Grape is one of the most common crop plants in the world, and Turkey is seventh in fresh grape production. The seedless Sultani grape (Vitis vinifera L.) produced in Manisa is famous worldwide. The determination of antioxidant properties and phenolic substance levels, as well as investigation of the effects of different drying processes on these levels in grapes, is important in terms of revealing their contribution to health. Additionally, determining the levels of pesticide residues in fruit is another important issue for health. Therefore, the aim of this study was to determine the levels of pesticide residues and antioxidant substances in fresh grapes and to evaluate the benefits and harm to health and the effect of drying methods on total antioxidant capacity (TAC), total phenolic content (TPC), and total flavonoid content (TFC). The TAC, TPC, and TFC values of fresh grapes were found to be 12.56 ± 2.33 mg AE/g dry weight (DW), 2.85 ± 1.10 mg GAE/g DW, and 2.51 ± 1.27 mg QE/g DW, respectively. At least one pesticide residue was detected in all samples; iprodione and lambda-cyhalothrin were detected in 82.35% of samples. However, pesticide residues were found to be below the maximum residue levels specified in the Turkish Food Codex. Losses in TAC, TPC, and TFC of the Sultani grapes were found to be 47.45%, 55.02%, and 81.05% and 80.00%, 72.91%, and 72.11% for oven-dried and sun-dried grapes, respectively, in our study. The sundrying method leads to less loss in TPC and TFC values; in terms of TAC value, the best drying method is the oven-drying method. The antioxidant properties of fresh grapes investigated in our study were slightly higher compared to other white grapes in the literature, and there was no significant health risk with respect to pesticides determined in our study.

In this study; glucose oxidase (GOD) and MnO2 were immobilized in alginate gel beads using the entrapment method and effects of oxygen vectors on immobilized GOD activity were investigated. The specific activity of free enzyme was 1.3 units/mg protein whereas that of immobilized enzyme was 8.4 × 10(-1) units/mg protein. The Km values for free and immobilized enzyme were found to be 2.7 mM, 2.9 mM; Vmax values 3.64 × 10(-1) μmol/min.mL, 2.61 × 10(-1) μmol/min.mL, respectively. When 4% (v/v) silicone oil or soybean oil was used, the activity of immobilized GOD increased 1.7 times and 1.3 times, respectively, compared to media without these oils.

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ÖzElma ekşisi Kastamonu yöresine özgü bir yöresel üründür. Kastamonu bölgesinde yetişen lezzetli elmaların (özellikle hürümez elma) kışında içecek ve tatlı olarak değerlendirilmesi amacıyla zahmetle hazırlanan bir gıdadır. Fenolik bileşikler antioksidan özellikleri ile bilinen bileşiklerdir. Buna bağlı olarak antikarsinojen, antimutajen ve antimikrobiyal aktivite göstermeleri bakımından da insan sağlığı üzerine olumlu etkileri vardır. Elma da fenolik bileşikler içeren meyvelerdendir. Bu çalışmada Kastamonu iline özgü elma ekşilerinin toplam fenolik bileşik, toplam flavonoid madde ve toplam antioksidan kapasite tayini yapılmıştır. Elma ekşilerinin en yüksek toplam fenolik bileşik içeriği 3,75 mg gallik asit eşdeğeri/g, en düşük toplam fenolik bileşik içeriği 1,12 mg gallik asit eşdeğeri/g ve ortalama toplam fenolik bileşik içeriği 2,62 mg gallik asit eşdeğeri/g olarak bulunmuştur. En yüksek toplam antioksidan kapasite değeri 11,15 mg askorbik asit eşdeğeri/g, en düşük toplam antioksidan kapasite değeri 6,32 mg askorbik asit eşdeğeri/g ve ortalama toplam antioksidan kapasite değeri 9,46 mg askorbik asit eşdeğeri/g olarak bulunmuştur. En yüksek toplam flavonoid madde içeriği 5,04 mg kuersetin eşdeğeri/g, en düşük toplam flavonoid madde içeriği 2,38 mg kuersetin eşdeğeri/g ve ortalama toplam flavonoid madde içeriği 3,64 mg kuersetin eşdeğeri/g olarak bulunmuştur.Anahtar Kelimeler: Elma Ekşisi; Fenolik; Antioksidan; Flavonoid AbstractApple sour is a local product specific to Kastamonu region. It is a food prepared from tasty apples grown in Kastamonu region (especially hürümez apple) laboriously Gönderim Tarihi 22. 05.2017, Kabul Tarihi: 13.08.2017, Yayım Tarihi: 30.08.2017

5-hydroxymethylfurfural (HMF) is formed by reducing sugars in honey in acidic environments by the Maillard reaction and is known as a carcinogenic, mutagenic and genotoxic compound. The aim of this study is to investigate the toxic HMF content of unbranded flower honey samples sold under the sun under inappropriate conditions and unsupervised on the highway sides and to make an evaluation in terms of food safety. The quality of the analysis results was guaranteed by participating in an international proficiency test. Analysis was performed on a High-Performance Liquid Chromatography (HPLC) device with Diode Array Detector (DAD) and Refractive Index (RI) detectors-The HMF levels of 5 honey samples were 2 determined to exceed the legal limit (40 mg kg -1 ). It is revealed by the current study that the honey sold on the roadside is not safe in terms of toxic HMF. In addition, 5 samples were not found to comply with the regulation in terms of glucose + fructose content and 2 samples in terms of fructose/glucose ratio. Thus, it has also been determined that these honeys are not reliable in terms of purity.