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In this study, phenolic profile and antioxidant activity of 60 Turkish honey samples of nineteen different floral origins were evaluated by ultra-performance liquid chromatography with electrospray ionization coupled to tandem mass spectrometry, providing the identification of 32 phenolic compounds. Thyme (1051.58 mg/kg), pine (994.18 mg/kg), carob (935.03 mg/kg), eucalyptus (814.46 mg/kg), rhododendron (680.71 mg/kg), heather (562.59 mg/kg), cedar (561.83 mg/kg), and euphorbia (501.64 mg/kg) present significantly high phenolic content. Moreover ferulic, homogentisic, gentisic, syringic, 3,4-dihydroxybenzoic, caffeic, vanillic, p-coumaric, 4-hydroxy benzoic, and trans-2-hydroxy cinnamic acids were the most abundant of the determined compounds. The antioxidant activities of the honeys were evaluated by β-carotene-linoleic acid inhibition, DPPH free radical scavenging activity and ABTS + cation radical scavenging activity which were measured as IC 50 : 10.87-48.23 µg/mL, SC 50 : 54.33-99.40 µg/mL and SC 50 : 10.33-41.20 µg/mL, respectively. Phenolic compounds are considered antioxidant constituents, and they could be stated as components that account for antioxidant activity in Turkish honeys.

This work was conducted to evaluate the quality of 54 honey samples from eighteen different origins from Turkey. Physicochemical properties were examined according to ADAC methods, total phenolic and flavonoid contents by a spectrophotometric method and authenticity of honeys by Combustion Module -Cavity Ring-Down Spectroscopy (CM-CRDS). The microscopic analysis of honey sediment (mellissopalynology) was carried out to identify and count the pollen to provide qualitative indicators to confirm botanical origin. The moisture, electrical conductivity and free acidity of honeys ranged from 15.56 to 18.39%, 0.143 to 2.006 mS.cm . The highest proline was determined in thyme honey. The results showed that honeys contained eminent amounts of phenolics and flavonoids. δ 13 C values of honeys were more negative than -23.5‰. The C 4 % sugar ratios were lower than 7% value. The lowest glucose-fructose content was observed in eucalyptus, cedar and pine honey samples. The results obtained for physicochemical characteristics, total phenolic and flavonoid contents an authenticity analysis of Turkish honeys indicate a good quality level, adequate processing, good maturity and freshness. The discrimination between honey types was achieved by PCA.Keywords: Combustion Module-Cavity Ring-Down Spectroscopy; C 4 sugar; unifloral honeys; diastase; proline Practical Application: Honey market is a large part of the economy for many countries. Unfortunately due to large market profit for honey sales, adulteration is extremely widespread. This study indicated the results of analysis of the reliable and high-throughput instrument Combustion Module-Cavity Ring-Down Spectroscopy (CM-CRDS) for the determination of C 4 sugar adulteration in honey for the first time. We consider that CM-CRDS will be useful for food control and analysis. Additionally, the present research furnished a detailed qualification of honey samples from eighteen different Turkish origins in terms of chemical and physicochemical properties.

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The n-hexane, chloroform, ethyl acetate and ethyl alcohol extracts of the aerial parts of Centaurea ensiformis, endemic to Turkey, have been assessed for antimicrobial and antioxidant activities. The chemical composition of the hexane extract of this plant was determined. The antimicrobial activities on microorganisms, including multiple antibiotic resistant bacteria, were evaluated using the disc diffusion method. The antioxidant activities were determined by using four complementary in vitro assays: inhibition of 2,2-diphenyl-1-picrylhydrazyl radical, total antioxidant activity, and the total amount of phenolic and flavonoid compounds. The structure of the active extract was elucidated by: thin layer chromatography, column chromatography, gas chromatography or gas chromatography-mass spectrometry. The various extracts of C. ensiformis inhibited the growth of tested bacteria. All the C. ensiformis extracts had no effect on the yeasts. The total antioxidant activity increased with the increasing amount of the extracts (20, 40, 80 and 160 microg), which contained linoleic acid emulsion. The major compounds of the hexane extract of the plant were caryophyllene oxide (28.72%), spathulenol (17.81%), eudesmol (13.03%) and beta-bourbonene (8.51%).

An accurate, reliable and fast multianalyte/multiclass ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the simultaneous analysis of 23 pharmaceuticals, belonging to different classes amphenicols, sulfonamides, tetracyclines, in honey samples. The method developed consists of ultrasonic extraction followed by UPLC-ESI-MS/MS with electrospray ionization in both positive mode and negative mode. The influence of the extraction solvents and mobile phase composition on the sensitivity of the method, and the optimum conditions for sample weight and extraction temperature in terms of analyte recovery were extensively studied. The identification of antibiotics is fulfilled by simultaneous use of chromatographic separation using an Acquity BEH C 18 (100 mm x 2.1 mm, 1.7 µm) analytical column with a gradient elution of mobile phases and tandem mass spectrometry with an electrospray ionization. Finally, the method developed was applied to the determination of target analytes in honey samples obtained from the local markets and several beekeepers in Muğla, Turkey. Ultrasonic-extraction of pharmaceuticals from honey samples is a well-established technique by UPLC-ESI-MS/MS, the uniqueness of this study lies in the simultaneous determination of a remarkable number of compounds belonging to 23 drug at the sub-nanogram per kilogram level.Keywords: antibiotics; fast method; honey; UPLC-ESI-MS/MS; chloramphenicol.Practical Application: Honey is one of the healthy foods across the world. Food safety is an important issue regarding residues of pharmaceutical drugs. The developed method proposed simultaneous analysis of analysis of twenty-three veterinary pharmaceuticals in honey. A fast and sensitive multianalyte/multiclass ultra-performance liquid chromatography-tandem mass spectrometry with electrospray ionization (UPLC-ESI-MS/MS) method provides the analysis of 50 honey samples in 50 minutes for food and laboratory sectors, and benefits safe food consumption.