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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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