Honeys Of Different Floral Origins Research Articles

Development of a LC-QTOF-MS based dilute-and-shoot approach for the botanical discrimination of honeys

Honeys of particular botanical origins can be associated with premium market prices, a trait which also makes them susceptible to fraud. Currently available authenticity testing methods for botanical classification of honeys are either time-consuming or only target a few “known” types of markers. Simple and effective methods are therefore needed to monitor and guarantee the authenticity of honey. In this study, a ‘dilute-and-shoot’ approach using liquid chromatography (LC) coupled to quadrupole time-of-flight-mass spectrometry (QTOF-MS) was applied to the non-targeted fingerprinting of honeys of different floral origin (buckwheat, clover and blueberry). This work investigated for the first time the impact of different instrumental conditions such as the column type, the mobile phase composition, the chromatographic gradient, and the MS fragmentor voltage (in-source collision-induced dissociation) on the botanical classification of honeys as well as the data quality. Results indicated that the data sets obtained for the various LC-QTOF-MS conditions tested were all suitable to discriminate the three honeys of different floral origin regardless of the mathematical model applied (random forest, partial least squares-discriminant analysis, soft independent modelling by class analogy and linear discriminant analysis). The present study investigated different LC-QTOF-MS conditions in a “dilute and shoot” method for honey analysis, in order to establish a relatively fast, simple and reliable analytical method to record the chemical fingerprints of honey. This approach is suitable for marker discovery and will be used for the future development of advanced predictive models for honey botanical origin.

Automatic NMR-based protocol for assessment of honey authenticity

1H NMR analysis of organic extracts of honey is a powerful technique to confirm its botanical origin, thanks to the presence of signals that are specific to each floral typology. Similarly, signals from bee metabolites provide an important tool to verify honey entomological origin. Here, we present a method for honey screening that does not require any detailed analysis of the NMR spectrum for the detection and quantification of such markers. Our approach is based on the measurement of two spectral parameters, named entomological factor (EF) and aromatic factor (AF), calculated by integration of well-defined regions of the NMR spectrum. The values of EF and AF can reveal direct or indirect dilution of honey with sugar syrups. This method was tested on honeys of different floral origins and could identify all adulterated samples previously recognized by official techniques. Notably, several samples found compliant by official methods were proven non-genuine by the proposed approach.

Antimicrobial Properties, Functional Characterisation and Application of Fructobacillus fructosus and Lactiplantibacillus plantarum Isolated from Artisanal Honey.

Honey is a valuable reservoir of lactic acid bacteria (LAB) and, particularly, of fructophilic LAB (FLAB), a relatively novel subgroup of LAB whose functional potential for human and food application has yet to be explored. In this study, FLAB and LAB strains have been isolated from honeys of different floral origins and selected for their broad antimicrobial activity against typical foodborne pathogenic bacteria and spoilage filamentous fungi. The best candidates, two strains belonging to the species Lactiplantibacillus plantarum and Fructobacillus fructosus, were submitted to partial characterisation of their cell free supernatants (CFS) in order to identify the secreted metabolites with antimicrobial activity. Besides, these strains were examined to assess some major functional features, including in vitro tolerance to the oro-gastrointestinal conditions, potential cytotoxicity against HT-29 cells, adhesion to human enterocyte-like cells and capability to stimulate macrophages. Moreover, when the tested strains were applied on table grapes artificially contaminated with pathogenic bacteria or filamentous fungi, they showed a good ability to antagonise the growth of undesired microbes, as well as to survive on the fruit surface at a concentration that is recommended to develop a probiotic effect. In conclusion, both LAB and FLAB honey-isolated strains characterised in this work exhibit functional properties that validate their potential use as biocontrol agents and for the design of novel functional foods. We reported antimicrobial activity, cytotoxic evaluation, probiotic properties and direct food application of a F. fructosus strain, improving the knowledge of this species, in particular, and on FLAB, more generally.

Determination of Floral Origin Markers of Latvian Honey by Using IRMS, UHPLC-HRMS, and 1H-NMR.

The economic significance of honey production is crucial; therefore, modern and efficient methods of authentication are needed. During the last decade, various data processing methods and a combination of several instrumental methods have been increasingly used in food analysis. In this study, the chemical composition of monofloral buckwheat (Fagopyrum esculentum), clover (Trifolium repens), heather (Calluna vulgaris), linden (Tilia cordata), rapeseed (Brassica napus), willow (Salix cinerea), and polyfloral honey samples of Latvian origin were investigated using several instrumental analysis methods. The data from light stable isotope ratio mass spectrometry (IRMS), ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS), and nuclear magnetic resonance (NMR) analysis methods were used in combination with multivariate analysis to characterize honey samples originating from Latvia. Results were processed using the principal component analysis (PCA) to study the potential possibilities of evaluating the differences between honey of different floral origins. The results indicate the possibility of strong differentiation of heather and buckwheat honeys, and minor differentiation of linden honey from polyfloral honey types. The main indicators include depleted δ15N values for heather honey protein, elevated concentration levels of rutin for buckwheat honey, and qualitative presence of specific biomarkers within NMR for linden honey.

Electronic Nose for the Classification of Honeys of Different Floral Origins

The electronic nose contributes, together with other chemical analyses, to identify botanical and geographical origin of honey. Two different honey samples were analysed: Italian Sainfoin (Sulla coronaria (L.) Medik.) and Eucalyptus (Eucalyptus camaldulensis Dehnh.). Aromatic profiles were evaluated using an electronic nose with a sensor array made up of 10 metal oxide semiconductor sensors (MOS). The maximum value for each sensor was used to plot data on a radar graph and for Principal Component Analysis (PCA). The PCA plot revealed a clear separation of samples.A complementary analysis of the volatile species in honeys was carried out using the head space solid phase microextraction coupled to gas chromatography and mass spectroscopy (HS-SPME-GC-MS) and the chemical profile of each sample was derived. Chemical data were compared to the results obtained with the electronic nose and confirmed the assignment of the different unifloral samples.The results showed that the electronic nose, combined with chemical identification of the volatile species, allows to classify and discriminate the different types of honey and to assign them to groups that have similar taste and aroma characteristics.

Antioxidant HPTLC-DPPH Fingerprinting of Honeys and Tracking of Antioxidant Constituents Upon Thermal Exposure.

The use of High-Performance Thin-Layer Chromatography (HPTLC) coupled with the use of DPPH* (2,2-diphenyl-1-picrylhydrazyl) as a derivatisation reagent is a novel approach to the analysis of antioxidant activity of honeys. The method facilitates the visualisation of individual constituents that contribute to the overall antioxidant activity of the honey, even if they are not yet chemically identified, and allows for the quantification of their antioxidant activity as gallic acid equivalents. The method supports a more in-depth study of the antioxidant activity of honey as it allows for a comparative analysis of the antioxidant fingerprints of honeys of different floral origin and is able to capture differences in their individual bioactive constituents. Further, it supports the tracking of changes in antioxidant activity of individual honey constituents over time upon exposure to different temperature conditions, which demonstrates the potential value of the method for in-process quality control.

Capillary liquid chromatography as an effective method for the determination of seven neonicotinoid residues in honey samples.

A new analytical method based on capillary liquid chromatography with diode array detection has been developed for the simultaneous quantification of seven neonicotinoid insecticides commercially available (imidacloprid, thiacloprid, clothianidin, thiamethoxam, acetamiprid, nitenpyram, and dinotefuran) in honey samples. The separation was achieved in a Zorbax XDB-C18 column (150×0.5mm id, 5μm), with a mobile phase consisting of ultrapure water (solvent A) and acetonitrile (solvent B) at a flow rate of 10 μL/min. Capillary column was thermostated at 25°C during the analysis and 254 or 270nm was established as detection wavelength, depending on the analyte. Furthermore, full loop injection mode (8 μL) was selected, using water as injection solvent. Finally, the optimized method was applied to the analysis of neonicotinoid residues in honey of different floral origins using dispersive liquid-liquid microextraction as sample treatment. Variables affecting the extraction efficiency were optimized, choosing methanol and dichloromethane as dispersive and extraction solvents, respectively. The method was characterized in terms of linearity ( ≥ 0.9948), repeatability, reproducibility (relative standard deviation below 4.5 and 6.3% respectively), and recoveries (≥80.5%). Detection and quantification limits were lower than 6.6 and 22.0μg/kg for the studied analytes, respectively.

Insight into the sensing mechanism of an impedance based electronic tongue for honey botanic origin discrimination

An impedance based electronic tongue was developed and used to discriminate honey of different botanic origin. The e-tongue presented here is based on the small-signal frequency response of the electrical double-layer established between the honey solution and an array of four different sensing units composed by gold, carbon, indium-tin-oxide, and doped silicon. The ability of the e-tongue to discriminate honey of different floral origins was demonstrated by distinguishing honey from Bupleurum and Lavandula pollen prevalence. The honey fingerprint obtained with the e-tongue was validated by parallel melissopalenogical analysis and physico-chemical methods. It is demonstrated that the e-tongue is very sensitive to changes on the honey electrical conductivity. Small differences in electrical conductivity are introduced by the presence of ionisable organic acids and mineral salts. Moreover, we propose that the sensitivity of the tongue to changes in electrical conductivity can be explored to probe other complex liquid substances.

Research on Honey Crystalization

Crystallization of honey is a natural process and guarantee of authenticity. The aim of the study is to evaluate the influence of physico-chemical parameters on the process of crystallization and on crystal size. The interest in studying the factors influencing the crystallization process is due to the fact that most consumers, especially children, are reserved for the purchase and consumption of a crystallized honey, the commercial aspect being very important to them. Three samples of honey of different floral origins were used for the physico-chemical and microscopic analysis. The analyzes were carried out throughout 30 days every sample in triplicate. In terms of physicochemical following parameters were analyzed: acidity, diastase index, hydroximethylfurfural, humidity, invert sugar, glucose, fructose, fructose / glucose ratio and the microscopic analyze of crystals size. The parameter values resulting from the research study are in accordance with the legislation in force. Statistical analysis of experimental data highlights the influence of ratio fructose / glucose and humidity on the honey crystallization.

Element content of Yemeni honeys as a long-time marker to ascertain honey botanical origin and quality

This work was aimed at studying variations in the element content of five famous Yemeni honeys of different floral origin. For this purpose, samples of honey were collected over three years from four mono-floral and one multi-floral honey. Element levels were determined by ICP-AES. Results show a highly reproducible level of element for each honey type and a significant change in element content in honey as a function of the floral source. In addition to demonstrating the impact of the floral origin on Yemeni-honey mineral content, our compiled values will be highly useful to ascertain honey quality once Yemen will return to less-trouble times.

Authentication of honeys of different floral origins via high-performance thin-layer chromatographic fingerprinting

This paper explores the high-performance thin-layer chromatographic (HPTLC) fingerprinting of non-sugar constituents for the authentication of honeys using highly antibacterial Jarrah (Eucalyptus marginata) and Marri (Corymbia calophylla) honeys sourced from Western Australia, different Leptospermum-derived Manuka honeys, and a typical table honey from an undisclosed floral source as test samples. As is demonstrated in this study, using HPTLC fingerprinting, it is possible to define differences in botanical origin as the honey fingerprints exhibit a unique profile of bands (i.e., Rf values, color) and peak profiles (i.e., Rf and peak intensity values, peak intensity ratios) that differ distinctly from each other. The identification of patterns of common bands among honeys derived from the same floral source as authentication tool is possible. Further, slight differences among honeys from the same botanical origin might be due to age, processing, or regional factors. The HPTLC analysis of two differently a...

Antimicrobial Activity of Some Italian Honeys Against Pathogenic Bacteria

Some Italian honeys of different floral origin (acacia, orange, chestnut, coriander, eucalyptus, lime, wildflower) and one honeydew honey were investigated for their potential as natural antimicrobials against pathogens commonly associated with wound or burn infections. S. aureus, S. epidermidis, E. coli, P. aeruginosa and P. mirabilis were used as test microorganisms. The honeys examined showed moderate to high antibacterial activity, with honeydew, eucalyptus and wildflower honeys being the most effective. MIC values obtained by the agar incorporation method were in the range of 5–20% (v/v). Gram-positive bacteria were more susceptible to the inhibitory action of honey, probably because of their larger outer-membrane permeability to exogenous substances. Overall, the results suggest that some of the honeys considered here might have excellent potential for use in antimicrobial formulations for topical applications.

Rheological and Thermal Properties of Selected Brazilian Honeys from Various Floral Origins

AbstractThe rheological and thermal properties of honeys have a practical importance for beekeepers and industries, as their determination allows their proper processing and quality control. However, few studies have been carried out in this area with Brazilian honeys. Therefore, physicochemical, rheological and thermal properties of 40 Brazilian honeys of different floral origins were determined in this study. All the physicochemical properties indicated that the analyzed honey samples met the criteria for honeys established by Codex Alimentarius. The honeys showed non‐Newtonian behavior from 10C to 15C and Newtonian behavior from 20C to 30C with the influence of temperature on viscosity and on the viscous modulus (G″) described by the Arrhenius models. Oscillatory rheological data revealed a liquid‐like behavior (G″> elastic modulus (G′)) of the honeys. The glass transition temperature (Tg) of the honeys varied between −46.7C and −43.7C. By the principal component analysis (PCA), the first component explained 70.0% of the variation of the data, forming two groups described by moisture content, aw, viscosity (10C to 30C), G″ and Tg. This analysis confirms the important influence of the moisture content and of aw in the rheological and thermal properties of honeys and provide useful information for the industrialization of honey and honey‐based products.Practical ApplicationDetermining the honey rheological and thermal properties allows its proper processing and quality control, preventing the waste of economic resources. Conclusions for beekeepers and industries are: the honey physicochemical properties are in conformity with the Brazilian legislation and the Codex Alimentarius, which could be used by consumers and the food industry; rheological and thermal properties are inversely correlated with the moisture content and with aw, and could be used to distinguish Brazilian honeys; Brazilian honeys behave as diluted materials, and their viscosity is temperature‐ and floral origin‐dependent. Determining their viscosity helps in the performance, sizing and selection of equipment such as pumps, mixers, filters, centrifuges and heat exchangers; temperature fluctuations induce physical and chemical alterations in the honey, and temperature control during its processing and storage is important for maintaining its quality. All of these parameters provide useful information for the development of new products, optimization of industrial processes and control of quality and authenticity of honeys.

Potentiation of Bioactive Compounds and Antioxidant Activity in Artisanal Honeys Using Specific Heat Treatments

The effect of temperature on the phenol content, flavonoids content, hydroxymethylfurfural (HMF) and antioxidant activity (DPPH and ABTS) in five artisanal honeys of different floral origins was investigated. The total phenol and total flavonoid content showed either linear or quadratic curves (P < 0.05) for heat treatment according to the origin of the honey. For HMF, all of the honeys displayed linear behavior with the heat treatments. All of the honeys had linear responses to temperature (P < 0.05) and antioxidant activity as measured by DPPH. The antioxidant activity measured as the ABTS showed either a linear or quadratic (P < 0.05) curve response depending on the floral origin. The profile of the correlation coefficients between the bioactive compounds (phenols, flavonoids and HMF) and antioxidant activity (DPPH and ABTS) was different for each type of honey. It is possible to enhance the antioxidant activity of artisanal honeys with a specific heat treatment. Practical Applications Currently, nutraceuticals use honey for its antioxidant activity. It is important to preserve and improve these properties for the consumer during the processing of honey. In this study, it was found that each honey should be heat treated specifically because each honey has different bioactive compounds according to its floral origin. For some honeys, the thermal behavior of the bioactive compounds and the antioxidant activity was quadratic, with the greatest activity at 70C, whereas for other honeys, the behavior was linear, with the highest bioactive compounds and antioxidant activity at 80C. To enhance the bioactive compounds and antioxidant activity of artisanal honeys, each honey should be treated at a different temperature depending on their linear or quadratic behavior.

Discrimination of honey of different floral origins by a combination of various chemical parameters

Honey is a high value food commodity with recognized nutraceutical properties. A primary driver of the value of honey is its floral origin. The feasibility of applying multivariate data analysis to various chemical parameters for the discrimination of honeys was explored. This approach was applied to four authentic honeys with different floral origins (rata, kamahi, clover and manuka) obtained from producers in New Zealand. Results from elemental profiling, stable isotope analysis, metabolomics (UPLC-QToF MS), and NIR, FT-IR, and Raman spectroscopic fingerprinting were analyzed. Orthogonal partial least square discriminant analysis (OPLS-DA) was used to determine which technique or combination of techniques provided the best classification and prediction abilities. Good prediction values were achieved using metabolite data (for all four honeys, Q2=0.52; for manuka and clover, Q2=0.76) and the trace element/isotopic data (for manuka and clover, Q2=0.65), while the other chemical parameters showed promise when combined (for manuka and clover, Q2=0.43).

Tracing floral and geographical origins of honeys by potentiometric and voltammetric electronic tongue

A potentiometric electronic tongue (PE-tongue) and a voltammetric electronic tongue (VE-tongue) were used as rapid techniques to classify and predict the honey samples from different floral and geographical origins. The PE-tongue, which was named α-ASTREE, was developed by Alpha M.O.S. (Toulouse, France), and it comprises seven potentiometric chemical sensors. The VE-tongue was self-developed at Zhejiang University and comprises six metallic working sensors. Four types of honey of different floral origins (acacia, buckwheat, data, and motherwort) and four types of acacia honey of different geographical origins were classified by both multisensor systems. Multivariate statistical data analysis techniques such as principal component analysis (PCA) and discriminant function analysis (DFA) were used to classify the honey samples. Both types of electronic tongue have good potential to classify the honey samples, and the positions of the data point for the samples in the PCA score plots based on the VE-tongue were much more closely grouped. Three regression modes, principal component regression (PCR), partial least squares regression (PLSR), and least squared-support vector machines (LS-SVM), were applied for category forecasting. These regression models exhibited a clear indication of the prediction ability of the two types of electronic tongue, and a positive trend in the prediction of the floral and geographical origin of honey was found. Moreover, the performance of these regression models for predicting the four types of honey of different geographical origins by the VE-tongue is very stable.

Determination of Flavonoids, Phenolic Acids and Abscisic Acid in Honeys of Different Floral Origins by HPLC

Flavonoids(rutin,myricetin,quercetin,naringenin,luteolin,keampferol and apigenin),phenolic acids(gallic acid,catechin,caffeic acid,α-catechin,p-coumaric acid,ferulic acid and 3,4-dimethoxycinnamic acid) and abscisic acid in honeys of different floral origins(lichee honey,longan honey,loquat honey,linden honey,date honey,lenourus honey,osmanthus honey,and Chinese milk vetch honey) were analyzed by HPLC-PDA.There were significant differences in the contents of abscisic acid among different samples.Abscisic acid content was ranged from 16.4 μg/100 g(osmanthus honey) to 1321.9 μg/100 g(lichee honey).Total phenolic contents of eight honey samples varied from 325.3 to 2260.8 μg/100 g honey.Among them,keampferol was be detected only in longan honey,loquat honey,lichee honey,date honey and Chinese milk vetch honey.Lichee honey contained the highest amount of ferulic acid,myricetin and quercetin.However,α-catechin was the main component in loquat honey.Longan honey contained a considerable amount of 3,4-dimethoxycinnamic acid,p-coumaric acid and luteolin.These results show that the profile of flavonoids,phenolic acids and abscisic acid could be used for authenticating the floral origin of a honey sample.

Antiproliferative and apoptotic effects of spanish honeys

Background:Current evidence supports that consumption of polyphenols has beneficial effects against numerous diseases mostly associated with their antioxidant activity. Honey is a good source of antioxidants since it contains a great variety of phenolic compounds.Objective:The main objective of this work was to investigate the antiproliferative and apoptotic effects of three crude commercial honeys of different floral origin (heather, rosemary and polyfloral honey) from Madrid Autonomic Community (Spain) as well as of an artificial honey in human peripheral blood promyelocytic leukemia cells (HL-60).Material and Methods:HL-60 cells were cultured in the presence of honeys at various concentrations for up to 72 hours and the percentage of cell viability was evaluated by MTT assay. Apoptotic cells were identified by chromatin condensation and flow cytometry analysis. ROS production was determined using 2´,7´-dichlorodihydrofluorescein diacetate (H2DCFDA).Results:The three types of crude commercial honey induced apoptosis in a concentration and time dependent-manner. In addition, honeys with the higher phenolic content, heather and polyfloral, were the most effective to induce apoptosis in HL-60 cells. However, honeys did not generate reactive oxygen species (ROS) and N-acetyl-L-cysteine (NAC) could not block honeys-induced apoptosis in HL-60 cells.Conclusion:These data support that honeys induced apoptosis in HL-60 cells through a ROS-independent cell death pathway. Moreover, our findings indicate that the antiproliferative and apoptotic effects of honey varied according to the floral origin and the phenolic content.

Classification of Floral Origins of Honey by NIR and Chemometrics

Near-infrared (NIR) spectroscopy combined with chemometrics methods has been investigated to discriminate type of honey. 147 NIR spectra of six floral origins of honey samples were collected within 4000~10000cm-1 spectral region. Spectral data were compressed using partial least squares (PLS). Back propagation neural networks (BPNN) models were constructed to distinguish the type of honey. Six spectral data pretreatments including first derivative, first derivatives followed by mean centering(MC), second derivatives, Savitzky-Golay smoothing, standard normal variate transformation (SNV) and multiplicative scattering correction (MSC) were compared to establish the optimal models for honey discrimination. Savitzky-Golay smoothing proved more effective than the other data pretreatments. BPNN models were developed within the full spectral region, 5303～6591cm-1 and 7012～10001cm-1, respectively. Results have shown that the highest(100%) classification rate was achieved within 5303～6591cm-1 wave range. Our results indicated that NIR spectroscopy with chemometrics techniques can be applied to classify rapidly honeys of different floral origin.

A Biomimetic Sensor for the Classification of Honeys of Different Floral Origin and the Detection of Adulteration

The major compounds in honey are carbohydrates such as monosaccharides and disaccharides. The same compounds are found in cane-sugar concentrates. Unfortunately when sugar concentrate is added to honey, laboratory assessments are found to be ineffective in detecting this adulteration. Unlike tracing heavy metals in honey, sugar adulterated honey is much trickier and harder to detect, and traditionally it has been very challenging to come up with a suitable method to prove the presence of adulterants in honey products. This paper proposes a combination of array sensing and multi-modality sensor fusion that can effectively discriminate the samples not only based on the compounds present in the sample but also mimic the way humans perceive flavours and aromas. Conversely, analytical instruments are based on chemical separations which may alter the properties of the volatiles or flavours of a particular honey. The present work is focused on classifying 18 samples of different honeys, sugar syrups and adulterated samples using data fusion of electronic nose (e-nose) and electronic tongue (e-tongue) measurements. Each group of samples was evaluated separately by the e-nose and e-tongue. Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were able to separately discriminate monofloral honey from sugar syrup, and polyfloral honey from sugar and adulterated samples using the e-nose and e-tongue. The e-nose was observed to give better separation compared to e-tongue assessment, particularly when LDA was applied. However, when all samples were combined in one classification analysis, neither PCA nor LDA were able to discriminate between honeys of different floral origins, sugar syrup and adulterated samples. By applying a sensor fusion technique, the classification for the 18 different samples was improved. Significant improvement was observed using PCA, while LDA not only improved the discrimination but also gave better classification. An improvement in performance was also observed using a Probabilistic Neural Network classifier when the e-nose and e-tongue data were fused.