Determining the Levels of Acrylamide in Some Traditional Foods Unique to Turkey and Risk Assessment.

In this study, exposure risk assessment was made by determining the acrylamide levels of some traditional foods frequently consumed by the Turkish society and registered geographical indication. For this purpose, acrylamide levels of 20 traditional foods [7 meat products, 3 loaves of bread, 3 bagels (simit), and 7 desserts] obtained from different bakeries, patisseries, and restaurants were determined by LC-MS/MS. Acrylamide levels were determined between 12.7 - 299 µg/kg in meat products, 11.8 - 69.3 µg/kg in bread, 11.8 - 179 µg/kg in bagels, 11.7 - 85.0 µg/kg in baked desserts, and 32.3 - 527 µg/kg in deep-fried desserts. According to the portion size, the food with the highest acrylamide level in meat products is Adana kebab (17.70 µg/180 g). Formulation and cooking techniques are thought to be the main determinants of acrylamide level detected in traditional foods. Dietary acrylamide exposure was calculated according to the deterministic model. Exposure was calculated as 0.20, 0.53, and 0.98 µg/kg bw per day for good, average and bad scenarios, respectively. The calculated acrylamide exposure value is below the reference values stated by FAO/WHO. The acrylamide dietary exposure was not of concern concerning neurotoxicity and carcinogenicity. The results can be used to reduce acrylamide levels in foods and risk assessment studies.

Chemical Variation, Antimicrobial, Nitric Oxide Scavenging Activities and Tyrosinase Inhibition of Essential Oils and Solvent Extracts from Filipendula vulgaris Moench Growing in Turkey.

Volatile organic compositions of the essential oils (EOs), solid-phase microextraction (SPME) and SPME of n-hexane extracts from the flower and stem-leaf of Filipendula vulgaris (F. vulgaris) were analyzed by GC-FID/MS. A total of 107 constituents were characterized, flower and stem-leaf parts of the plant were found to contain different volatile organic compounds. Tricosane (29.6%), n-nonanal (20.5%) were identified as the main components in the essential oil of the flower, while phytol (35.2%) was found to be a major constituent in the essential oil of stem-leaf. Benzaldehyde (56.0%) and n-nonanal (31.6%) were the major groups in the SPME of stem-leaf and flower, respectively. The volatiles for the SPME of n-hexane extracts of the flower and stem-leaf of F. vulgaris were predominated by aromatic compounds (75.0% and 78.5%) and ketones (18.1% and 10.1%), respectively. On the other hand, a total of terpene compounds was found at the most in the EO of the stem-leaf part of the plant (48.6%). In addition, antimicrobial, tyrosinase inhibition, and nitric oxide scavenging activities of the n-hexane (H), methanol (M), aqueous extracts (A) and EOs of F. vulgaris were investigated. EOs and methanol extracts of flower and stem-leaf had high antimicrobial activity against tested various microorganisms. However, n-hexane extracts of the flower and stem-leaf only displayed activity against Mycobacterium smegmatis. Methanol extracts of flower and stem-leaf possessed the best tyrosine inhibition and NO scavenging activity.

A novel endo-ß-1,4-xylanase from Pediococcus acidilactici GC25; purification, characterization and application in clarification of fruit juices.

A novel extracellular xylanase was purified and characterized from Pediococcus acidilactici GC25 (GenBank number: MF289522). The purification was 4.6-fold with a yield of 43.61% through acetone precipitation, Q-Sepharose, and CM-Sepharose ion change chromatography. The molecular weight of the enzyme was 48.15 kDa, and the optimum pH and temperature were 7.0 and 40 °C, respectively. The maximum activity was observed between 20 and 50 °C. Although it was active within a wide pH range (pH 2.0-9.0), it retained over 85% of its activity after 24 h incubation; and over 70% of its activity after 168 h incubation in neutral and alkaline pH. It was observed that the enzyme showed high stability with K+, Ba2+, Cd2+, Co2+, Sr2+, Mg2+, Ca2+, Al3+, Zn2+, and Ni2+ ions. The Km and Vmax for the xylanase were 3.10 mg mL-1 and 4.66 U/mg protein, respectively. It was determined that treatment of different fruit juices with P. acidilactici GC25 xylanase improved the clarification. The highest increase in the reducing sugar amount and decrease in the turbidity was 24.47 ±â€¯1.08 and 21.22 ±â€¯0.58 for peach juice at 0.15 U/mL enzyme concentration. These results showed that the xylanase purified from P. acidilactici GC25 may have a wide potential in biotechnological processes of the food and baking industry.

Piperazine-azole-fluoroquinolone hybrids: Conventional and microwave irradiated synthesis, biological activity screening and molecular docking studies.

A series of new 1,2,4-triazole and 1,3,4-oxadiazole derivatives was obtained via several steps sequential reactions of phenyl piperazine. Then, these compounds were converted to the corresponding fluoroquinolone hybrids via one pot three component Mannich reaction. All the reactions were examined under conventional and microwave mediated conditions, and optimum conditions were determined. The effect of different solvents and microwave power on microwave prompted reactions was investigated as well. All the newly synthesized compounds were characterized by FTIR, 1H NMR, 13C NMR and EI MS spectral techniques. The antimicrobial activity, DNA gyrase and Topoisomerase IV inhibition potentials were performed. The results obtained showed that fluoroquinolone hybrids possess good antimicrobial activity. Moreover, Fluoroquinolone-azole-piperazine hybrids synthesized in the present study displayed excellent DNA gyrase inhibition. To unveil the interaction mode of compounds to receptor, a molecular docking study was performed. With an average least binding energy of -9.5 kcal/mol, all compounds were found to have remarkable inhibitory potentials against DNA gyrase (E. coli).

New xylanolytic enzyme from Geobacillus galactosidasius BS61 from a geothermal resource in Turkey.

In this study, isolation, conventional and molecular characterizations of ten thermophilic bacteria from Rize/Ayder were carried out. Xylanase from Geobacillus galactosidasius BS61 (GenBank number: KX447660) was purified by acetone precipitation, Diethylaminoethyl-cellulose and Sephadex G-100 chromatographies. The xylanase of G. galactosidasius BS61 in clarifying fruit juice was also investigated. Enzyme was purified 29.80-fold with 75.18% yield; and molecular weight was determined as 78.15 kDa. The optimum temperature of xylanase was 60 °C. The enzyme activity was maintained fully after 24 h and over 50% after 168 h at pH 4.0-10.0, while optimum pH was 7.0. Km and Vmax for beech wood xylan were measured as 3.18 mg mL-1, 123 U mg protein-1. In addition, Ca2+, Na+, Al3+, Zn2+, Cd2+, Mg2+, Ni2+, Cu2+ had decreasing effect on enzyme activity, while enzyme activity had been protected against anions, especially HSO3- and HPO42- stimulated enzyme activity. Xylanase applications (with 15 U/mL enzyme activity) in orange and pomegranate juices were increased; and the sugar and turbidity amounts were reduced 17.36% ±â€¯1.18 and 30.52 ±â€¯1.23, respectively. These results indicated that the xylanase of G. galactosidasius BS61 has biotechnological potential in juice clarification due to its stability against metal ions, chemicals and high pH-values.

Determination and characterization of thermostable esterolytic activity from a novel thermophilic bacterium Anoxybacillus gonensis A4.

A novel hot spring thermophile, Anoxybacillus gonensis A4 (A. gonensis A4) was investigated in terms of capability of tributyrin degradation and characterization of its thermostable esterase activity by the hydrolysis of p-nitrophenyl butyrate (PNPB). It was observed that A. gonensis A4 has an esterase with a molecular weight of 62 kDa. The extracellular crude preparation was characterized in terms of substrate specificity, pH and temperature optima and stability, kinetic parameters and inhibition/activation behaviour towards some chemicals and metal ions. Tributyrin agar assay showed that A. gonensis A4 secreted an esterase and V(max) and K(m) values of its activity were found to be 800 U/L and 176.5 microM, respectively in the presence of PNPB substrate. The optimum temperature and pH, for A. gonensis A4 esterase was 60-80 degrees C and 5.5, respectively. Although the enzyme activity was not significantly changed by incubating crude extract solution at 30-70 degrees C for 1 h, the enzyme activity was fully lost at 80 degrees C for same incubation period. The pH-stability profile showed that original crude esterase activity increased nearly 2-fold at pH 6.0. The effect of some chemicals on crude esterase activity indicated that A. gonensis A4 produce an esterase having serine residue in active site and -SH groups were essential for its activity.