Quality Evaluation of Light- and Dark-Colored Hungarian Honeys,Focusing on Botanical Origin,Antioxidant Capacity and Mineral Content

Melissopalynology, antioxidant capacity and mineral and toxic element contents were analyzed in eight types of Hungarian honeys. Based on color, two groups were distinguished: light honeys comprised acacia, amorpha, phacelia and linden honeys; while dark honeys included sunflower, chestnut, fennel and sage honeys, with 100 to 300 and 700 to 1500 mAU, respectively. The unifloral origin of each sample was supported using pollen analysis. The absorbance of honey correlated positively with antioxidant capacity determined by three different methods (TRC, DPPH, ORAC), and also with mineral content. The exception was the light amber linden honey with significantly higher K content and antiradical activity than other light honeys. The Mn, Zn and Fe contents were the highest in chestnut, sunflower and fennel honeys, respectively. The black meadow sage honey performed best regarding the content of other elements and antioxidant activity. The concentrations of several toxic elements were below the detection limit in the samples, indicating their good quality. The principal component analysis (PCA) revealed correlations between different antioxidant assays and minerals, and furthermore, confirmed the botanical authentication of the honeys based on the studied parameters. To our best knowledge, the present study is the first to provide a complex analysis of quality parameters of eight unifloral Hungarian honeys.     

Mineral content and botanical origin of Spanish honeys

Eleven elements (Zn, P, B, Mn, Mg, Cu, Ca, Ba, Sr, Na and K) were determined by inductively plasma coupled spectrometry in 40 honey samples from different places of Spain and four different botanical origins: Eucalyptus (Eucalyptus sp.), Heather (Erica sp.), Orange-blossom (Citrus sinensis) and Rosemary (Rosmarinus officinalis). K, Ca and P show the higher levels with average concentrations ranged between 434.1-1935 mg kg⁻¹ for K; 42.59-341.0 mg kg⁻¹ for Ca and 51.17-154.3 mg kg⁻¹ for P. Levels of Cu (0.531-2.117 mg kg⁻¹), Ba (0.106-1.264 mg kg⁻¹) and Sr (0.257-1.462 mg kg⁻¹) are the lowest in all honey samples. Zn (1.332-7.825 mg kg⁻¹), Mn (0.133-9.471 mg kg⁻¹), Mg (13.26-74.38 mg kg⁻¹) and Na (11.69-218.5 mg kg⁻¹) concentrations were found strongly dependent on the kind of botanical origin.Results were submitted to pattern recognition procedures, unsupervised methods such as cluster and principal components analysis and supervised learning methods like linear discriminant analysis in order to evaluate the existence of data patterns and the possibility of differentiation of Spanish honeys from different botanical origins according to their mineral content. Cluster analysis shows four clusters corresponding to the four botanical origins of honey and PCA explained 71% of the variance with the first two PC variables. The best-grouped honeys were those from heather; eucalyptus honeys formed a more dispersed group and finally orange-blossom and rosemary honeys formed a less distinguishable group.     

Determination of B-group vitamins in Turkish honey using ultra-performance liquid chromatography with electrospray ionization coupled to tandem mass spectrometry

A rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry method with electrospray ionization (UPLC–ESI–MS/MS) for analysis of B-group vitamins in honey has been presented. Aim of this study is the characterization of different types of Turkish honeys according to B-group vitamins. Vitamins were determined in 17 different types of Turkish honey samples by UPLC–ESI–MS/MS. Heather honey samples were distinguished among the studied honeys with the richest vitamin content with 286.10?mg/kg, and it is followed by sunflower honey and thyme honey with the total vitamin contents of 206.01 and 163.27?mg/kg, respectively. The presence of vitamin B₁ (thiamine), vitamin B₂ (riboflavin), vitamin B₃ (nicotinamide, B₃N and nicotinic acid, B₃H), vitamin B₆ (pyridoxine), and vitamin B₉ (folic acid) was detected in all the honey samples analyzed. Moreover, vitamin B₅ (pantothenic acid) was observed in most of them. Vitamin B₁₂ (cyanocobalamin) and vitamin B₇ (biotine) were not detected in the studied honey samples. Turkish honey samples showed efficacious vitamin content for the consumers.     

Multielemental characterization of honey using inductively coupled plasma mass spectrometry fused with chemometrics

Honey is considered a desirable ingredient in a range of different foodstuffs because of its nutrient and therapeutic effect. The honey characteristics mainly depend on the type of vegetation visited by the bees and the climatic conditions in which the plants are growing. Therefore, the purity, floral and geographical origin and authenticity are important factors influencing the overall perception of honey and honey‐based products in terms of quality and price. An important parameter in this picture is the elemental composition of honey because it can be linked with the floral type of honey, floral plant density and the botanical origin of nectar and pollens. In this work, the concentration range variation of 18 elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Mg, Mn, Na, Ni, K, Pb, Sr, Ti, V and Zn) was investigated in four varieties of honey (linden, acacia, rape, and sunflower) originating from Romania, because the elemental profile of honey may give important information to differentiate its geographical and varietal origin for authenticity purpose. All the determinations were carried out by inductively coupled plasma quadrupole mass spectrometry (ICP‐Q‐MS). The most abundant minerals decreased in the following order: K > Ca > Mg > Na, having the mean values of 248.70, 59.97, 20.54 and 11.92 mg kg^?1, respectively. The mineral content marks the differences in honey samples from different botanical origin and can be used as a tool for authentication purposes and also extends its applicability to assess the traceability of honey. Analysis of variance showed the preliminary relationships between the elements and samples. Further, the discrimination between different studied honey samples was achieved by principal component analysis (PCA). The multivariate analysis of the data allowed us to separate the honey samples into distinct groups according to their macroelement and microelement composition, emphasizing the origin of variation of element concentrations by honey type. Therefore, this approach might be potentially useful for the control of honey quality, origin or authenticity, and even to use the honey as environmental tracer.     

基于超高效液相色谱-四极杆飞行时间质谱的非靶向代谢组学用于不同来源单花蜜的差异分析

不同的蜜源植物具有结构多样的次生代谢产物。该研究以8种不同蜜源单花蜜(洋槐蜜、枣花蜜、荆条蜜、椴树蜜、荞麦蜜、麦卢卡蜜、枸杞蜜、益母草蜜)为研究对象,建立了基于超高效液相色谱-四极杆飞行时间质谱技术(UPLC-Q-TOF-MS^E)的非靶向代谢组学方法,考察了不同蜜源中次生代谢产物的差异。该研究采用固相萃取前处理方法和UPLC-Q-TOF-MS^E方法,获得不同蜜源单花蜜的植物代谢组信息,并构建了多变量统计分析模型,对不同来源的单花蜜进行模式识别和差异分析,发现洋槐蜜、枣花蜜、荆条蜜、椴树蜜、荞麦蜜、麦卢卡蜜相互间存在不同程度的显著差异。结合模型的变量重要性投影、方差分析与最大差异倍数值,根据精确前体离子和碎片离子质量信息检索Chemspider、HMDB数据库,该研究筛选并鉴定出32个代谢差异化合物,其中黄酮类化合物18个、酚酸类化合物7个、苯苷与萜苷类化合物6个、甾体类化合物1个;研究发现麦卢卡蜜和荞麦蜜以黄酮类化合物为主要差异代谢物,荆条蜜中酚酸类化合物为特征性表达,苯苷与萜苷类化合物主要为椴树蜜的特征代谢物。该研究从植物代谢组学角度初步揭示了不同单花蜜的代谢产物差异性以及特征化合物,为基于化学分析技术的蜂蜜溯源识别与质量评价提供了有效的研究策略。     

Bioactive Molecules for Discriminating Robinia and Helianthus Honey: High-Performance Liquid Chromatography–Electron Spray Ionization–Mass Spectrometry Polyphenolic Profile and Physicochemical Determinations

Bioactive molecules from the class of polyphenols are secondary metabolites from plants. They are present in honey from nectar and pollen of flowers from where honeybees collect the “raw material” to produce honey. Robinia pseudoacacia and Helianthus annuus are important sources of nectar for production of two monofloral honeys with specific characteristics and important biological activity. A high-performance liquid chromatography–electro spray ionization–mass spectrometry (HPLC–ESI–MS) separation method was used to determine polyphenolic profile from the two types of Romanian unifloral honeys. Robinia and Helianthus honey showed a common flavonoid profile, where pinobanksin (1.61 and 1.94 mg/kg), pinocembrin (0.97 and 1.78 mg/kg) and chrysin (0.96 and 1.08 mg/kg) were identified in both honey types; a characteristic flavonoid profile in which acacetin (1.20 mg/kg), specific only for Robinia honey, was shown; and quercetin (1.85 mg/kg), luteolin (21.03 mg/kg), kaempferol (0.96 mg/kg) and galangin (1.89 mg/kg), specific for Helianthus honey, were shown. In addition, different phenolic acids were found in Robinia and Helianthus honey, while abscisic acid was found only in Robinia honey. Abscisic acid was correlated with geographical location; the samples collected from the south part of Romania had higher amounts, due to climatic conditions. Acacetin was proposed as a biochemical marker for Romanian Robinia honey and quercetin for Helianthus honey.     

Honey Phenolic Compound Profiling and Authenticity Assessment Using HRMS Targeted and Untargeted Metabolomics

Honey consumption is attributed to potentially advantageous effects on human health due to its antioxidant capacity as well as anti-inflammatory and antimicrobial activity, which are mainly related to phenolic compound content. Phenolic compounds are secondary metabolites of plants, and their content in honey is primarily affected by the botanical and geographical origin. In this study, a high-resolution mass spectrometry (HRMS) method was applied to determine the phenolic profile of various honey matrices and investigate authenticity markers. A fruitful sample set was collected, including honey from 10 different botanical sources (n = 51) originating from Greece and Poland. Generic liquid–liquid extraction using ethyl acetate as the extractant was used to apply targeted and non-targeted workflows simultaneously. The method was fully validated according to the Eurachem guidelines, and it demonstrated high accuracy, precision, and sensitivity resulting in the detection of 11 target analytes in the samples. Suspect screening identified 16 bioactive compounds in at least one sample, with abscisic acid isomers being the most abundant in arbutus honey. Importantly, 10 markers related to honey geographical origin were revealed through non-targeted screening and the application of advanced chemometric tools. In conclusion, authenticity markers and discrimination patterns were emerged using targeted and non-targeted workflows, indicating the impact of this study on food authenticity and metabolomic fields.     

Determination of the Chemical Structure of Linden Ether

The chemical structure of the novel monoterpene 1 , named ‘linden ether’ and isolated from linden honey and the blossoms of lime tree (Tilia cordata), was studied by two-dimensional NMR spectroscopy, by high-resolution MS as well as by hydrogenation experiments and by GC on a chiral phase. Thus, linden ether was identified as a racemic mixture, i.e. (7aRS)-2, 4, 5, 7a-tetrahydro-3, 6-dimethylbenzofuran.     

Origin Identification of Hungarian Honey Using Melissopalynology,Physicochemical Analysis,and Near Infrared Spectroscopy

The objective of the study was to check the authenticity of Hungarian honey using physicochemical analysis, near infrared spectroscopy, and melissopalynology. In the study, 87 samples from different botanical origins such as acacia, bastard indigo, rape, sunflower, linden, honeydew, milkweed, and sweet chestnut were collected. The samples were analyzed by physicochemical methods (pH, electrical conductivity, and moisture), melissopalynology (300 pollen grains counted), and near infrared spectroscopy (NIRS:740–1700 nm). During the evaluation of the data PCA-LDA models were built for the classification of different botanical and geographical origins, using the methods separately, and in combination (low-level data fusion). PC number optimization and external validation were applied for all the models. Botanical origin classification models were >90% and >55% accurate in the case of the pollen and NIR methods. Improved results were obtained with the combination of the physicochemical, melissopalynology, and NIRS techniques, which provided >99% and >81% accuracy for botanical and geographical origin classification models, respectively. The combination of these methods could be a promising tool for origin identification of honey.     

The Use of UV Spectroscopy and SIMCA for the Authentication of Indonesian Honeys According to Botanical,Entomological and Geographical Origins

As a functional food, honey is a food product that is exposed to the risk of food fraud. To mitigate this, the establishment of an authentication system for honey is very important in order to protect both producers and consumers from possible economic losses. This research presents a simple analytical method for the authentication and classification of Indonesian honeys according to their botanical, entomological, and geographical origins using ultraviolet (UV) spectroscopy and SIMCA (soft independent modeling of class analogy). The spectral data of a total of 1040 samples, representing six types of Indonesian honey of different botanical, entomological, and geographical origins, were acquired using a benchtop UV-visible spectrometer (190–400 nm). Three different pre-processing algorithms were simultaneously evaluated; namely an 11-point moving average smoothing, mean normalization, and Savitzky–Golay first derivative with 11 points and second-order polynomial fitting (ordo 2), in order to improve the original spectral data. Chemometrics methods, including exploratory analysis of PCA and SIMCA classification method, was used to classify the honey samples. A clear separation of the six different Indonesian honeys, based on botanical, entomological, and geographical origins, was obtained using PCA calculated from pre-processed spectra from 250–400 nm. The SIMCA classification method provided satisfactory results in classifying honey samples according to their botanical, entomological, and geographical origins and achieved 100% accuracy, sensitivity, and specificity. Several wavelengths were identified (266, 270, 280, 290, 300, 335, and 360 nm) as the most sensitive for discriminating between the different Indonesian honey samples.     

Reinvestigation of carvotanacetone after 100 years along with minor terpenoid constituents of Blumea malcolmii Hook. F. essential oil

Reinvestigation of essential oil constituents of Blumea malcolmii Hook. F. (Asteraceae) was carried out after 100 years using gas chromatography equipped with flame ionisation detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Eighteen constituents, representing 99.2% of the total oil, were identified. The major compound was identified by GC/MS and NMR (¹H and ¹³C) as carvotanacetone (92.1%). The minor compounds of essential oil have also been identified for the first time in B. malcolmii. The oil was found to be rich in oxygenated monoterpene-type constituents (95.0%).     

13C, 15N and 113Cd NMR and Molecular Orbital Studies of Novel Bile Acid N-(2-aminoethyl)amides and Their Cd2+-complexes

Lithocholic acid N-(2-aminoethyl)amide (1) and deoxycholic acid N-(2-aminoethyl)amide(2) have been prepared and characterized by¹H, ¹³C and ¹⁵N NMR. The accurate molecular masses of 1 and 2 have been determined by ESI MS. The formation of the Cd²⁺-complexes (1+Cd and 2+Cd) in CD₃OD solution have been detected by ¹H,¹³C, ¹⁵N and ¹¹³Cd NMR. The ¹³C NMR chemical shift assignments of 1 and 2 and their Cd²⁺-complexes are based on DEPT-135 and z-GS ¹H,¹³C HMQC experiments as well as comparison with the assignments of the related structures. The ¹⁵N NMR chemical shiftassignments of the ligands and theirCd²⁺-complexes are based on z-GS¹H,¹⁵N HMBC experiments. ¹³C NMR chemical shift differences between 1and its 1:1 Cd²⁺-complex based on ab initiocalculations at Hartree-Fock SCI-PCM level using3-21G(d) basis set are in agreement with theexperimental shift changes observed onCd²⁺-complexation.     

Synthesis and Hydrolysis of Hybridized Silicon Alkoxide: Si(OEt)x(OBut)4-x. Part I: Synthesis and Identification of the Si(OEt)x(OBut)4-x

Using silicon tetrachloride (SiCl₄), tert-butanol (t-BuOH), ethanol (EtOH) and NH₃, the hybridized silicon ethoxide 3-tert-butoxide (Si(OEt)_x(OBu^t)_4-x) was synthesized and the configuration of the material was investigated by FT-IR,¹ H and ¹³C NMR and gas chromatogram/mass spectrum (GC/MS) techniques. The results confirm that both the ethoxy and the tert-butoxy groups have been attached to silicon atoms. Furthermore, the alkoxy group types and their relative amounts in the alkoxide were also determined by ¹H and ¹³C NMR and GC/MS.     

The Impact of Grape Varieties to Wine Isotopic Characterization

This paper highlights the results of a study regarding the impact of geo-climatic conditions, the influence of grape varieties, and harvest year on the isotopic characterization of a wine from a specific vineyard area, using stable isotope ratio analysis by continuous flow mass spectrometry CF-IRMS. This analytical technique has made a significant contribution on wine characterization, by proving the botanical and geographical origin of the wine raw material.

A great variability was observed to sap ¹⁸O and ²H isotopic ratios for different types of vine (Vitis vinifera plant) from the studied area, Dealu Mare-Valea Calugareasca, reflecting the significant influence of variety on isotopic features. On the other hand, the comparison of stable isotopic fingerprints for rainfall water and sap revealed a close approximation value for ¹⁸O isotopic ratio, and an insignificant variation coefficient of ¹³C isotopic ratio in wine varieties (about 2.85%).

The results of isotopic characterization for grape vine sap and original wines for different varieties existing in Dealu Mare-Valea Calugareasca vineyard indicates the relevance of meteorological and viticulture parameters like precipitation, date of vintage, and grape cultivar for wine authentication process.     

Characterisation of VOC composition of Slovak monofloral honeys by GC��GC-TOF-MS

Solid phase microextraction (SPME) followed by comprehensive two-dimensional gas chromatography coupled to a time-of-flight mass spectrometer (GC×GC-TOF-MS) was used to characterise volatile organic compounds in honeys of different botanical origins. Rape, sunflower, acacia, lime, raspberry, and phacelia honeys from Slovakia were studied in detail. Up to 900 compounds were detected at the given S/N ratio of 200. The poorest VOC profiles were found for acacia and rape honeys while lime honey showed the richest VOC composition. Approximately 100 compounds were present in all honeys studied, independently of their botanical origin. They belong to various chemical classes (hydrocarbons, alcohols, aldehydes and ketones, terpenes, benzene derivatives, and compounds containing heteroatoms). The compounds found in only one type of honey were also successfully identified.     

Gold(III)pentafluorophenylarylazoimidazole: Synthesis and spectral (H, C, COSY, HMQC NMR) characterisation

Reaction of [Au^III(C₆F₅)₃(tht)] with RaaiR′ in dichloromethane medium leads to [Au^III(C₆F₅)₃ (RaaiR′)] [RaaiR′=p-R-C₆H₄-N=N-C₃H₂-NN-l-R′, (1-3), R = H (a), Me (b), Cl (c) and R′= Me (1), CH₂CH₃ (2), CH₂Ph (3), tht is tetrahydrothiophen]. The nine new complexes are characterised by ES/MS as well as FAB, IR and multinuclear NMR (¹H,¹³C,¹⁹F) spectroscopic studies. In addition to dimensional NMR studies as¹H,¹H COSY and¹H¹³C HMQC permit complete assignment of the complexes in the solution phase.     

Non‐targeted volatile profiles for the classification of the botanical origin of Chinese honey by solid‐phase microextraction and gas chromatography–mass spectrometry combined with chemometrics

A potential method for the discrimination and prediction of honey samples of various botanical origins was developed based on the non‐targeted volatile profiles obtained by solid‐phase microextraction with gas chromatography and mass spectrometry combined with chemometrics. The blind analysis of non‐targeted volatile profiles was carried out using solid‐phase microextraction with gas chromatography and mass spectrometry for 87 authentic honey samples from four botanical origins (acacia, linden, vitex, and rape). The number of variables was reduced from 2734 to 70 by using a series of filters. Based on the optimized 70 variables, 79.12% of the variance was explained by the first four principal components. Partial least squares discriminant analysis, naïve Bayes analysis, and back‐propagation artificial neural network were used to develop the classification and prediction models. The 100% accuracy revealed a perfect classification of the botanical origins. In addition, the reliability and practicability of the models were validated by an independent set of additional 20 authentic honey samples. All 20 samples were accurately classified. The confidence measures indicated that the performance of the naïve Bayes model was better than the other two models. Finally, the characteristic volatile compounds of linden honey were tentatively identified. The proposed method is reliable and accurate for the classification of honey of various botanical origins.     

Chemical Analyses and Antimicrobial Activity of Nine Kinds of Unifloral Chinese Honeys Compared to Manuka Honey (12+ and 20+)

Honey has good antimicrobial properties and can be used for medical treatment. The antimicrobial properties of unifloral honey varieties are different. In this study, we evaluated the antimicrobial and antioxidant activities of nine kinds of Chinese monofloral honeys. In addition, headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) technology was used to detect their volatile components. The relevant results are as follows: 1. The agar diffusion test showed that the diameter of inhibition zone against Staphylococcus aureus of Fennel honey (21.50 ± 0.41 mm), Agastache honey (20.74 ± 0.37 mm), and Pomegranate honey (18.16 ± 0.11 mm) was larger than that of Manuka 12+ honey (14.27 ± 0.10 mm) and Manuka 20+ honey (16.52 ± 0.12 mm). The antimicrobial activity of Chinese honey depends on hydrogen peroxide. 2. The total antioxidant capacity of Fennel honey, Agastache honey, and Pomegranate honey was higher than that of other Chinese honeys. There was a significant positive correlation between the total antioxidant capacity and the total phenol content of Chinese honey (r = 0.958). The correlation coefficient between the chroma value of Chinese honey and the total antioxidant and the diameter of inhibition zone was 0.940 and 0.746, respectively. The analyzed dark honeys had better antimicrobial and antioxidant activities. 3. There were significant differences in volatile components among Fennel honey, Agastache honey, Pomegranate honey, and Manuka honey. Hexanal-D and Heptanol were the characteristic components of Fennel honey and Pomegranate honey, respectively. Ethyl 2-methylbutyrate and 3-methylpentanoic acids were the unique compounds of Agastache honey. The flavor fingerprints of the honey samples from different plants can be successfully built using HS-GC-IMS and principal component analysis (PCA) based on their volatile compounds. Fennel honey, Agastache honey, and Pomegranate honey are Chinese honey varieties with excellent antimicrobial properties, and have the potential to be developed into medical grade honey.     

Multinuclear magnetic resonance study of some mesoionic oxatriazoles containing nitrogenous exocyclic groups

¹H,¹³C,¹⁴N and¹⁵N NMR measurements are reported for four mesoionic 1-oxa-2, 3, 4-triazoles containing exocyclic nitrogenous groups. The NMR signal assignments are discussed and compared with those previously published for some corresponding oxatriazoles. The results obtained support the proposed cyclic mesoionic structures for the compounds studied. The questions of possible charge delocalization and valence tautomerism are addressed. Compound with N^– H as a exocyclic group (Fig. 1) is found to be relatively unstable, this is attributed to proton migration in the corresponding non-cyclic form of this molecule.Published in Khimiya Geterotsikiicheskikh Soedinenii, No. 9, pp. 1260–1263, September, 1995.