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Honeydew is excreted by aphids as a sweet waste and nectar is floral honey. Honeydew and nectar are complicated samples which consist of various sugars and amino acids. In this work, a simple ion chromatography with column-switching method was developed for the simultaneous analysis of 8 monosaccharides and oligosaccharides in honeydew and nectar. A reversed-phase column was used as a pretreatment column to eliminate organics on-line and sugars were eluted from a collection loop to analytical column by using column-switching technique. This method showed good linearity ( r ⩾ 0.9994) and afforded low limits of detection ranging from 1.55 to 10.17 μg L −1 for all the analytes. Recoveries ranged from 95% to 105% and repeatability results were acceptable with relative standard deviation of less than 3.21% ( n = 6). This method was successfully applied to quantification of these sugars in honeydew and nectar. These results showed honeydew had much more oligosaccharides than nectar. [ABSTRACT FROM AUTHOR]

This study investigated some physico-chemical and biochemical characteristics of different honey types belonging to Turkish flora. Sixty-two honey samples were examined on the basis of pollen analyses, including 11 unifloral honeys (chestnut, heather, chaste tree, rhododendron, common eryngo, lavender, Jerusalem tea, astragalus, clover and acacia), two different honeydew honeys (lime and oak), and 7 different multifloral honeys. Electrical conductivity, moisture, Hunter color values, HMF, proline, diastase number, and sugar analyses of the honey samples were assessed for chemical characterization. Some phenolic components were analyzed by reverse phase high performance liquid chromatography (RP-HPLC) to determine honeys’ phenolic profiles. Total phenolic compounds, total flavonoids, ferric reducing antioxidant capacity (FRAP) and 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging activity were measured as antioxidant determinants. The study results confirm that physico-chemical and biological characteristics of honeys are closely related to their floral sources, and that dark-colored honeys such as oak, chestnut and heather, have a high therapeutic potential. [ABSTRACT FROM AUTHOR]

Consumers are exhibiting increasing interest in honeydew honey, principally due to its functional properties. Some plants can be sources of honeydew honey, but in north-western Spain, this honey type only comes from Quercus pyrenaica. In the present study, the melissopalynological and physicochemical characteristics and the antioxidant properties of 32 honeydew honey samples are described. Q. pyrenaica honeydew honey was defined by its colour, high pH, phenols and flavonoids. Multivariate statistical techniques were used to analyse the influence of the production year on the honey's physicochemical parameters and polyphenol content. Differences among the honey samples were found, showing that weather affected the physicochemical composition of the honey samples. Optimal conditions for oak growth favoured the production of honeydew honey. [ABSTRACT FROM AUTHOR]

Abstract: An NMR-based approach for rapid differentiation of oak honeydew honey from all other honey types (floral and other honeydew honeys) was proposed. It is based on the identification of the signals of the protons and the carbon of the methylene group of quercitol in the 1H and 13C NMR spectra of honey. The presence of quercitol was supported by TOCSY spectroscopy. Quercitol is a deoxyinositol which is regarded as a good taxonomic marker for the genus Quercus. All samples of oak honeydew honey contained quercitol, while in floral honey samples and honeydew honeys from fir and spruce it was absent. In addition, the described approach is promising with respect to quercitol quantification in honey by qNMR. [Copyright &y& Elsevier]

Abstract: Multivariate analysis was applied on physicochemical parameters (moisture, water activity, electric conductivity, colour, hydroxymethyl furfural, acidity, pH, proline, diastase and invertase), sugar composition (fructose, glucose, sucrose, maltose, isomaltose, trehalose, turanose and melezitose) and palinological parameters determined in blossom and suspected honeydew honeys in order to differentiate them. The majority of the physicochemical, sugar composition and palinological parameters evaluated presented significant differences in the mean values between the suspected honeydew and blossom honeys, with the exception of moisture, water activity, diastase, fructose and maltose. Blossom honey samples tend to differentiate from the suspected honeydew honeys after applying factor analysis on the physicochemical parameters and sugar composition. Stepwise linear discriminant analysis allows the correct classification of all blossom honeys, and only one honeydew honey was erroneously included as blossom honey. So, the use of multivariate analysis on physicochemical parameters and sugar composition can be a useful tool to differentiate these types of honeys. [ABSTRACT FROM AUTHOR]

Abstract: In the present work we report on the compounds characteristic of larval food (royal jelly, RJ) of the honeybee (Apis mellifera L.) that were identified in 34 different samples of genuine honey and in 3 sugar-adulterated “herbal honeys” by using solid-phase extraction and gas chromatography–mass spectrometry (SPE/GC–MS). The unique feature of RJ is a set of C8, C10 and C12 hydroxy fatty acids. In all, ten acids characteristic of this bee product were identified in different combinations in the analysed honey samples, namely: 7- and 8-hydroxyoctanoic, 3-hydroxydecanoic, 9-hydroxydecanoic, 9-hydroxy-2-decenoic, 10-hydroxydecanoic, 10-hydroxy-2-decenoic (10-HDA), 3,10-dihydroxydecanoic, 2-octene-1,8-dioic and 2-decene-1,10-dioic acids. The higher relative abundance of these compounds was determined in genuine honeydew and heather honeys, and in “herbal honeys” (23.8–40.8, 18.2–48.5, and 27.0–48.4μg/g, respectively). Since RJ is known to have strong antibiotic efficacy, our results suggest that a part of the non-peroxide antibacterial activity of honey might be of bee origin. [ABSTRACT FROM AUTHOR]

Abstract: The concentrations of 23 chemical elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Pb, Sb, Se, Sr, Th, Tl, U, Zn) were determined in 51 honey samples of different botanical origin produced in Siena County (Italy). K, Ca, Na and Mg were the most abundant elements, with mean contents of 1195, 257, 96.6 and 56.7mg/kg, respectively. The Fe, Zn and Sr contents generally ranged from 1 to 5mg/kg. Except for Ba, Cu, Mn and Ni, the trace element contents were below 100μg/kg. The analytical data indicated a good level of quality of the honeys, especially with regard to the concentrations of toxic trace elements, such as As, Cd, Pb and Sb, and suggested a significant influence of the botanical origin on the element composition. Some local geological and geochemical features also seemed to affect the chemistry of the honey. [Copyright &y& Elsevier]

Abstract: Aroma compounds were extracted from three cultivars of muskmelon (Cucumis melo L.) by solid-phase microextraction and analysed by gas chromatography–mass spectrometry. Sulfur-containing esters and compounds containing a straight six-carbon chain were present at high concentrations in cantaloupe melons. Compounds containing a straight nine-carbon chain were at high concentrations in honeydew melons. Methyl esters were present at the highest levels in Galia melons. The sensory properties of the three melons were also compared. Cantaloupe melons were associated with sweet, floral and fruity aromas and a persistent aftertaste. Galia melons possessed the strongest cucumber-like flavours, while cucumber aroma and sweet flavour scored highly in honeydew melons. [Copyright &y& Elsevier]

• Differentiation between honeydew and chestnut honey using multivariate analysis. • Castanea , Cytisus , color, RSA, Mg and trehalose variables dominated grouping by PCA. • Honeydew and chestnut (97.6%) honey were correctly classified by LDA. Oak honeydew and chestnut honeys often share the same production area in Atlantic landscapes. Consequently these honeys have common physicochemical properties and pollen composition, making their differentiation by routine methods, a difficult task. The increase in the demands of consumers for clear honey labelling, identifying floral make-ups and the substantial health properties of both honey types, make it necessary to improve methods to differentiate the honeys. Statistical multivariate techniques were used to study the differences in the physicochemical composition and pollen spectra between chestnut honey and oak honeydew honey. Palynological analysis, moisture, pH, electrical conductivity, hydroxymethylfurfural, diastase number, colour, phenolic content, minerals and sugars were used for this purpose. The variables that had more weight in the differentiation by principal component analysis were Castanea , Cytisus type, CIELab coordinates (a* and L), RSA, Mg and trehalose; 97.6% of the honey samples were correctly classified by linear discriminant analysis. [ABSTRACT FROM AUTHOR]