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Jerkovic I.,University of Split | Hegic G.,University of Zagreb | Marijanovic Z.,Marko Marulic Polytechnic in Knin | Bubalo D.,University of Zagreb
Molecules | Year: 2010

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.

Jerkovic I.,University of Split | Tuberso C.I.G.,University of Cagliari | Gugic M.,Marko Marulic Polytechnic in Knin | Drabubalo G.,University of Zagreb
Molecules | Year: 2010

Samples of unifloral sulla (Hedysarum coronarum L.) honey from Sardinia (Italy) were analysed. To investigate the chemical composition of the honey volatiles two solvent systems were used for ultrasonic solvent extraction (USE): 1) a 1:2 (v/v) pentane and diethyl ether mixture and 2) dichloromethane. All the extracts were analysed by GC and GC/MS. These procedures have permitted the identification of 56 compounds that include norisoprenoids, benzene derivatives, aliphatic compounds and Maillard reaction products. Norisoprenoids were the major compounds in both extracts, dominated by vomifoliol (5.3-11.2%; 9.6-14.0%) followed by minor percentages of other norisoprenoids such as a-isophorone, 4-ketoisophorone, 3-oxo-a-ionol or 3-oxo-a-ionone. Other abundant single compounds in the extracts were 3-hydroxy-4-phenylbutan-2-one (0.8-5.4%; 0.6-5.7%) and methyl syringate (3.0-5.7%; 2.2-4.1%). The composition of the volatiles and semi-volatiles in the obtained extracts suggests that sulla honey is quite distinctive relative to the other honeys that have been chemically studied by GC/MS, but no specific markers of the honey botanical origin were found. © 2010 by the authors.

Jerkovic I.,University of Split | Kus P.M.,Wroclaw Medical University | Tuberoso C.I.G.,University of Cagliari | Sarolic M.,Marko Marulic Polytechnic in Knin
Food Chemistry | Year: 2014

The case study of Polish Salix spp. honey was compared with published data on willow honey from other regions. GC-FID/MS (after HS-SPME and ultrasonic solvent extraction) and targeted HPLC-DAD were applied. Phenolic content, FRAP/DPPH assays and the colour coordinates were determined spectrophotometrically. Beside ubiquitous linalool derivatives, borneol (up to 10.9%), bicyclic monoterpenes with pinane skeleton (pinocarvone up to 10.6%, myrtenal up to 4.8% and verbenone up to 3.4%) and trans-β-damascenone (up to 13.0%) dominated in the headspace. The main compounds of the extractives were vomifoliol (up to 39.6%) and methyl syringate (up to 16.5%) along with not common 4-hydroxy-3-(1-methylethyl)benzaldehyde (up to 11.1%). Abscisic acid (ABA) was found (up to 53.7 mg/kg) with the isomeric ratio (Z,E)-ABA:(E,E)-ABA = 1:2. The honey exhibited low antioxidant potential with pale yellow colour. The composition of Polish willow honey is similar to Mediterranean willow honeys with several relevant differences. © 2013 Elsevier Ltd. All rights reserved.

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 | Year: 2014

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.

Tuberoso C.I.G.,University of Cagliari | Jerkovic I.,University of Split | Sarais G.,University of Cagliari | Congiu F.,University of Cagliari | And 2 more authors.
Food Chemistry | Year: 2014

CIE (Commission Internationale de l'Eclairage) Lâ̂ -Cabâ̂ - habâ̂̃ color coordinates for 305 samples of 17 unifloral honeys types (asphodel, buckwheat, black locust, sweet chestnut, citrus, eucalyptus, Garland thorn, honeydew, heather, lime, mint, rapeseed, sage, strawberry tree, sulla flower, savory and thistle) from different geographic locations in Europe were spectrophotometrically assessed and statistically evaluated. Preliminary separation of unifloral honeys was obtained by means of Lâ̂ --Cabâ̂ - color coordination correlation. Hierarchical Cluster Analysis (HCA) revealed an expected segregation of the honeys types according to their chromatic characteristics. Principal Component Analysis (PCA) allowed to obtain a more defined distinction of the 17 unifloral honey types, particularly when using 3D graphics. CIE Lâ̂ -Cabâ̂ - habâ̂̃ color coordinates were useful for the identification of several honey types. The proposed method represents a simple and efficient procedure that can be used as a basis for the authentication of unifloral honeys worldwide. © 2013 Elsevier Ltd. All rights reserved.

Jerkovic I.,University of Split | Marijanovic Z.,Marko Marulic Polytechnic in Knin | Staver M.M.,University of Rijeka
Molecules | Year: 2011

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.

Jerkovic I.,University of Split | Marijanovic Z.,Marko Marulic Polytechnic in Knin
Molecules | Year: 2010

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.

Jerkovic I.,University of Split | Marijanovic Z.,Marko Marulic Polytechnic in Knin
Chemistry and Biodiversity | Year: 2010

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.

Jerkovic I.,University of Split | Tuberoso C.I.G.,University of Cagliari | Kasum A.,University of Split | Marijanovic Z.,Marko Marulic Polytechnic in Knin
Chemistry and Biodiversity | Year: 2011

Chemical analysis of Asphodelus microcarpus Salzm. et Viv. honey is of great importance, since melissopalynology does not allow the unambiguous determination of its botanical origin. Therefore, the volatile compounds of eight unifloral asphodel honeys have been investigated for the first time. The honey extracts were obtained by headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) and analyzed by GC and GC/MS. In the honey headspace, 31 volatile compounds were identified with high percentages of 2-phenylacetaldehyde (2; 14.8-34.7%), followed by somewhat lower percentages of methyl syringate (1; 10.5-11.5%). Compound 2 is not a specific marker of the botanical origin of the honey, but its high percentage can be emphasized as headspace characteristic of asphodel honey. The extraction solvent for all the samples was selected after extracting a representative sample with pentane, Et 2O, pentane/Et 2O 1 : 2 (v/v), and CH 2Cl 2. Compound 1 was the major constituent of all the USE extracts (46.8-87.0%). According to these preliminary results, all the honey samples were extracted by USE with the solvent pentane/Et 2O 1 : 2. A total of 60 volatile compounds were identified with 1 as predominant compound (69.4-87.0%), pointing out 1 as Asphodelus honey volatile marker. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich.

Jerkovic I.,University of Split | Kasum A.,University of Split | Marijanovic Z.,Marko Marulic Polytechnic in Knin | Tuberoso C.I.G.,University of Cagliari
Food Chemistry | Year: 2011

Sardinian abbamele is a typical product obtained from the honey recuperation from combs (traditional procedure) or by concentration of the honey diluted in water (industrial procedure). Seven abbamele samples were obtained to study the volatiles' composition, the presence of honey marker compounds and their relationship with the production procedures. The long thermal treatment applied in abbamele production caused very high (1007.0-4405.8mg/kg) HMF content (HPLC-DAD), while glucose and fructose amounts were quite similar to the honey ones (HPLC-RI). Total antioxidant activity (FRAP assay) of the samples ranged between 13.3 and 71.2mmol Fe2+/kg, while antiradical activity (DPPH assay) ranged between 3.8 and 23.3mmol TEAC/kg. Such high antioxidant values were linearly correlated with total phenol amount (1297.8-4469.5mg GAE/kg) determined by Folin-Ciocalteau method. Thermally derived furan derivatives and terpenes were abundant among the headspace volatiles (HS-SPME), particularly limonene (0.5-76.0%) that probably originated from citrus rinds' addition during abbamele production. GC and GC-MS analyses of USE isolates revealed HMF predominance as well as the honey marker compounds (if/when existing) such as methyl syringate (up to 49.2%), marker of Asphodelus microcarpus honey. High isophorone percentage (up to 30.9%) determined by HS-SPME followed by minor percentage of 4-ketoisophorone and norisoprenoids in one sample indicated Arbutus unedo L. honey use in the production. HPLC-DAD analysis confirmed the presence of specific honey markers: two samples showed high methyl syringate concentrations (150.4-120.1mg/kg) while homogentisic acid and other specific markers of A. unedo honey were found in one sample. The compared GC-MS and HPLC-DAD data proved to be useful to obtain information about the use of specific honey in the production and to verify citrus addition. © 2010 Elsevier Ltd.

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