Floral Origin Of Honey Research Articles

Screening of Volatile Composition of Lavandula hybridaReverchon II Honey Using Headspace Solid‐Phase Microextraction and Ultrasonic Solvent Extraction

The volatiles of unifloral Lavandula hybrida Reverchon II honey were isolated by means of headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE) and analyzed by gas chromatography and mass spectrometry (GC, GC/MS). A total of 23 compounds were identified in the headspace with hexan-1-ol, hexanal, acetic acid, hotrienol, and 2-phenylacetaldehyde as the principal components. Three solvents of different polarity were used for USE, and a total of 53 compounds were identified. The extracts with pentane/Et(2)O 1 : 2 (v/v) were the most representative for USE method containing the majority of the honey floral origin compounds and potential biomarkers (hexanol, acetic acid, butane-1,3-diol, butane-2,3-diol, benzoic acid, coumarin, and 2-phenylacetic acid). The total number of identified compounds (USE and HS-SPME) was 59. In general, the comparison with volatiles of other lavandin honeys of different geographic origins indicated several similarities, while acetic and formic acids were identified with high percentages in L. hybrida Reverchon II honey.

Characterisation of the phenolic and flavonoid fractions and antioxidant power of Italian honeys of different botanical origin

AbstractBACKGROUND: Twenty‐seven Italian honey samples of different floral origin were analysed for total phenolic and flavonoid contents by a spectrophotometric method and for antioxidant power and radical‐scavenging activity by the ferric‐reducing/antioxidant power (FRAP) and 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) assays respectively. In addition, the phenolic and flavonoid profiles were analysed using high‐performance liquid chromatography with UV detection (HPLC‐UV).RESULTS: The results of this study showed that honey contains copious amounts of phenolics and flavonoids. HPLC‐UV analysis showed a similar qualitative polyphenolic profile for all honey samples analysed. The main difference among samples was in the contribution of individual analytes, which was affected by floral origin. Total phenolic and flavonoid contents varied from 60.50 to 276.04 mg gallic acid equivalent kg−1 and from 41.88 to 211.68 mg quercetin equivalent kg−1 respectively. The antioxidant capacity was high and differed widely among samples. The FRAP value varied from 1.265 to 4.396 mmol Fe2+ kg−1, while the radical‐scavenging activity expressed as DPPH‐IC50 varied from 7.08 to 64.09 mg mL−1. Correlations between the parameters analysed were found to be statistically significant (P < 0.05).CONCLUSION: The present study shows that honey contains high levels of phenolics and flavonoids and that the distribution of these compounds is influenced by the honey's floral origin. Copyright © 2009 Society of Chemical Industry

Classification of Italian Honeys by 2D HR-NMR

The importance of honey has been recently increased because of its nutrient and therapeutic effects, but the adulteration of honey in terms of botanical origin has increased, too. The floral origin of honeys is usually determined using melisso-palynological analysis and organoleptic characteristics, but the application of these techniques requires some expertise. A number of papers have confirmed the possibility of characterizing honey samples by selected chemical parameters. In this study high-resolution nuclear magnetic resonance (HR-NMR) and multivariate statistical analysis methods were used to identify and classify honeys of five different floral sources. The 71 honey samples (robinia, chestnut, citrus, eucalyptus, polyfloral) were analyzed by HR-NMR using both 1H NMR and heteronuclear multiple bond correlation spectroscopy (HMBC). Spectral data were analyzed by application of unsupervised and supervised pattern recognition and multivariate statistical techniques such as principal component analysis (PCA) and general discriminant analysis (GDA). The use of 1H-(13)C HMBC coupled with appropriate statistical analysis seems to be an efficient technique for the classification of honeys.

Assessment of the floral origin of honey by SDS-page immunoblot techniques.

We report on the development of a novel alternative method for the assessment of floral origin in honey samples based on the study of honey proteins using immunoblot assays. The main goal of our work was to evaluate the use of honey proteins as chemical markers of the floral origin of honey. Considering that honeybee proteins should be common to all types of honey, we decided to verify the usefulness of pollen proteins as floral origin markers in honey. We used polyclonal anti-pollen antibodies raised in rabbits by repeated immunization of Sunflower (Elianthus annuus) and Eucalyptus (Eucalyptus sp.) pollen extracts. The IgG fraction was purified by immunoaffinity. These antibodies were verified with nitrocellulose blotted pollen and unifloral honey protein extracts. The antibodies anti-Sunflower pollen, bound to the 36 and 33 kDa proteins of Sunflower unifloral honey and to honey containing Sunflower pollen; and the antibodies anti-Eucalyptus sp. pollen bound to the 38 kDa proteins of Eucalyptus sp. unifloral honey in immunoblot assays. Satisfactory results were obtained in differentiating between the types of pollen analyzed and between Sunflower honey and Eucalyptus honey with less cross reactivity with other types of honey from different origin and also with good sensitivity in the detection. This immunoblot method opens an interesting field for the development of new antibodies from different plants, which could serve as an alternative or complementary method to the usual melissopalynological analysis to assess honey floral origin.

HONEY CARBOHYDRATE ANALYSIS BY HPLC, WITH ELECTROCHEMICAL DETECTION, USING A NI-CR ALLOY ELECTRODE

Honey carbohydrates were analyzed by high performance anion exchange liquid chromatography with constant potential amperometric detection at a nickel-chromium (80:20) alloy electrode. The sugars are oxidized by a surface catalyzed process proposed to involve Ni(II)/Ni(III) oxyhydroxides, which are formed at approximately 0.500 V (Saturated Calomel as reference electrode). The honey content of glucose, fructose, and sucrose is determined in less than 15 minutes per sample. The high sensibility achieved with this alloy electrode allowed for the analysis of disaccharides and oligosaccharides usually present in honey as minor components. The analysis of these carbohydrates may be useful for the determination of the floral origin of honey.

Isolation, identification and quantitative determination of the norisoprenoid (S)-(+)-dehydrovomifoliol in honey

In connection with investigations on flavour-related carbonyl compounds and the chemical classification of the geographical and floral origin of honey, the compound (S)-(+)-dehydrovomi folio [4-cyclohexene-3-one-6-hydroxy-1,1,5-trimethyl-6-(3oxo-l-butenyl)] was isolated from heather honey by HPLC and identified for the first time in honey by ultraviolet, infrared and nuclear-magnetic-resonance spectroscopy, mass spectrometry and polarimetry. After the isolation of the carbonyl compounds by derivatisation with Girard-T reagent and gas chromatography, heather honeys showed an (S)-(+)-dehy-drovomifoliol content of 56–264 mg/kg, whereas honeys from eight other floral origins contained only 0.033 to 6 mg/kg of this compound. The isolated compound was odourless, but the great difference in the (S)-(+)-dehydrovomifoliol content between heather honey and the honeys of other floral origin may offer the possibility of determining adulterations of heather honey.

Seasonal Pollen Analysis of Nectar from the Hive and of Extracted Honey

SummaryIn 1979 a comparison was made between pollens identified in samples of fresh nectar taken from 3 hives, and in the honey harvested from the same hives. Certain differences indicate the need for wider studies of the pollen analysis of such nectar, in relation to the assessment of the floral origin of honey from its pollen analysis. The data also indicate some pronounced differences in foraging patterns between the colonies.