epilepsy. Also, we have suggested a novel mechanism for the antiepileptic activity of VPA via decreasing glutaminase expression levels. To our knowledge, this is the first study to measure the glutamate reuptake time in situ during the seizure (i.e., real-time measurement).
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İncele - MakaleAçık Erişim2021Scopus SJRQ3Development of SiO2 based doped with LiF, Cr2O3, CoO4 and B2O3 glasses for gamma and fast neutron shielding
Aygün, Bunyamin; Sakar, Erdem; Karabulut, Abdulhalik; Alim, Bunyamin; Sayyed, Mohammed, I; Singh, Vishwanath P.; Yorgun, Nergiz Yildiz; Özpolat, Ozgur Firat
In this study, the fast neutron and gamma-ray absorption capacities of the new glasses have been investigated, which are obtained by doping CoO,CdWO4,Bi2O3, Cr2O3, ZnO, LiF,B2O3 and PbO compounds to SiO2 based glasses. GEANT4 and FLUKA Monte Carlo simulation codes have been used in the planning of the samples. The glasses were produced using a well-known melt-quenching technique. The effective neutron removal cross-sections, mean free paths, half-value layer, and transmission numbers of the fabricated glasses have been calculated through both GEANT4 and FLUKA Monte Carlo simulation codes. Experimental neutron absorbed dose measurements have been carried out. It was found that GS4 glass has the best neutron protection capacity among the produced glasses. In addition to neutron shielding properties, the gamma-ray attenuation capacities, were calculated using newly developed Phy-X/PSD software. The gamma-ray shielding properties of GS1 and GS2 are found to be equivalent to Pb-based glass.
AtıfScopus19WoS19OpenAlex16İncele - Derleme MakaleAçık Erişim2021Scopus SJRQ1A review on developments of environmentally friendly geopolymer technology
Krishna, R. S.; Mishra, Jyotirmoy; Zribi, Marwa; Adeniyi, Funmilayo; Saha, Suman; Baklouti, Samir; Shaikh, Faiz Uddin Ahmed; Gökçe, H. S.
This study aims to present an overview of the progress of geopolymer composites with regards to the latest developments on its constituents (binders, activators, and aggregates) and manufacturing techniques. Some ecological, economic, and industrial limitations of the traditional aluminosilicate binders yield to the pursuit of alternative ones over the period. Some of these latest binders e.g. ferrochrome ash, mine tailings, rice husk ash, red mud, have been highlighted in this paper. Current advances on replacement of natural fine and coarse aggregates such as mine tailings (iron ore tailings), recycled/lightweight aggregates for geopolymer preparation have been reviewed from the past literature. The paper also focuses on developments regarding the new class of green alkaline and acidic activators, which is traditionally considered to be the binding agent in the preparation of geopolymer composites. Different geopolymer production methods have been briefly discussed to study their effectiveness in achieving a strong and durable composite. This paper may serve to encourage further experimental research works for achieving more sustainable, cost-effective geopolymer composites with enhanced mechanical properties.
AtıfScopus89WoS77OpenAlex88İncele - MakaleAçık Erişim2021Scopus SJRQ1Coupling analysis between resonating metamaterial slabs using scattering parameters
Hasar, Ugur Cem; Kaya, Yunus; Izginli, Mucahit; Ozturk, Hamdullah; Ertugrul, Mehmet; Ramahi, Omar M.
Metamaterial (MM) slabs in close proximity can couple with one another. This coupling can modify the electromagnetic response of the overall MM structure involving individual MM resonators. The signal flow graph technique along with the ABCD parameters are applied to quantitatively and qualitatively examine this coupling from simulated/measured scattering parameters of cascade connection of closely or largely separated MM slabs. S-parameter measurements of a MM slab constructed by split-ring-resonators were carried out at X-band (8.2-12.4 GHz) to validate our theoretical analysis.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2021Scopus SJRQ1Phenolic and free amino acid profiles of bee bread and bee pollen with the same botanical origin - similarities and differences
Bayram, Nesrin Ecem; Gercek, Yusuf Can; Çelik, Saffet; Mayda, Nazli; Kostic, Aleksandar Z.; Dramicanin, Aleksandra M.; Özkök, Asli
In this study, the chemical profile of bee pollen (BP) and bee bread (BB) samples collected from the same beehive were analyzed by LC-MS/MS (liquid chromatography technique coupled with tandem mass spectrometry), providing the identification of 23 phenolic compounds and 42 free amino acids (FAAs). Rutin was the phenolic compound with the highest rate of occurrence in both BP and BB samples. However, concentrations of protocatechuic acid, 2,5-dihydroxybenzoic acid and kaempferol compounds were significantly higher in BB samples than in BP samples from the same hive probably as result of microbial activity and glycosides degradation. The obtained data revealed that the phenolic profiles of the samples differ not only by the type of a product but also by region. Among FAAs proline was the predominant compound in all the analyzed BP and BB samples followed by L-asparagine (BP samples) and L-aspartic acid (BP and BB samples). A high content of proline can be used as a parameter of sample freshness. Also, Principal Component Analysis (PCA) and Cluster analysis proved the possibility of using phlorizin as a chemotaxonomic marker for Rosaceae (Malus or Prunus genus) pollen presence in BP1 sample. In addition, amino acid profile had higher impact on BP and BB sample differentiation due to lower FAAs content in BB samples probably caused by microbial activity. To the best of our knowledge, this study is the first to compare the individual phenolic compounds and free amino acids of bee pollen and bee bread samples with the same botanical origin (predominantly originated from plants belonging to the following families: Asteraceae, Fabaceae, Plantaginaceae and Rosaceae). (C) 2021 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.
AtıfScopus103WoS92OpenAlex114İncele - MakaleAçık Erişim2021Scopus SJRQ2Turkish royal jelly: amino acid, physicochemical, antioxidant, multi-elemental, antibacterial and fingerprint profiles by analytical techniques combined with chemometrics
Ecem Bayram, Nesrin; Çebi, Nur; Çelik, Saffet; Gerçek, Yusuf Can; Bayram, Sinan; Tanugur Samanci, Asli Elif; Sagdiç, Osman; Özkök, Asli
Royal jelly is one of the most remarkable commercial bee products used in cosmetics, medicine, and as a dietary supplement. This study aimed to determine some quality parameters (amino acid, multi-elemental, total phenolic-flavonoid, 10-HDA, sugar, and moisture content) as well as antioxidant and antimicrobial activities of different royal jelly samples (domestic and non-domestic samples). In this study, royal jelly samples exhibited high antioxidant and antimicrobial activity. 10-HDA values were found to be higher in domestic royal jelly samples (2.17-2.71%) compared to non-domestic samples (0.31-1.71%). Also, it was found that the acidity value varied between 2.57-3.37 mL 0.1 N NaOH/g and 3.87-4.97 mL 0.1 N NaOH/g in non-domestic and domestic royal jelly samples, respectively. L-Proline was the amino acid with the highest rate of occurrence in both domestic (21972.39-35053.00 nmol/g) and non-domestic (19688.31-21711.50 nmol/g) samples. It was determined that the new method developed for amino acid analysis has many advantages over other methods. Chemometrics of principal component analysis (PCA) showed that amino acid profile, elemental profile, and chemical parameters were capable of presenting characteristic and descriptive properties of royal jelly samples. In addition to these findings, Raman spectroscopy combined with chemometrics of hierarchical cluster analysis (HCA) was successfully used to distinguish domestic and non-domestic royal jelly samples. The obtained results will provide an important basis for subsequent research on the evaluation of the amino acid content, physicochemical properties, phenolic content, and the antioxidant and elemental profile of royal jelly.
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