Nihat Özcan

Prof. Nihat Özcan

orcid

Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

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

Representative Publications

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30 September 2017 in Food Analytical Methods
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NÖNihat Özcan
Nihat Özcan
SBSoyhan Bagci
Soyhan Bagci

1 September 2013 in Journal of AOAC INTERNATIONAL
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NÖNihat Özcan
Nihat Özcan
OAOzlem Aycan
Ozlem Aycan
This study describes determination of chloramphenicol (CAP) in honey, milk, and egg by LC-electrospray ionization (ESI)-MS. CAP was extracted with ethyl acetate from honey, and with acetonitrile from milk and egg. d5-CAP was used as the internal standard. Separation was achieved on a ZORBAX Eclipse C18 2.1 id, 150 mm, 2.1 μm column. The mass spectrometer was equipped with an ESI interface in negative mode. Mass determination of CAP and d5-CAP was carried out in selected ion monitoring mode by scanning m/z 321 for CAP and m/z 326 for d5-CAP as quantification ions, and m/z 323 as the confirmation ion. The validation of the analytical method was performed by carrying out linearity, LOD, LOQ, accuracy, precision, and recovery. Calibration curve was linear between 0.1 and 20.0 ng/g with correlation coefficient >0.998. Accuracy of the method for the honey sample was 95%, and for the milk powder sample 106%. Precision of the method, expressed as CV%, varied between 1.60 and 4.37 for intraday and 2.00 to 5.67 for interday. Quantification limits of method were 0.05, 0.08, and 0.09 ng/g for egg, milk, and honey, respectively. Recovery of the method ranged between 86 and 103% for all three matrixes and two different concentrations. Finally, the method was checked by participating proficiency tests from the Food Analysis Performance and Assessment Scheme 0281 and 0298 honey samples. Z scores were –1.0 and 0.4, respectively.

13 October 2023 in Food Science & Nutrition
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FÖFahriye Şeyma ÖZCAN
Fahriye Şeyma ÖZCAN
HDHilal Dikmen
Hilal Dikmen
NÖNihat Özcan
Nihat Özcan
ÖÇÖzlem Çetin
Özlem Çetin
MÇMustafa Çelik
Mustafa Çelik
Antoaneta TrendafilovaAntoaneta Trendafilova
Antoaneta Trendafilova
Inula helenium roots are consumed as natural flavor components and raw or cooked as food, and their extracts are rich in sesquiterpene lactones such as alantolactone (AL) and isoalantolactone (IAL), which have recently attracted great attention due to their pharmacological properties. The industrial utilization of these compounds requires the development of green, efficient, cost‐effective, and sustainable extraction protocols. Therefore, this study focused on the optimization of microwave‐assisted extraction (MAE) process variables using Face‐Centered Central Composite Design (FC‐CCD). Then, maceration was applied as a conventional technique, and these techniques were compared in terms of extraction efficiency, morphological changes, antimicrobial activities, carbon emissions, and energy consumption. As a result, optimal MAE conditions, i.e., EtOH: water ratio (X1) = 100:0, liquid/sample ratio (X2) = 30:1 mL/g, microwave power (X3) = 300 W, and irradiation time (X4) = 5 min, were obtained with AL and IAL yields of 54.99 ± 0.11 (mg/g) and 48.40 ± 0.19 (mg/g), respectively. The extract obtained by MAE had similar or better activity than positive controls in most cases and formed the largest inhibition zones against E. coli (29.5 ± 0.71 mm) and A. niger (34.75 ± 1.06 mm). Morphological changes of I. helenium roots after extraction were observed by scanning electron microscopy. Additionally, MAE was 43.4 times faster than maceration, resulting in 228.6 times less energy consumption and carbon emissions. Based on these findings, it is recommended to use MAE as an industrial green technique for the extraction of sesquiterpene lactones with potential applications in nutraceuticals and food products in terms of sustainable economy and environmental protection.

20 March 2024 in Food and Bioprocess Technology
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FÖFahriye Şeyma ÖZCAN
Fahriye Şeyma ÖZCAN
NÖNihat Özcan
Nihat Özcan
HMHilal Dikmen Meral
Hilal Dikmen Meral
ÖÇÖzlem Çetin
Özlem Çetin
MÇMustafa Çelik
Mustafa Çelik
Antoaneta TrendafilovaAntoaneta Trendafilova
Antoaneta Trendafilova
The sesquiterpene lactones (SL) of Inula helenium (I. helenium) roots were extracted using high-pressure homogenization (HPH) and compared against those derived from maceration. The effect of process conditions on the extraction efficiency of bioactive compounds (alantolactone, isoalantolactone, total phenols, and flavonoids); the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity, ferric-reducing antioxidant power (FRAP), and antimicrobial activity of the extract; and the inhibition of advanced glycated end product (AGE) formation were assessed. The HPH of 90 MPa for 4 passes demonstrated the highest alantolactone (38.1 ± 0.7 mg/g) and isoalantolactone yields (34.4 ± 0.2 mg/g), respectively, which were significantly higher than the rates obtained using maceration (20.0 ± 0.2 mg/g and 18.9 ± 0.7 mg/g). Under optimal extraction conditions of 90 MPa for 4 passes, inhibition of AGE formation in the extract reached a rate of 97.16 ± 1.86%, with the highest DPPH and FRAP of 231.63 ± 2.96 µg/mL and 949.43 ± 1.86 µmol TE/100 mL, respectively. HPH exhibited lethal activity against all tested bacteria and fungi strains (Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Aspergillus niger, Fusarium oxysporum, and Penicillum expansum) at a concentration of 15 µL. SEM results proved that HPH severely damaged the cell structures of roots, increased solvent permeability, and improved the extraction rate of bioactive compounds. Additionally, this study also demonstrated that HPH yields high recovery with a specific energy consumption of 0.22 kWh/kg, which is close to the recommended minimum energy demand for an extraction procedure within industrial production processes. Therefore, these findings showed that HPH can be used as an efficient extraction technique for the production of SL in related industries.

7 February 2020 in TURKISH JOURNAL OF AGRICULTURE AND FORESTRY
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FÖFahriye Şeyma ÖZCAN
Fahriye Şeyma ÖZCAN
NÖNihat Özcan
Nihat Özcan
AUAhmet Abdullah Us
Ahmet Abdullah Us
Osman SagdicOsman Sagdic
Osman Sagdic

16 March 2019 in International Journal of Environmental Analytical Chemistry
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NÖNihat Özcan
Nihat Özcan
SASüleyman Akman
Süleyman Akman
Amitraz is a non-systemic acaracide and insecticide. Current maximum residue limits for amitraz are stated as ‘Amitraz including the metabolites containing the 2,4-dimethylaniline moiety’. Therefore, determination of amitraz and its all degradation products are important. In this study, we develop a gas chromatography/mass spectrometry (GC/MS) method for determination of amitraz and its degradation products 2,4 dimethylaniline (DMA), 2,4 dimethylformamidine (DMF) and N-(2,4-dimethyl phenyl)-N’-methylformamidine (DMPF) in cucumber and quince. The mechanism of the degradation process was monitored at different temperatures. Amitraz and its degradation products were extracted using the QuEChERS method. To determine amitraz and its degradation products, we used GC/MS. Quantification was carried out by using selected ion monitoring, and total ion chromatogram was used to monitor additional degradation products. The method was validated by studying linearity, limit of detection (LOD) and limit of quantification (LOQ), recovery and precision. The mechanism of the degradation process was monitored at different temperatures. Degradation of amitraz mainly to three degradation products, namely DMA, DMF and DMPF, increased with temperature. Besides these three main degradation products, two other new degradation products were detected.