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Öğe Determination of hydroxymethylfurfural in Turkish honeys, pekmez (grape molasses), and jam samples by high-performance liquid chromatography with diode array detection(Wiley, 2022) Elmastaş, Ayhan; Aydın, Fırat; Umaz, Adil; Kılınç, Ersin; Arslan, Yasin; Aydın, IşılHydroxymethylfurfural (HMF) is a chemical contaminant that is not naturally present in carbohydrate-containing food samples. The HMF amounts were changed between 4.8 and 214.1 mg/kg in honey; between 7.8 and 204.0 mg/kg in pekmez (grape molasses); between 5.9 and 22.4 mg/kg in strawberry jam; between 6.0 and 65.4 mg/kg in apricot jam; and between 9.2 and 55.9 mg/kg in cherry found by HPLC. The linear calibration plot of HMF was ranged from 0.05 to 10.0 mu g/ml. The correlation coefficient was found to be 0.99997. LOD and LOQ values were found to be 12.0 and 40.0 ng/ml, respectively. According to the experimental results, HMF amounts of four honey samples, three pekmez (grape molasses) samples, one apricot jam, and one cherry jam for investigated samples were found to be higher than the permission amount of Turkish Food Codex. Novelty impact statement Based on experimental results in this study, if the honey is in a transparent package such as a glass, it should be stored in a dark environment. It would be healthier to prefer molasses produced by reliable brands at low temperatures under vacuum instead of molasses made with traditional methods in open boilers. Generally, since jams with high HMF amount have an overcooked or even burnt flavor, this is an extremely negative situation for consumers.Öğe Diyarbakır'da satışa sunulan bazı gıda ürünlerinde hidroksimetilfurfural miktarının HPLC ile tayini(2015) Elmastaş, AyhanBu çalışmada, gıdaların işlenmesi ve depolanması sırasında oluşan Hidroksimetilfurfural (HMF) miktar tayini araştırılmış, sonuçlar Türk Gıda Kodeksi ve TSE standartlarına göre değerlendirilmiştir. Çalışma kapsamında 10 farklı gıda grubunda (bal, pekmez, çilek reçeli, kayısı reçeli, vişne reçeli, elma suyu, kayısı nektarı, portakal nektarı, şeftali nektarı, vişne nektarı ) HMF analizi yapılmıştır. Belirlenen gıda örneklerinde HMF analizleri yüksek basınçlı sıvı kromatografisi (HPLC-DAD) kullanılarak gerçekleştirilmiştir. Çalışma kapsamında incelenen gıda örneklerinde HMF miktarları: Örnekler HMF miktarı Bal 0-214.06 mg/kg Pekmez 7.82 -204.00 mg/kg Çilek reçeli 5.92-22.41 mg/kg Kayısı reçeli 6.00-65.41 mg/kg Vişne reçeli 9.18-55.87 mg/kg Elma Suyu 1.01-2.70 mg/L Kayısı Nektarı 0-8.70 mg/L Portakal Nektarı 0-6.62 mg/L Şeftali Nektarı 1.04-5.51 mg/L Vişne Nektarı 0-5.63 mg/L Anahtar Kelimeler: Hidroksimetilfurfural (HMF),(HPLC-DAD)Öğe An investigation and comparison of concentration change in simulated body fluid medium conditions of the calcium element in 27 different salvia species(Istanbul University, 2023) Umaz, Adil; Aydın, Fırat; Fırat, Mehmet; Yener, İsmail; Ertaş, Abdülselam; Elmastaş, AyhanBackground and Aims: In this study, calcium (Ca) element concentration changes of Salvia species in simulated body fluid (SBF) medium conditions were investigated and the results in these medium conditions were compared with each other. Methods: Salvia species samples were air-dried and ground into powder. Salvia species was prepared as a herbal tea. Prepared teas were left in three different SBF medium conditions. The samples were analyzed using Flame Atomic Absorption Spectroscopy (FAAS) method to determine the Ca absorptions. Also, a correlation analysis of the results obtained in three different SBF medium conditions and the species in simulated gastric fluid (SGF) medium conditions was performed. Results: When the SBF medium conditions were compared, it was determined that the highest Ca absorption of all Salvia species occurred in the SGF conditions. Thus, it can be said that the Ca in plants and foods occurs in the gastric fluid medium and its absorption occurs there. When the result of the correlation analysis was evaluated, it was determined that there was a stronger correlation between the SGF and simulated intestinal fluid (SIF) mediums compared to other mediums. Conclusion: The Ca absorption was determined according to what remained in the SGF the most. Based on the results obtained from SBF medium conditions, it can be said which element is taken in which body fluid medium. Information on the differences between samples belonging to different SBF medium conditions was not obtained. However, when the simulated fluid medium conditions were evaluated individually, information was obtained for two or more samples.Öğe Investigation of changes against time in the artificial gastric liquid medium of pesticide active substances(Iğdır Üniversitesi Fen Bilimleri Enstitüsü, 2021) Elmastaş, Ayhan; Umaz, Adil; Aydın, FıratIn this study, grown tomato samples were examined changes of pesticide active substances by two different methods in the artificial gastric liquid (AGL) medium prepared. In the first method, Trifloxystrobin and Imidacloprid pesticide active substances were sprayed on the tomato samples before the harvest period. Time-dependent change of the active substance of Trifloxystrobin; although initially 83.17 ng g-1, it was determined as 24.71 ng g-1 in 240 min. The concentration of this active substance was determined that decreased with time and the % change was 70.29. While Imidacloprid active substance initially was 10.20 ng g-1, it was determined as 10.32 ng g-1 at 240 min. It was determined that this active substance did not change between the first and the last concentration depending on the time. In the second method, 75 pesticide active substances were spiked to the tomato sample and the time-dependent change in the AGL medium was examined. The concentration of 10 active substances that above 70% of the change rate was determined that there was a statistical decrease depending on the time % changes in the range between 0-240 min. The concentration of 30 active substances in below 70% of the change rate was determined that did not a statistical decrease as depending on time. however, % changes were observed that there was a certain thought at different rates between the first and the last concentration after 240 min. The last 15 active substances 240 min concentrations were determined that increased of % changes compared to 0 min.Öğe Quantitative determination and removal of pesticide residues in fresh vegetables and fruit products by LC–MS/ MS and GC–MS/MS(Springer Science and Business Media, 2023) Elmastaş, Ayhan; Umaz, Adil; Pirinç, Vedat; Aydın, FıratPesticides are the potent agrochemicals used to successfully manage, repel, or stop pests and weeds in agricultural production. This study analyzed 222 pesticide active substances in 90 samples of seven different vegetables and fruits acquired from producers through liquid chromatography-mass spectrometry/mass spectrometry (LC–MS/MS) and gas chromatography-mass spectrometry/mass spectrometry (GC–MS/MS) technology. The validation parameters of each pesticide’s active substances were determined. The LOD, LOQ values, and recovery studies of the 222 active substances were 3.00, 10.00 ng/g, and between 76.07 and 108.08%, respectively. The correlation coefficients and measurement uncertainty were determined to be between 0.990–0.999 and 8.91– 31.46%, respectively. There were active substances of chlorpyrifos, acetamiprid, azoxystrobin, difenoconazole, malathion, dieldrin, boscalid, triticonazole, tebuconazole, triadimenol, trifloxystrobin, pirimicarb, and dodine among the vegetable and fruit samples used in the study. There were no active substances in 55 (61%) samples. Among the 35 samples (39%), 31 samples (34%) contained only one active substance, whereas four (5%) contained two active substances. However, the amount of active substances in six (7%) samples was above the maximum residue levels (MRL) limits. Various processes used in the study revealed that peeling was the most effective pesticide residue removal strategy. The washing procedure also proved that it reduced some pesticide residues but failed to eliminate all pesticides. The peeling process successfully reduced a significant amount of the active substances from the products, however, residues remained. Washing the fruits with hot water was also effective in removing residues. As a result, analyses of the peeled sections yielded higher pesticide residue concentrations than those of the entire product.Öğe Yaş meyve sebze ürünlerinin çeşitli koşullarda pestisit kalıntılarının LC-MS/MS ve GC-MS/MS ile analizlerinin kantitatif tayini(Dicle Üniversitesi, Fen Bilimleri Enstitüsü, 2018) Elmastaş, Ayhan; Aydın, Fırat; Bakırdere, SezginBu çalışma, yaş meyve sebze ürünlerin çeşitli koşullarda pestisit kalıntılarının kantitatif analizlerini kapsamaktadır. Tez dört kısımdan oluşmaktadır. Birinci kısımda Dicle Üniversitesi Ziraat Fakültesi bahçe bitkileri bölümü uygulama alanında domates, hıyar, patlıcan sebzeleri yetiştirilmiş ve hasattan önce ilaç uygulamaları yapılıp etki süresi içinde etken maddelerin kantitatif olarak tayinleri yapılmıştır. İkinci kısımda üreticiden toplanan 7 farklı meyve, sebze (domates, hıyar, patlıcan, biber, üzüm, elma, kayısı) örneklerinde, LC-MS/MS ile 173, GC-MS/MS ile 50 olmak üzere toplamda 223 etken maddesinin analizi yapılmıştır. Ürünlerin kalıntı taşıyıp taşımadığıincelemiştir. Bulunan sonuçlar pestisit kalıntı yönetmenliğine göre değerlendirilmiştir. Üçüncü kısım da, pestisit kalıntısı taşıyan örnekler için pestisit kalıntılarının azaltılmasına yönelik bazı prosesler uygulanmış ve analizleri yapılmıştır. Dördüncü ve son kısımda yapay mide ortamında pestisit etken maddelerin davranışları zamana bağlı olarak incelenmiş ve kantitatif analizleri yapılmıştır. Çalışma kapsamında belirlenen meyve sebze örneklerinde pestisit kalıntı analizleri, GCMS/MS ve LC-MS/MS cihazları ile yapılmıştır. Bu cihazlarda optimizasyon çalışmaları yapılmış ve analiz validasyon parametreleri çalışılarak analiz geçerli kılınmıştır. 223 etken maddesinin LOQ değerleri 0,010 mg/kg, geri kazanım çalışmaları %70-120 arası tespit edilmiştir. Çalışma kapsamında meyve sebze örneklerinde incelenen ve tespit edilen pestisit kalıntı etken maddeleri: Domateste;Acetamiprid, Azoxystrobin, Chlorpyrifos, Difencanozale Imidacloprid, Trifloxystrobin, Hıyar'da; Acetamiprid, Chlorpyrifos, Dieldrin, Imidacloprid, Malathion, Trifloxystrobin, Biber'de ; Acetamiprid, Azoxystrobin, Chlorpyrifos,Patlıcan'da; Acetamiprid, Imidacloprid, Trifloxystrobin, Üzüm'de;Azoxystrobin, Boscalid, Difenconazole, Tebuconazole, Tridiamneol, Trifloxstrobin, Triticanozole, Kayısı'da; Malathıon, Tebucanozole, Primicarb, Dodine, Acetamiprid, tespit edilmiştir. Yapay mide ile yapılan çalışmada, pestisit etken maddelerin farklı kimyasal özelliklerine göre yapay mide ortamında farklı oranda değiştiği tespit edildi.
