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Jerkovic I.,University of Split | Marijanovic Z.,Marko Marulic Polytechnic in Knin | Staver M.M.,University of Rijeka

Headspace solid-phase microextraction (HS-SPME; PDMS/DVB fibre) and ultrasonic solvent extraction (USE; solvent A: pentane and diethyl ether (1:2 v/v), solvent B: dichloromethane) followed by gas chromatography and mass spectrometry (GC, GCMS) were used for the analysis of Prunus mahaleb L. honey samples. Screening was focused toward chemical composition of natural organic volatiles to determine if it is useful as a method of determining honey-sourcing. A total of 34 compounds were identified in the headspace and 49 in the extracts that included terpenes, norisoprenoids and benzene derivatives, followed by minor percentages of aliphatic compounds and furan derivatives. High vomifoliol percentages (10.7%-24.2%) in both extracts (dominant in solvent B) and coumarin (0.3%-2.4%) from the extracts (more abundant in solvent A) and headspace (0.9%-1.8%) were considered characteristic for P. mahaleb honey and highlighted as potential nonspecific biomarkers of the honey's botanical origin. In addition, comparison with P. mahaleb flowers, leaves, bark and wood volatiles from our previous research revealed common compounds among norisoprenoids and benzene derivatives. © 2011. Source

Jerkovic I.,University of Split | Hegic G.,University of Zagreb | Marijanovic Z.,Marko Marulic Polytechnic in Knin | Bubalo D.,University of Zagreb

The GC and GC/MS analyses of the solvent organic extractive from the stomach of the bees, having collected Mentha spp. nectar, revealed the presence of methyl syringate (6.6%), terpendiol I (5.0%) and vomifoliol (3.0%) that can be attributed to the plant origin. Other major compounds from the bee-stomach were related to the composition of cuticular waxes and less to pheromones. Organic extractives from Mentha spp. honey were obtained by solvent-free headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) and analyzed by GC and GC/MS. The major honey headspace compounds were hotrienol (31.1%-38.5%), 2-methoxy-4-methylphenol (0.5-6.0%), cisand trans-linalool oxides (0.9-2.8%), linalool (1.0-3.1%) and neroloxide (0.9-1.9%). Methyl syringate was the most abundant compound (38.3-56.2%) in the honey solvent extractives followed by vomifoliol (7.0-26.6%). Comparison of the honey organic extractives with the corresponding bee-stomach extractive indicated that methyl syringate and vomofoliol were transferred to the honey while terpendiol I was partially transformed to hotrienol in ripened honey. Copyright © 2010 by the authors. Source

Jerkovic I.,University of Split | Marijanovic Z.,Marko Marulic Polytechnic in Knin
Chemistry and Biodiversity

Salix spp. nectar honey volatiles of Croatian origin were analyzed by headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE), followed by gas chromatography and mass spectrometry (GC, GC/MS). Isolated volatiles were found in the honey headspace and extracts with almost exclusive distribution of several abundant compounds (e.g., phenylacetic acid, pinocembrin, 8-hydroxy-4,7-dimethylcoumarin, and 3-hydroxy-trans-β- damascone in the extracts, or safranal and lilac alcohols in the headspace). Comparison with Croatian Salix spp. honeydew honey revealed similarities regarding distribution of important shikimate pathway derivatives (e.g., high percentage of phenylacetic acid) and several norisoprenoids (α-isophorone and 4-oxoisophorone). On the other hand, distinct features of this honey were occurrence of compounds such as pinocembrin, 8-hydroxy-4,7-dimethylcoumarin, phenylacetonitrile, norisoprenoids (major ones: 3-hydroxy-trans-β- damascenone and trans-β-damascone), more pronounced variability of linalool-derived compounds, as well as the abundance of 3-methylpropanoic acid, 3-methylbutanoic acid, 2-methylpentanoic acid, and 3-methylpentan-1-ol. © 2010 Verlag Helvetica Chimica Acta AG. Source

Two samples of oak honeydew honey were investigated. Headspace solid-phase microextraction (HS-SPME) combined with GC and GC/MS enabled identification of the most volatile organic headspace compounds being dominated by terpenes (mainly cis-and trans-linalool oxides). The volatile and less-volatile organic composition of the samples was obtained by ultrasonic assisted extraction (USE) with two solvents (1:2 (v/v) pentane-diethyl ether mixture and dichloromethane) followed by GC and GC/MS analysis. Shikimic pathway derivatives are of particular interest with respect to the botanical origin of honey and the most abundant was phenylacetic acid (up to 16.4%). Antiradical activity (DPPH assay) of the honeydew samples was 4.5 and 5.1 mmol TEAC/kg. Ultrasonic solvent extracts showed several dozen times higher antiradical capacity in comparison to the honeydew. Antioxidant capacity (FRAP assay) of honeydew samples was 4.8 and 16.1 mmol Fe2+/kg, while the solvent mixture extracts showed antioxidant activity of 374.5 and 955.9 Fe2+/kg, respectively, and the dichloromethane extracts 127.3 and 101.5 mmol Fe2+/kg. © 2010 by the authors. Source

Kus P.M.,Wroclaw Medical University | Jerkovic I.,University of Split | Tuberoso C.I.G.,University of Cagliari | Marijanovic Z.,Marko Marulic Polytechnic in Knin | Congiu F.,University of Cagliari
Food Chemistry

The samples of cornflower (Centaurea cyanus L.) honey from Poland were subjected to ultrasonic solvent extraction applying the mixture of pentane and diethyl ether 1:2 v/v (solvent A) as well as dichloromethane (solvent B). The major compounds of the extracts (analysed by GC-MS/GC-FID) were C13 and C9 norisoprenoids. Among them, (E)-3-oxo-retro-a-ionol (2.4-23.9% (solvent A); 3.9-14.4% (solvent B)) and (Z)- 3-oxo-retro-a-ionol (3.7-29.9% (solvent A); 8.4-20.4% (solvent B)) were found to be useful as chemical biomarkers of this honey. Other abundant compounds were: methyl syringate (0.0-31.4% (solvent A); 0.0-25.4% (solvent B)) and 3-hydroxy-4-phenylbutan-2-one (1.6-15.8% (solvent A); 5.1-15.1% (solvent B)). HPLC-DAD analysis of the samples revealed lumichrome (4.7-10.0 mg/kg), riboflavin (1.9-2.7 mg/ kg) and phenyllactic acid (112.1-250.5 mg/kg) as typical compounds for this honey type. Antioxidant and antiradical properties as well as total phenolic content of the samples were found to be rather moderate by FRAP (ferric reducing antioxidant power), DPPH (1,1-diphenyl-2-picrylhydrazyl radical) and Folin-Ciocalteu assays, respectively. Additionally, CIE L*a*b*C*h chromatic coordinates were evaluated. Colour attributes of cornflower honey were characterised by elevated values of L/ and particularly high values of b/ and h coordinates, which correspond to medium bright honey with intense yellow colour. © 2013 Elsevier Ltd. Source

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