Geographical Origin Of Honey Research Articles

Characterization of filtered honey by electrophoresis of enzyme fractions

According to both the European Council’s Honey Directive 2001/110/EC and the present Codex Aliminerius Honey Standard, filtration of honey is permitted. After this filtration process, the microscopic determination of the botanical and geographical origin of honeys is no longer possible since all the pollen has been removed. In many honey countries, there is a considerable difference in the price of honey depending on the botanical and geographical origin. There is the risk of fraud if expensive unfiltered honey is mixed with cheap filtered honey. In this research project, a method was developed that allows the detection of mixtures of filtered and unfiltered honey. Comparative tests showed that enzyme activities, mainly sucrase, were influenced by this process. The protein content did not decrease. Sucrase was isolated by gel chromatography and analysed by gel electrophoresis. One of the two dominating protein bands with 40 kDa and 65 kDa decreased significantly after filtration, which led to a shift in the natural ratio between them. The quantitative densitometric analysis of these two protein bands allows the detection of 15% added filtered honey.

Traditional melissopalynology integrated by multivariate analysis and sampling methods to improve botanical and geographical characterisation of honeys

Melissopalynological analysis is the official test to determine the botanical and geographical origin of honey. Geographical characterisation is generally obtained by synthesising the pollen data of all available local honeys in a pollen spectrum interpreted according to palynological expertise. The subjective ability to interpret data is considered a limiting factor for this method and alternative tests are promoted. Nevertheless, melissopalynological analysis is still the most reliable test, and data, if properly exploited, could provide a large amount of information that is generally disregarded. The aim of our work was to apply a new experimental approach for honey sampling, and a statistical multivariate analysis of melissopalynological data. The study was conducted in the Sorrento-Amalfi Peninsula (southern Italy) where 36 hives were positioned in 12 experimental stations distributed in three main land-use types (citrus orchards, chestnut woods and Mediterranean maquis). The new approach proved to be useful for the comprehensive evaluation of honey variability across time and space, allowing objective identification of the pollen types as markers of a given geographical area.

Carbon and Nitrogen Natural Stable Isotopes in Slovene Honey: Adulteration and Botanical and Geographical Aspects

Isotope parameters (δ(13)C(honey), δ(13)C(protein), δ(15)N) were determined for 271 honey samples of 7 types (black locust, multifloral, lime, chestnut, forest, spruce, and fir honeys) from 4 natural geographical regions of Slovenia. Carbon and nitrogen stable isotope ratios were measured to elucidate the applicability of this method in the identification of the botanical and geographical origin of honey and in honey adulteration. Only 2.2% of the samples were adulterated according to the internal standard carbon isotope ratio analysis method. Botanical origin did not have any major influence on the honey isotope profiles; only black locust honey showed higher δ(13)C values. Some differences were seen across different production years, indicating that the influence of season should be further tested. Statistical and multivariate analyses demonstrated differences among honeys of various geographical origins. Those from the Alpine region had low δ(13)C (-26.0‰) and δ(15)N values (1.1‰); those from the Mediterranean region, high δ(13)C (-24.6‰) and medium δ(15)N values (2.2‰); those from the Pannonian region, medium δ(13)C (-25.6‰) and high δ(15)N value (3.0‰); and those from the Dinaric region, medium δ(13)C (-25.7‰) and low δ(15)N values (1.4‰).

DNA Barcoding for Honey Biodiversity

Honey is produced by honeybees from nectar and from secretions of living plants. It reflects the honeybees’ diet and the local plant communities. Honey also shows different plant compositions in different geographical locations. We propose a new method for studying the plant diversity and the geographical origin of honey using a DNA barcoding approach that combines universal primers and massive parallel pyrosequencing. To test this method we use two commercial honeys, one from a regional origin and one composed of a worldwide mix of different honeys. We demonstrate that the method proposed here is fast, simple to implement, more robust than classical methods, and therefore suitable for analyzing plant diversity in honey.

Erratum to “Tracing the geographical origin of honeys based on volatile compounds profiles assessment using pattern recognition techniques” [Food Chemistry 118 (2009) 171–176

Erratum to “Tracing the geographical origin of honeys based on volatile compounds profiles assessment using pattern recognition techniques” [Food Chemistry 118 (2009) 171–176

APPLICATION OF ELECTRONIC NOSE IN HONEY GEOGRAPHICAL ORIGINCHARACTERISATION

Honey volatile compounds were analysed by means of electronic nose, with the aim to capture honey aroma profile. 49 samples of black locust (Robinia pseudoacacia L.) and 16 of chestnut (Castanea sativa Mill.) honeys were analysed. Their botanical origin and physicochemical properties were analysed in accredited laboratory Geographical origin of samples has been known from interviews with beekeepers. Data obtained by electronic nose analysis were further analysed by principal component analysis (PCA) in order to determine differences among volatile profiles of samples with the same botanical origin but with different geographical origin. PCA result showed that honey samples from geographically close regions tend to group together, while those of distant geographical regions show differences though they are of the same botanical origin. Those results imply possibility to use electronic nose as a tool for honey geographical origin determination.

Major flavonoids of Argentinean honeys. Optimisation of the extraction method and analysis of their content in relationship to the geographical source of honeys

In the present research we optimised an extraction procedure for the flavonoid aglycones: myricetin, quercetin and luteolin from honeys (as natural biological matrices), based on Amberlite XAD-4 resin followed by HPLC quantification. In addition, honeys from three geographical regions of Argentina were analysed with regard to the contents of these flavonoids. The extraction procedure was optimised for XAD-4 resin considering: resin/honey ratio, elution volume to desorb flavonoids and colour intensity of honeys. Differences in flavonoid recoveries were observed depending on the colour intensity. The flavonoid aglycones contents, in accordance with differences in geochemical characteristics and typical vegetation, varied with the geographical origin of honeys. The results obtained allowed us to consider these three flavonoids as chemical markers for the phytogeographical origin of honeys. In the case of monofloral honeys, the contribution of each one of the flavonoids was associated with the presence of a dominant pollen kind in these samples.

A model for predicting geographic origin of honey from the same floral source

A model for predicting geographic origin of honey from the same floral source

Authentication of the Botanical and Geographical Origin of Honey by Front-Face Fluorescence Spectroscopy

Front-face fluorescence spectroscopy, directly applied on honey samples, was used for the authentication of 11 unifloral and polyfloral honey types (n = 371 samples) previously classified using traditional methods such as chemical, pollen, and sensory analysis. Excitation spectra (220-400 nm) were recorded with the emission measured at 420 nm. In addition, emission spectra were recorded between 290 and 500 nm (excitation at 270 nm) as well as between 330 and 550 nm (excitation at 310 nm). A total of four different spectral data sets were considered for data analysis. Chemometric evaluation of the spectra included principal component analysis and linear discriminant analysis; the error rates of the discriminant models were calculated by using Bayes' theorem. They ranged from <0.1% (polyfloral and chestnut honeys) to 9.9% (fir honeydew honey) by using single spectral data sets and from <0.1% (metcalfa honeydew, polyfloral, and chestnut honeys) to 7.5% (lime honey) by combining two data sets. This study indicates that front-face fluorescence spectroscopy is a promising technique for the authentication of the botanical origin of honey and may also be useful for the determination of the geographical origin within the same unifloral honey type.

Authentication of the Botanical and Geographical Origin of Honey by Mid-Infrared Spectroscopy

The potential of Fourier transform mid-infrared spectroscopy (FT-MIR) using an attenuated total reflectance (ATR) cell was evaluated for the authentication of 11 unifloral (acacia, alpine rose, chestnut, dandelion, heather, lime, rape, fir honeydew, metcalfa honeydew, oak honeydew) and polyfloral honey types (n = 411 samples) previously classified with traditional methods such as chemical, pollen, and sensory analysis. Chemometric evaluation of the spectra was carried out by applying principal component analysis and linear discriminant analysis, the error rates of the discriminant models being calculated by using Bayes' theorem. The error rates ranged from <0.1% (polyfloral and heather honeys as well as honeydew honeys from metcalfa, oak, and fir) to 8.3% (alpine rose honey) in both jackknife classification and validation, depending on the honey type considered. This study indicates that ATR-MIR spectroscopy is a valuable tool for the authentication of the botanical origin and quality control and may also be useful for the determination of the geographical origin of honey.